Prusa Slicer Changelog

What's new in Prusa Slicer 2.7.4

Apr 5, 2024

Improvements:
Objects from 3MFs generated by BambuStudio now retain multimaterial painting when loaded. BambuStudio saves the data under a changed name, but because both the location and meaning are the same, PrusaSlicer now tries to load the data under the new name when it fails to find the attribute that PrusaSlicer has always used.

New in Prusa Slicer 2.7.3 RC 1 (Mar 27, 2024)

New in Prusa Slicer 2.7.3 Beta 1 (Mar 26, 2024)

New in Prusa Slicer 2.7.3 Alpha 1 (Mar 21, 2024)

Spiral vase mode improvements:
When using spiral vase mode, the toolpaths are generated as usual and the resulting extrusions are then extruded while gradually increasing z. This approach led to seam-like artifacts on the print in places where the layer transitions would normally be (#4116, #2841). In addition, the last layer would end abruptly, creating a sharp "edge" where the extrusion ends.
Both these issues were addressed by @andrewboktor by interpolating between adjacent layers and by gradually reducing extrusion flow at the very end of the print. The improvement was recently merged into OrcaSlicer (SoftFever/OrcaSlicer#3091), and we got a pull request with a port to PrusaSlicer. After we evaluated the feature, we decided to merge it because it is well written, well working and very useful.
Thanks to @andrewboktor for the time and effort invested into the issue, and to both @vovodroid and @tg73 for providing a pull request with a port from OrcaSlicer (#12079, #12142).
Other improvements with respect to 2.7.2:
PrusaSlicer is now able to open 3MF files generated by BambuStudio and load geometry from them. (#10718, PR #10808, thanks to @cmguo). Please note that BambuStudio allows to save a 3MF containing G-code only, which is not supported by PrusaSlicer and loading of such 3MFs will fail.
Metadata of binary G-code have a new item named objects_info, which lists all the objects in the print and their boundary polygons. The same info was added into the comments at the end of ASCII G-codes.
Bugfixes with respect to 2.7.2:
Pressure equalizer limits were not respected when Dynamic speed on overhangs was used (#9485). This is now fixed. Pressure equalizer is also not applied after long travels. Many thanks to @MGunlogson for providing a fix in his pull request #9622.
Fixed a bug resulting in inadequate anchoring of bridging extrusions. This bug was introduced in PrusaSlicer 2.6.0. #10231, #11500, #11633, #11173, #11117, #9999, #10313, #11150, #10493
When using Cancel object feature, the marks denoting where one object ends and another starts were placed incorrectly. As a result, there was a missing deretraction after all travels to objects which would normally be printed following the cancelled object. The issue was even worse with sequential printing, where the uncompensated retractions on the cancelled object summed up and could result in filament being unloaded past the driving gears.
When arcs (G2 and G3 G-codes) were enabled, PrusaSlicer generated toolpaths outside the print area in certain cases (#12381).
Translations:
Updated POT
Added Slovenian translation (#12422, thanks to @jernejp21)

New in Prusa Slicer 2.7.2 (Mar 1, 2024)

New in Prusa Slicer 2.7.2 RC 1 (Feb 24, 2024)

New in Prusa Slicer 2.7.2 Beta 1 (Feb 21, 2024)

New in Prusa Slicer 2.7.1 (Dec 14, 2023)

New in Prusa Slicer 2.7.0 (Dec 3, 2023)

New in Prusa Slicer 2.7.0 RC 2 (Nov 22, 2023)

New in Prusa Slicer 2.7.0 RC 1 (Nov 16, 2023)

Summary:
This is the first release candidate of PrusaSlicer 2.7.0. It mostly fixes bugs found in the 2.7.0-beta1. Read the change log of 2.7.0-alpha1 and 2.7.0-beta1 for complete list of changes with respect to 2.6.1.
The release candidate saves its profiles into regular PrusaSlicer configuration directory. When you first run it, it will search for all configurations produced by alpha or beta versions and offer to create a copy of the latest one.
Improvements with respect to 2.7.0-beta1:
PrusaSlicer 2.7.0-alpha1 introduced the binary G-code format. The new format is enabled in our system profiles for Original Prusa MINI, XL and MK4 printers, but it requires that the printer firmware is updated. Old firmware would not show the binary G-code files at all. Based on the feedback that we collected, this was a frequent problem and a source of confusion. Therefore, we decided to add an extra dialog informing the user about the need to update firmware. The dialog is shown when exporting binary G-code for the printer models mentioned above, and it contains a "Don't show again" checkbox, which dismisses the dialog for good.
Bug fixes with respect to 2.7.0-beta1:
macOS specific: Fixed a crash when modifying purging volumes (#11627).
It was not possible to change selection in a focused combo boxes using the mouse wheel (#11640).
Fixed a crash when opening the Shape Gallery (#11681).
macOS specific: Fixed occasional failures to upload G-code to PrusaConnect. The problem was possibly caused by a bug in libCURL library shipped with the affected macOS versions (possibly curl/curl#11353). We worked around the problem by using HTTP/1.1 for libCURL requests (#11076, #11355, #11399).
The helper arrows in the scene indicating direction when a value in Object Manipulation is being edited were not shown by mistake (#11636).
Overhang fan speed was not reset before printing infill, which is now fixed. Thanks to @jschuh for debugging the issue and providing a fix (PR #11650, #11648).
Fixed a possible crash when deleting the last object with auto-center enabled (#11186).
Fixed incorrect placement of checkboxes in some of the dialogs.
Linux specific: Fixed appearance of checkboxes in GTK2 version (#11664).
Fixed updates of some Preferences options, e.g. when it changed as a result of "Remember my choice" checkbox in some dialog.
Focus of spin controls did not work correctly in Config Wizard and Ramming dialog.
Linux and macOS specific: Colors in the combo boxes did not change when system settings were changed (#11556).
File names in the Shape Gallery were cut short (#11642).
Fixed a hang occasionally happening during Arrange (#11392).
When loading a 3MF containing a profile based on a system profile which is currently not installed, an incorrect preset was sometimes chosen instead of the temporary installed preset. Also, a notification is now shown when the temporary preset is installed (it was inadvertently removed in 2.7.0-alpha1).
In certain cases, materials and filaments in Configuration Wizard were incorrectly marked as not compatible with the printer.
When loading a 3MF with multiple filament profiles, some of the profiles were incorrectly marked as modified, even though they were not.
Infrastructure:
Update build_win.bat max version to Visual Studio 2022 (PR #11646, thanks to @jschuh, related to #11635).
Updated build instructions for Windows, added deps/README.md containing details about building dependencies.
Translations:
Updated CS, DE, ES, FR, IT, JA, PL dictionaries
Catalan dictionary updated (#11641, thanks to @davidjuanesb).
Russian dictionary updated (#11559, thanks to @AndylgTom).
Updated POT file for community translators.

New in Prusa Slicer 2.7.0 Beta 1 (Nov 13, 2023)

Travel moves improvements:
To help fight stringing and oozing deposition, PrusaSlicer now implements ramping travel moves. Previously you could set just the Lift height (Printer Settings->Extruder) which resulted in the print head lifting up before each travel move and then returning back down after the travel move. Such lift could result in undesirable stringing, especially while using wider nozzles. Now you can use the new ramping lift which ensures that the print head lifts up gradually during the travel.
The feature can be turned on in Printer Settings->Extruder for each extruder you are using in the new Travel lift section. You can override the setting for each filament in the Filament overrides section. The ramping travel is parametrized by an angle and a maximal ramping lift.
The ramping travel moves are now enabled in our system profiles for Original Prusa XL.
To fully harness the stringing reduction potential of the ramping travels moves a new layer change strategy is implemented while the ramping travel moves are active. Instead of going straight up to the next layer the printer head follows a helical ("screw thread") trajectory while changing layers. This feature is on by default once the ramping travel move is used.
The helical travel move was inspired by the same feature in BambuStudio. Thanks to bambulab for the idea.
Other improvements with respect to 2.7.0-alpha1:
After we collected feedback to the UI improvements presented in the previous alpha, we did several tweaks to the combo boxes. They react better to keyboard input, the spacing of the items is smaller, the scrollbar has been made wider and it allows dragging by mouse (#11499, #11505).
Arrange is now faster in processing more complex scenarios (#11360).
The thumbnails in the G-code are now colored correctly even when using the painting tool.
A notification suggesting to upload Wi-Fi configuration data is opened when USB flash drive containing the configuration file is inserted. PrusaSlicer is then able to append the Wi-Fi data into the file.
When PrusaConnect print host is selected in the Physical Printer dialog, the Browse button is now hidden as it would make little sense. When confirming the dialog, the URL field is checked and if it contains anything different from https://connect.prusa3d.com, the user is asked to confirm that it is intentional.
A notification suggesting to upload Wi-Fi configuration data is opened when USB flash drive containing the configuration file is inserted. PrusaSlicer is then able to append the Wi-Fi data into the file.
The SVG dialog contains an extra button "Face the camera", which rotates the SVG so it is perpendicular to current view direction.
Trying to exporting ASCII G-code with binary G-code extension or vice versa is now reported as an error (#11498).
Colors of selected volumes in the scene were slightly changed so the negative volumes are visible even when selected (#11496).
Bug fixes with respect to 2.7.0-alpha1:
The new "Wi-Fi Configuration File" dialog did not show correctly in dark mode and it did not use the new UI controls.
Cancel object G-codes were not correctly emitted for RepRapFirmware and the objects were not labeled as a result (#11492).
In some scenarios, an item in a combo box was duplicated.
When using the cut tool and assigning a part of the model to the other side, connectors were missing after slicing (#11415, #11487).
Fixed a rare crash when using 'Split to Objects' (#11484).
Password authentication did not work correctly when sending G-code to Duet SBC (#10061).
Perimeters were not generated when using Arachne perimeter generator with specific configuration (#11082, #11510).
The wipe tower was not generated correctly when non-zero extruder offset was used.
Number of tool changes in the statistics only showed when the wipe tower was enabled (#6832).
When slicing with the wipe tower enabled and then disabling it, PrusaSlicer sometimes ended up in an infinite loop.
Fixed incorrect label object markers at the start of the G-code when it was set to "OctoPrint comments" and the firmware flavor was Klipper (#11569).
Fixed a UI glitch related to the scrollbar in Preferences dialog (#11566).
Fixed invalid link to Organic Supports documentation (#11555).
When using the experimental option "Wipe tower with no sparse layers", a travel move to the wipe tower was sometimes missing, which resulted in the print head digging into the last printed object (#11089).
Spin controls which allow setting the value negative now accept minus sign input from the keyboard (#11574).
When configuring a physical printer, the IP address was not always correctly read from the text field, resulting in failed uploads later on.
Fixed a crash when slicing a sinking object with multiple instances (#11562).
Fixed synchronization of instances when rotating an instance in Object Coordinates.
Fixed a bug resulting in monotonic infill was not being monotonic (#11565).
Fixed crash in multi-material painting gizmo and during generating multicolor thumbnails when number of extruders was changed.
Other:
3DBenchy model and template models for signs were added to Shape Gallery.
Translations:
Updated POT file for community translators.

New in Prusa Slicer 2.6.1 (Sep 6, 2023)

New in Prusa Slicer 2.6.1 RC 2 (Sep 2, 2023)

New in Prusa Slicer 2.6.1 RC 1 (Aug 23, 2023)

New in Prusa Slicer 2.6.0 (Jun 20, 2023)

New in Prusa Slicer 2.6.0 RC 2 (Jun 14, 2023)

New in Prusa Slicer 2.6.0 RC 1 (Jun 10, 2023)

New in Prusa Slicer 2.6.0 Beta 4 (Jun 3, 2023)

New in Prusa Slicer 2.6.0 Beta 3 (May 27, 2023)

New in Prusa Slicer 2.6.0 Beta 2 (May 17, 2023)

New in Prusa Slicer 2.6.0 Beta 1 (May 14, 2023)

With this release, PrusaSlicer not only brings fixes but also introduces several noteworthy improvements to existing features. Highlighting the most significant enhancements, the Cut tool has been upgraded to provide increased power and functionality, Organic supports have undergone improvements to enhance stability and reliability, and modifications have been made to improve compatibility presets for multitool printers.
To let you enjoy the beta without worries, the beta builds save their profiles into the PrusaSlicer-beta directory, so you may use the beta side by side with the current release without ruining your production configuration. When you first run the beta, it will search for all configurations produced by alpha or final versions and offer to create a copy of the latest one.
Upgrades of the Cut Tool for selective object splits #9472, #9577, #9922:
The improved Cut tool now offers more flexibility by allowing users to selectively select parts of the object which should not be cut. Selection and deselection of the parts can be controlled with the right mouse button. Note that when some parts are selected, PrusaSlicer will always generate two separate objects, the option to leave everything as parts of one object is not available.
Changes in modification of compatibility of presets:
When using a Multitool printer (with 'single_extruder_multi_material' turned off), PrusaSlicer now filters filament presets and presents the user with only the appropriate filaments based on the compatible printers conditions ('compatible_printers_condition') for each individual extruder. This change also introduces a new combobox in the Filament settings, simplifying the listing of extruders.
Other improvements with respect to 2.6.0-alpha6:
Embossed text objects can now be edited in Simple mode.
When using MainSail/Fluidd print host, PrusaSlicer now uses Moonraker API, without relying on OctoPrint compatibility mode being enabled.
A new ‘Hide/Show Custom G-Code’ button was added to the G-Code preview. The range of color scale in the legend is possible to visualize without the effect of the purge line. The button is available only for parameters where it is relevant (Width and Volumetric flow rate) #10259
Improved error reporting when the last layer exceeds the maximum build volume height due to variable layer height. The name of the object violating print height is reported. Improvement is related to original issues. #9467 #9519 #9646
macOS specific: Fixed performance issue with the G-Code viewer when travels were enabled.
Added 'Zoom to mouse cursor' by Shift+Mouse wheel. Thanks to @LiZ-Li-BBL
Thumbnails generated to G-code now use the same colors as in the 3D view. #4577
The slicer now includes an improved algorithm for overhang speed slowdown and avoiding curled filament. A new and tuned estimation method is applied for the curled height of the filament. The estimated curling now affects the slowdown of overhang speed on external perimeters and also on internal ones. #9756. The new enhancement should significantly improve surface quality and prevent artifacts, without slowing down internal perimeters unnecessarily.
After slicing an object with negative volumes in SLA mode, users now have the ability to toggle the visualization on or off, allowing for better control over the final geometry in the 3D editor. This convenient new button for switching between visualizations is located adjacent to the object, facilitating an intuitive user experience.
New ensuring addresses the occasional occurrence of local zig-zag patterns that were generated in the ensuring perimeters. It detects segments with short movements that cause vibrations and can reduce surface quality, and fixes them. #9970
Improvement of Organic supports by preventing collisions between the main object and its own support branches. Note that the collision issue between different objects and their support branches remains unresolved. #10247
The bottom interfaces of Organic supports have been fixed and enabled, providing enhanced stability when positioned on the model's body. #9512
The user now has control over the utilization of either one or two perimeters for Organic supports using the support_tree_branch_diameter_double_wall parameter. #10304
Improvements in bridges over internal infill:
Improved the algorithm so it does not generate extremely long bridges when the layer below is very sparse. #10222
PrusaSlicer now detects areas where internal bridges require anchoring to perimeters and enhances it by adding an extra ensuring line in the previous layer. This addition provides support and enhances structural stability for the bridges.
Furthermore, PrusaSlicer has improved the handling of internal bridges when using Lightning infill. It expands the Lightning infill around bridged surfaces, ensuring improved anchoring for a greater number of bridges.
Bugs fixed with respect to 2.6.0-alpha6:
Fixed crash at startup of PrusaSlicer when any of the SVG files used as icons in dialogs is renamed or removed.
Fix of Undo-Redo mainly for Emboss text tool. Undo-Redo will not add new parts after the text edit is closed.
Fixed crash in SLA, when an instance of the object is selected after slice.
Resolved the issue where the speed was not reset correctly after travel when dynamic fan speed was enabled. This caused travel speeds to be used for printing. #10229
Refactor of export archives for Anycubic Photon Mono and Mono SE printer. Thanks to @Mimoja #9929
The Ensuring algorithm was filtering perimeters too aggressively causing several issues, including making holes in top surfaces with low inclination (#9978), some bridges not being anchored properly into perimeters (#10231), and non-anchored solid fill when slicing with one top/bottom surface and very low minimal shell thickness. #9988
Fixed a rare crash in Placeholder parser, when the respective Custom G-code contained specific erroneous syntax. #10183
The wrong flow was used for spacing of internal bridging over infill causing an error when a small nozzle diameter was used or a small layer height was applied.
The 'Dynamic overhang speed' feature applied volumetric limits incorrectly for some overhangs. By now for a zero input value, the external perimeter speed is used instead. #10269
Fixed ‘Bad function call’ without any obvious reason for Organic support. #9892
Fixed height detection when using sequential printing. #10312
Linux specific: Fixed object disappearing when opening SLA hollowing or support gizmos.
The issue of broken object indexing for the 'Label object' feature has been fixed by assigning an incremental index randomly to each object and adding relevant comments, making it easy to cancel objects in OctoPrint and other applications. #10257
Fixed error when adding instance to a mirrored object.
When adding an instance use the orientation of the currently selected instance.
Fixed a crash when sending G-codes to "Mainsail/Fluidd" print host (introduced in 2.6.0-alpha6). #10210
Resolved the issue where entering too low or too high values for parameters Branch Diameter and Tip Diameter resulted in errors such as "Divided by zero" or caused the software to crash. #10385
Windows specific: Fixed the issue where disconnecting an SD card that was connected via an external card reader would also disconnect the card reader, requiring it to be disconnected and reconnected to be loaded again. The new code also triggers Windows notifications. #9881
Fixed the issue where the SLA support gizmo was inactive and was not possible to slice due to invalid data. The issue was triggered by attempting to hollow an object without proper settings.
Fix of crash upon loading a 3mf project with cut objects. #10319
Fixed occasional crash in Organic supports. #9665
Fix an issue where the 'Place on Face' gizmo did not work correctly with instances, causing the marks on the surface to be inactive for added instances.
Fixed a crash that occurred when an object placed outside of the print bed was arranged. #10241, #10278, #10416
Fix of crashes in the Support Point and Hollowing gizmos when used with non-printable objects. As a result, SLA supports and Hollow gizmos are now disabled when a non-printable object is selected, and users are prevented from setting an object to non-printable while these features are active.
Fixed occasional crashes during arrange.
Resolved issues when rotating individual instances around the X or Y axis (crash on macOS, incorrect selection on Windows and Linux).
Fixed a bug in the rounded extrusion calculation. This issue caused inconsistent bridge extrusion widths for different 'bridge_flow_ratio' values. #9007
Fixed a crash that occurred when loa...

New in Prusa Slicer 2.6.0 Alpha 6 (Apr 1, 2023)

Other improvements with respect to 2.6.0-alpha5:
'Arrange' and 'Fill bed with instances' functions now take into account skirt and brim separation (#3072, #3477, #5286, #5310, #9301, #9309). Many thanks to @jschuh (#7653) and @individ-divided (#9181), whose pull requests were very useful sources of inspiration, despite not being used verbatim.
The 'Export as STL/OBJ' function is now able to subtract negative meshes. Note that the algorithm may fail on non-manifold geometries (e.g., those containing self-intersection, etc). In that case, the user is notified, and only positive volumes are exported. #9798 #7594 #8853
The configuration option Only infill when needed was removed. It never worked well, and it was a frequent source of confusion and bug reports when it removed infill from places where it was desirable or vice versa (#9790, #8381, #7914, #6286, #5791, #4916, #2796). The option is superseded by Lightning infill (#8648) and the feature has become too much of a maintenance burden, leading to problems when implementing new features #9935.
The 'Purging volumes' settings accessible by a button in the right panel is now only shown and used for single-extruder multi material printers. Setting purging volumes based on which filament is unloaded does not make sense for proper multi-extruder systems, which can easily control the required purging in Filament Settings->Advanced->Minimal purge on the wipe tower. Note that this is potentially a breaking change, affecting non-single MM profiles with the 'Purging volumes' set much higher than the value in filament settings, in which case the wipe tower will become smaller than it was in previous PrusaSlicer versions.
The wipe tower can optionally be printed with a "stabilization cone", which prevents it from toppling over. The apex angle of the cone is adjustable in Print Settings->Multiple Extruders->Wipe tower. Setting the value to zero disables the cone.
The spacing of purging lines on the wipe tower can be increased using another new configuration option in Print Settings->Multiple Extruders->Wipe tower
The size of the wipe tower preview block the 3D scene should now be more precisely estimated
When switching to 3D scene after slicing in SLA mode, the pad and support trees are now shown as they were in 2.5.x. This functionality was temporarily removed in 2.6.0-alpha2 because of issues it caused when using negative meshes (which was not possible in 2.5.x).
Print bed reference axes are now automatically downscaled when zoomed in #9483
The pointy ends of 'Frustum'-type connectors produced by the Cut tool are now slightly trimmed
When an edge is selected in the Measurement tool, its length is shown in the measurement dialog
It is now possible to set separate acceleration for travel moves in Print Settings->Speed->Acceleration control. The value is clamped by the maximum travel acceleration in Printer Settings->Machine limits when using Marlin 2 or RepRapFirmware flavor.
The M107 (turn fan off) command emitted at the beginning of the G-code was removed
For a long time, PrusaSlicer would scan the Start G-code and insert temperature-setting commands when they were not present. This feature is now optional and is controlled by a new configuration checkbox named "Autoemit temperature commands".
'Save/Rename Preset' dialog was simplified when only one preset is being saved/renamed.
Organic supports: reduced default support_tree_top_rate to 15%
Estimated print time for the first layer was added as a comment at the end of the G-code, supplementing similar information already available
The text tool behaves better when positioning text on an object with multiple instances
The text tool now has a lock switch next to 'Rotation' field in the Advanced controls. This allows to unlock the free rotation. It is for dragging text over the surface without orientation jump.
Constrained scaling (scaling using the scale tool while pressing the CTRL key) can now be used with any selection
Bugs fixed with respect to 2.6.0-alpha5:
The reference axes at the origin were incorrectly rendered on top of objects when viewed from the bottom of the bed
Filament type dropdown did not accept user editable text #9770
Extra perimeters on overhangs were printed in the air when the external perimeters option was enabled #9545
The cut tool did not place the pins and holes correctly when used on an object with scaling applied #9991, #10010, #10056, #10096, #10126
Export STL did not export anything when the file extension entered in the Save dialog was not lowercase #10000
Fixed a hang in rare cases when calculating Organic supports #10048
The new bridging algorithm that extends bridge infill over sparse infill now works with Adaptive Cubic and Adaptive Support infill types. The only infill type that is not yet supported is Lightning infill.
The bridge angle setting was incorrectly interpreted as if it was in radians instead of degrees #9963
Fixed an incorrect bridging angle in some cases #10086, #9895
The new bridging algorithm generated overextrusions when 'Thick bridges' were enabled #10073
The new bridging algorithm was extremely slow in certain cases #10049
The new bridging algorithm sometimes extended the bridging extrusions too much (mentioned in #9245 (comment))
When 'Disable fan for first N layers' was enabled, the 'Fan speed on overhangs' feature did not work correctly (#9975, thanks @jschuh)
Fixed a false positive warning about stability issues, sometimes appearing on simple models with straight walls #9744
Fixed a crash when using add instance function with the wipe tower selected
Several layout issues were fixed #9768
It was not possible to export multi-extruder config when some filaments had idle_temperature checked and others did not #10163
Fixed an error sometimes reported when slicing in SLA mode
macOS specific: Fixed a crash in the text embossing tool when moving a text with on an object partially below the bed
Fixed incorrect selection in Object list when moving a part of an object below the bed (or from below the bed)
Fixed a bug in Organic supports that caused the trees to cut through an object in some cases
Fixed a hang in the Arachne perimeter generator with specific geometries #10034
Improved eject function on Windows. Since our code added to 2.6.0-alpha2 is having issues with external SD card readers, we have added a detection of such devices (based on https://github.com/microsoft/Windows-driver-samples/tree/main/usb/usbview). Detected external SD card readers are ejected using the code from 2.5.0 and older. We are aware that the older approach might eject devices too early...

New in Prusa Slicer 2.5.2 (Mar 30, 2023)

New in Prusa Slicer 2.5.1 (Mar 15, 2023)

New in Prusa Slicer 2.6.0 Alpha 5 (Mar 6, 2023)

It is now possible to import ZIP file contents from File->Import->Import ZIP Archive. A dedicated dialog is shown, and the user can select which of the files in the ZIP archive they want to open.
Organic supports can now be used with raft. Raft is built for the object only. Organic supports are routed directly to a print bed, they are not supported by a raft. #9816, #9743, #9526
Raft interface / contact layers are newly produced with alternating directions, and raft contact layer is newly perpendicular to a fill direction of the first object layer.
The configuration of Dynamic overhang speed was simplified, the percentage levels for which the speeds are set are fixed at 0/25/50/75 %.
There is a new is_nil function available in custom G-Codes to check whether a given configuration option is currently inactive (such as idle_temperature in Filament Settings). Example usage: {if is_nil(idle_temperature[0])}...{else}...{endif}
Wipe tower brim was not shown in the 3D scene after slicing was finished
Tool temperature visualization in Preview was incorrect in some cases (related to #8324 and #9597)
macOS specific: Text emboss input dialog did not allow pasting text from the clipboard #9795
"Avoid crossing curled overhangs" sometimes generated travel moves outside of the bed #9800
Fixed "Dynamic overhang speed" when Pressure equalizer was used #9485
Fixed a crash in G-Code Viewer when parsing G-Code generated by Simplify3D #9823
G-Code Preview did not account for z offset when setting the height of the toolpaths for the purge line in custom start G-Code #9722
Fixed a crash when trying to add instances when multiple objects are selected #9864
Various minor improvements and bugfixes in the Cut tool #9771
Fixed a bug that incorrectly triggered an "out-of-bed" error when specific transformation was applied. The same problem caused issues when changing variable layer height #9467 #9519 #9646
By pressing the 'T' keyboard shortcut, it was possible to add text to an object that was created by a cut and had connectors. This is now fixed, as this is an unsupported scenario.
Fixed a crash sometimes occurring on startup on macOS Ventura 13.2.1 #9774
Reload from disk was not available for 3MF files #9822
Fixed a crash when cutting an object containing a modifier

New in Prusa Slicer 2.6.0 Alpha 4 (Feb 18, 2023)

Cut Tool Improvements:
The Cut tool dialog layout was changed to be easier to comprehend
Upper and lower part of the object are now highlighted in color
Added a possibility to cut the object into parts - in that case, connectors cannot be placed and the parts retain its position within the object. Thanks @jschuh for this idea (presented in #9564).
The controls of the tool obscured the object when it was small
Added a functionality "Flip cut plane" to easily add pins to the other side of the plane
The cut tool now works even when the cutting plane does not intersect any volume of the object, so the tool can be used to separate parts into multiple objects without actually cutting anything. This is the same behavior as in 2.5.0.
When placing connectors in the new Cut tool, the tolerance is now entered in absolute values
The cut plane is now highlighted on hover, it is newly possible to move it by dragging.
If the object is cut into parts or when it does not have any connectors, the "lock" of scaling of the resulting parts is not applied
Performance improvements
Other improvements with respect to 2.6.0-alpha3:
The option "Clip multipart objects" was removed. PrusaSlicer now always behaves as if it was ON. This option was a candidate for removal for a long time, and the new algorithms we implemented for the 2.6 series are no longer compatible with it. We believe that there is really no reason not to clip the objects and we have seen many cases where leaving it OFF accidentally led to unexpected results (overlapping extrusions) #9679, #8779, #3872
Increased sensitivity of the curled overhang avoidance algorithm
'Set Number of Instances' now works when multiple objects are selected
Organic supports are now consistently referred to as 'Organic'
Organic supports parameters are now grayed out when different style of supports is selected
It is newly possible to set acceleration separately for external perimeters, solid infill and top solid infill (Print Settings->Speed->Acceleration control)
Bugs fixed with respect to 2.6.0-alpha3:
Extra perimeters on overhangs sometimes overlapped with infill
Fixed an occasional crash when using Organic supports with specific settings
Fixed a crash during slicing when certain strings were present in custom G-codes. This was also a problem in previous versions, but instead of a crash, incorrect cooling logic might have been applied in these cases,
The "Export plate as STL including supports" option was grayed out in the menu when the object only had pad and no supports
Organic supports: All contours are CCW oriented, inner contours are printed before outer contours.
Fixed crash in Organic supports with a single support layer only
Linux specific: The new "idle_temperature" option in Filament Settings did not behave correctly when checked and unchecked (UI glitches).
Fixed a rare crash during slicing with specific geometries,
"Verbose G-Code" option produced invalid G-Code when "Dynamic overhang speed" was enabled
Cooling slowdown was applied incorrectly when "Dynamic overhang speed" was enabled
"Dynamic overhang speed" would set speed to zero if the speed was percentage based and external perimeter speed was set to 0 (auto). Thanks @MGunlogson for helpful investigation of this issue in #9622.
"Dynamic overhang speed" could violate (volumetric) speed limits #9709. Thanks @MGunlogson for helpful investigation of this issue in.
"Dynamic overhang speed" did not work correctly with Pressure equalizer feature.
The "optional" config option idle_temperature now retains its value when disabled and enabled again. If the value cannot be recovered (e.g. after switching to different tab), a value of 30 is used as a default instead of 1500. Previously, the value would change to 1500 (maximum allowed temperature) when the option was reenabled. Same fix was applied to options in Filament Overrides.
When using the Cut tool on a model that was scaled, the manipulation arrows in the scene had incorrect size and the plane was not exactly in its correct position.
Fixed double-printing of support layers in specific scenarios with soluble supports and interface layers
Organic support branches sometimes intersected interface layers
Organic supports did not correctly work when using "Enforce supports for the first N layers" option
Organic supports did not correctly work when using "Don't support bridges" option
Various bugfixes and improvements of the Organic supports, thanks @ThomasRahm
Organic supports ignored overhangs in specific cases, thanks @ThomasRahm
Fixed missing update of sidebar panel after orienting an object using Place on Face tool
Experimental option "Wipe tower with no sparse layers" did not work correctly and was causing missing layers in the print
The Cut tool could not be applied consecutively when the previous cut placed exactly one connector
Fix of Physical Printer Dialog: When closing and reopening the dialog, "Host Type" field was incorrectly changed
The new placeholder is_extruder_used introduced in 2.6.0-alpha2 was not expanded correctly in some cases.
Several issues with object manipulation were fixed (mostly affecting mirrored objects)
Linux specific: Desktop integration and URL registration are now separated.
Layout fixes in the Preview dialog when an archive is being opened.
Fixed freezing during brim generation for specific geometries
Windows specific: Selected item in Search dialog was unreadable when using dark mode
The new autopainting of supports did not work correctly when raft was enabled
Fixed a crash with specific geometries and elephant foot compensation enabled
Bugs fixed with respect to 2.5.0:
Linux specific: desktop integration was failing when $XDG_DATA_HOME and $XDG_DATA_DIRS environment variables were undefined
Windows specific: Fixed UI glitch in PhysicalPrinterDialog when changing the printer selection
Extruder temperature was occasionally shown incorrectly in Preview when using single extruder multi material
Fixed a false positive error report about "Calling AppConfig::save() from a worker thread", appearing when using VM and specific nVidia drivers
Profiles:
Added initial MakerGear bundle

New in Prusa Slicer 2.6.0 Alpha 3 (Feb 3, 2023)

New in Prusa Slicer 2.6.0 Alpha 2 (Jan 31, 2023)

Organic supports:
Until now, PrusaSlicer's supports consisted of 2D "scaffolding" created on a regular 2D grid. While the approach produced reasonably good results in many cases, they often consumed quite a lot of filament, took a long time to print, ended up in spaces where they are difficult to remove from and left visible scars on the model when removed (especially when the settings were not tuned correctly). We improved some of these downsides by introducing the "Snug" supports in PrusaSlicer 2.4.0, but they are still an upgraded version of the old and limited approach.
Measurement tool:
Measurement tool is another feature long demanded by our community. The tool utilizes a geometry detection algorithm that recognizes points (vertices), edges, circles and planes. Users can check model sizes and angles directly in the slicer, so there is no need to open 3rd party software anymore for this purpose. At the moment, it is possible to measure between parts to simplify their better manipulation and organization inside objects (but not between separate objects). Last but not least, the tool allows to uniformly scale the object to the required length by clicking a button in the scene.
Text embossing tool:
This tool opens a new capability to insert, manipulate and edit text created like a new volume of an object. It allows to add notes, signs, serial numbers, etc. directly in the slicer.
Cut tool update:
The Planar Cut tool has been available in PrusaSlicer for a long time. It is handy for preprocessing huge models that don't fit the build volume, are too complicated to print in one piece, or models where only a part is valuable for the user. With this release, we decided to extend its functionality.
Automatic FDM support painter and print checker:
For a long time, PrusaSlicer allows the user to paint areas to be supported. This is a much praised feature that allows the user to customize supports quickly and easily. As part of a large effort to create more intelligent support creation, the FDM support painting tool now contains an option for automatic painting of enforcers on the model. The algorithm behind this tool checks the print extrusion by extrusion and takes into account many factors such as the center of mass, weight of the supported part, bed movement, potential extruder collision, bed adhesion, material, and bridging. The result should be more effective support placement. For example, bridges are supported only on regularly spaced pillars and not over their full length.
Dynamic overhang speed:
Dynamic overhang speed functionality enables reliable slowdown of overhang extrusions. Lower velocity enables proper cooling when it is needed. The algorithm calculates extrusion overlap with the previous layer and applies speed calculated from the overhang slowdown function.

New in Prusa Slicer 2.5.0 (Sep 7, 2022)

New in Prusa Slicer 2.5.0 RC 2 (Aug 30, 2022)

New in Prusa Slicer 2.5.0 RC 1 (Aug 20, 2022)

New in Prusa Slicer 2.5.0 Beta 1 (Aug 15, 2022)

Bugfixes with respect to PrusaSlicer 250-alpha3:
Contours shown in the Cut tool were not properly updated after object orientation or scale was changed
When opening any gizmo using a keyboard shortcut, its input window now shows immediately, not after the first mouse move
Fixed crashes appearing in Arachne perimeter generator with certain models #8474, #8514
Prevented gap fill and Arachne from creating tiny gaps in extrusions in specific cases
Fixed an issue when an open perimeter containing part of an overhang perimeter was split into two parts and wasn't extruded as continuous extrusion
Fixed a bug in the pressure equalizer which would hang or produce extremely fast printing speeds in some cases #8457, #8461
Fixed a bug in Arachne perimeter generator which would sometimes produce artifacts not present on the original model #8446
Prevented the pressure equalizer from emitting G1 Fx lines which would not affect any actual extrusions
Fixed an issue with wall_transition_filter_deviation config option, which was evaluated incorrectly when set a percentage
Fixed an issue with the Arachne perimeter generator: a middle perimeter was missing in some specific scenarios #8472
Fixed unintentional deceleration before ironing caused by pressure equalizer The same issue affected gap fill #8530
Fixed pressure equalizer not slowing down before bridge infill
Fixed a bug in the seam placer which sometimes placed seams on overhangs
When using seam painting, some of the resulting seams would occasionally be incorrectly placed close to the edge of the painted area #8600
Fixed a failing assertion in Arachne on Windows (the assertion was harmless) #8597
'Unprintable' state is now maintained after merging parts together #8668
Fixed printable state update after splitting an object
Translations:
Updated CS, DE, ES, FR, IT, PL translations
Updated zh_CN translation (#8544, thanks @iBral)
Updated pt_BR translation (#8673, thanks @valterfc)
Profiles:
Added Elegoo bundle (Neptune printers) (prusa3d/PrusaSlicer-settings#162, thanks @mlee12382)
Added new Creality printers (Ender-3 V2 Neo, Ender-3 Max Neo, CR-10 SMART Pro) (#8602, thanks @pmjdebruijn)
Updated Creality profiles (#8602, thanks @pmjdebruijn)

New in Prusa Slicer 2.5.0 Alpha 3 (Jul 15, 2022)

New in Prusa Slicer 2.5.0 Alpha 2 (Jun 30, 2022)

Arachne perimeter generator:
The 'classic' strategy for calculating perimeter extrusion paths is to offset contours of an object slice inwards by a constant extrusion width, one offset per perimeter. This was also the default algorithm in previous PrusaSlicer versions. However this simple algorithm does not handle thin regions well, as reported in these issues. Namely, thin regions cannot be filled with an integer number of fixed width extrusion lines. The classic way of handling narrow regions is to either not generate the innermost perimeter that does not quite fit, but to fill the remaining region with a gap fill algorithm, or to over-extrude the innermost perimeter. None of the two approaches are ideal: The gap fill may produce short segments of widely differing extrusion rates, while over-extruding may produce bulges on thin walls.
The developers of Cura recently implemented a new strategy named Arachne based on paper [Kuipers et al., 2020]. The Arachne generator produces perimeter loops and gap fills with varying extrusion width in such a way, that the slice area is filled without underflows and overflows with possibly continuous paths while respecting minimum / maximum extrusion width limits. The Arachne perimeter / gap fill generator really shines on objects with thin walls as thin boxes or labels.
In this PrusaSlicer version, we have ported the Arachne engine from Cura while keeping the old perimeter generator as an option. We made the Arachne perimeter generator default in our printer profiles. Thanks again to Ultimaker for developing Cura under open license.
Lightning infill:
Infill serves dual purpose: To provide structural rigidity and to support top surfaces. In case the structural rigidity is not needed, a lot of material and printing time is saved with the new lightning infill, that is optimized to supports the top surfaces only. The lighting infill is based on paper [Tricard et al., 2019]. A branching structure is generated that gets progressively denser towards the top surfaces to support them reliably. Like the Arachne perimeter generator, we have ported the Lightning infill from Cura, thanks again for keeping Cura open source.
Pressure equalizer:
FDM printer consists of a motion system and an extrusion system. While the motion system loves to accelerate and decelerate smoothly to reduce vibrations, the extruder loves to extrude at a constant rate for best extrusion consistency. Unfortunately the optimal conditions of the motion system and extruder are contradictory. Bowden style extruders are especially sensitive to pressure fluctuations, due to the slack in bowden tube they are not able to reproduce rapid changes in extrusion rate reliably.
With bowden style extruders, moving from internal perimeter printed at high speed to external perimeter printed at slower speed the extruder often produces a bulge at the start of the external perimeter due to an excess extruder pressure. Similarly when moving from external perimeter to infill the extruder produces gap at the start of infill because of the extruder pressure deficit. To lessen these artifacts caused by rapid extruder pressure fluctuations, we have implemented an experimental "Pressure equalizer" feature.
Before moving from faster internal perimeter to slower external perimeter, the pressure equalizer slows down gradually the end of the internal perimeter to reach the extrusion rate of the external perimeter. Similarly when moving from the external perimeter to infill, the start of the infill is slowed down to external perimeter speed and accelerated gradually. The volumetric rate fluctuations are configured at Print Settings->Speed->Pressure equalizer, they are limited by the new Max volumetric slope negative and Max volumetric slope positive configuration values. Slowing down infill after perimeter may increase print times excessively, thus it could be suppressed by setting Max volumetric slope positive to zero.
Visibility-based seam placement:
Starting with this version, seam placement algorithm prefers regions which are not visible from the outside of the model at all or which are occluded from most directions. The new visibility algorithm is applied for seams set to Nearest or Aligned.
Other improvements:
G-Code thumbnails can now be exported in JPG and QOI formats (until now, only PNG thumbnails were supported). This should make it possible to see the thumbnails on printers which do not support PNG thumbnails. Namely the Duet boards with RepRapFirmware are low on RAM to decode PNGs, but they happily consume QOI thumbnails. Thanks to @n8bot for initial implementation.
SLA hollowing was optimized and it is now significantly faster. The actual speed-up depends on the model, but in general it is several times faster. The difference is especially noticeable on bigger models, where it can be 10x faster than before.
SLA time estimate was improved and it is now more accurate for SL1S. In addition, "High viscosity tilt time" was added into Printer Settings so the time estimate is correct for printers supporting separate tilt time setting for high-viscosity SLA materials. #8421
Concentric infill is newly properly filled by the new Arachne perimeter generator if Arachne is enabled. #577, #1461, #3104
Bugfixes:
OSX specific: It is now possible to send G-Codes to OctoPrint using self-signed certificates. The OSX system SSL library does not accept self signed certificate, however OpenSSL based libcurl library shipped with OSX does. See also the following Prusa3D forum thread and #5984
Fixed a crash when using a selection rectangle with the cut gizmo open.
Fixed a memory leak during slicing e0e34f6.
Windows specific: Dialog asking to send system info shown at startup no longer pops up in case the internet connection is not available.
Fixed a crash when using auto-rotation with some specific models #8319.
When using arrange in sequential printing mode, it sometimes tightly violated desired extruder clearance #8335.
Fixed flickering of colored rectangles in legend in the stand-alone G-Code Viewer.
When using wipe tower with no sparse layers, the first layer might have ended up too thin and ruined the print #7090, #8358.
OSX specific: Cmd+M shortcut should now minimize the application as expected, restoring the application using the "View All Windows" works. #6364, #8352
When clicking the "Detach from system preset" button in Dependencies section of a profile, the button did not disappear. Also, detaching a printer profile from a system profile broke rendering of custom bed model for both the parent and child profile. Both issues are fixed now.
Fixed a very rare issue which led to generating a G-Code with commas instead of decimal points (caused by incorrectly set locales on one of the threads).
Windows specific: Improved detection of corrupted PrusaSlicer.ini configuration file. Very rarely for some unknown reason PrusaSlicer.ini is partially or fully filled in with binary zeros, most likely due to power outage or a bug in hard drive driver #8217.
OSX specific: When trying to open a G-Code file using drag and drop or "Open with" option, G-Code Viewer would report the file extension as unknown when PrusaSlicer was not already running #8300, #8344
Filament usage estimate was incorrect when using MMU. The loading and unloading moves were not correctly accounted for, leading to much higher estimate then reality. Only the 'Sliced Info' box was affected, the statistics at the end of the G-Code were correct.
Fixed a crash when rescaling the windows or changing color mode (Windows, OSX). This should fix some spurious crashes happening when moving PrusaSlicer window between two monitors etc.
Fixed inadvertent deselection after changing and confirming object-specific settings #8342
Changing object-specific settings incorrectly inserted two undo/redo snapshots.
Some configuration options always showed as modified in profiles inherited from the ---default--- profile.
Fixed a crash when pressing Ctrl+A while using a painter tool or editing SLA support points or drainage holes #8416
Linux specific: Fixed a crash when confirming a value in Height range modifier #7531, #8055, #8408

New in Prusa Slicer 2.4.2 (May 1, 2022)

New in Prusa Slicer 2.4.2 RC 2 (Apr 13, 2022)

New in Prusa Slicer 2.4.2 RC 1 (Apr 5, 2022)

New in Prusa Slicer 2.4.1 (Apr 5, 2022)

New in Prusa Slicer 2.4.1 Beta 3 (Feb 24, 2022)

New in Prusa Slicer 2.4.1 Beta 1 (Feb 1, 2022)

Improvements with respect to 2.4.0:
G-Code substitutions:
PrusaSlicer supports processing of the generated G-code with an external post-processor for a long time. Launching an external post-processor is versatile, however it is complex to setup, the post-processing scripts must be distributed with the project and the interpreter running the post-processing script (for example Python) has to be available. We collected many real world use-cases for the post-processing scripts and concluded that many of them could be covered by a simple "Find and Replace" tool with regular expression matching and substitutions.
To make life easier for everyone who only needs basic post-processing, we now integrated such a tool directly into PrusaSlicer. It is accessible from Print Settings -> Output options and allows to add a number of find and replace pairs, with optional regex matching, case sensitivity and whole word matching, similar to what common text editors offer. The G-Code is processed before it is previewed, so your changes will be visible in the G-Code preview.
We hope this tool will make common post-processing tasks simpler, such as adding custom annotations, adjustments of output format such as in #6996), ringing cancellation, adjustments of per feature extrusion rate and similar.
Regular expression syntax of Perl is supported as described in boost Perl regular expression syntax, where a "single line" modifier mimics the Perl's s/ modifier. With regular expressions active, the "Replace with" pattern supports the "extended" syntax as described in boost extended format syntax. Lookahead and lookbehind are supported by the regular expression engine, but only for fixed length patterns. With regular expression disabled, n, r, t, and \ placeholders are supported in both "Find" and "Replace with" patterns similarly to Notepad++'s "extended" syntax.
The G-code find/replace post-processor processes G-code in blocks, where a single G-code block is generated for each layer starting with the Z up to move to the next layer. Multiple find/replace patterns are applied one by one to one G-code block before processing the next G-code block. Matching multi-line patterns is possible, however only inside one G-code block, most likely inside a single layer. Regular expressions are powerful but tricky, thus we recommend the regular expressions 101 online playground to get familiar with regular expressions and to test and fine tune the regular expressions modifying G-code before entering them into PrusaSlicer. Don't forget to switch the regex flavor to ECMAScript in the regular expressions 101 online playground.
An example of a quite powerful G-code modification by a reasonably complex regular expression: Increase the extrusion rate of top solid infill from the default 95 percent to 98 percent.
Find: (;TYPE:Top solid infilln)(.*?)(;TYPE:|$)(?!Top solid infill)
Replace with: ${1}M221 S98n${2}M221 S95n${3}
Modifiers: regexp, single line
Other improvements:
Seam placement was improved. In 2.4.0, seams on internal perimeters were placed close to external seams to reduce long travels between seams, with additional staggering of internal seams wrt. to the external seams, so that they do not overlap. This sometimes produced an internal seam on a straight perimeter segment, even thought there was a convenient corner nearby, producing a visible bulge on the outer surface. The internal seams are now placed close to the external seam, but not at all costs. The staggering is now disabled as it often produced unnecessary jerking of the printer. Also, there was a bug in the seam placement algorithm, which again caused excessive travels in some cases #7690 #7686 #7784.
In Spiral Vase mode, the G-code viewer used to assign a layer to each G-code segment of a spiral producing an excessive number of layers thus making G-code inspection difficult. The G-code viewer newly assigns a layer to a single spiral turn #4440.
A new option "Ask for unsaved changes in project" was added into Preferences to control whether the user shall be asked to save a project on closing an application or when loading a different project. The existing three options "Ask for unsaved changes when..." always referred to the changes in presets, thus they are now reworded to make it clear #7114.
Machine limits table in Printer Settings is now available for RepRapFirmware, while until now it was only enabled for Marlin #7347 thanks @n8bot.
Implemented new placeholders for output file name:
initial_filament_type and printing_filament_types (useful for multi-material prints) #5300, #7684, #7673
initial_tool and initial_extruder - zero based index of first extruder
num_printing_extruders - number of printing extruders.
New option "Restore window position on start" was added to Preferences. We have received reports of rare crashes on application start-up when trying to restore application main window position on some multi-display setups. While we were not able to fix the crash, we newly detect a crash during the window position restore and we suggest to disable the window restore option on the next application startup as a workaround #2939, #5573.
Windows specific: The build_win.bat script newly supports a low CPU priority compilation option #7828 thanks @Jebtrix.
FDM printer firmware usually keeps an absolute extruder axis position using a single precision float representation, which leads to a loss of accuracy if the extruder axis is not resetted regularly. In extruder absolute mode 'G92 E0 is issued at each retraction by PrusaSlicer, while in extruder relative mode it is newly enforced, that either layer_gcode or before_layer_gcode contains 'G92 E0'. On the other side, in extruder absolute mode, 'G92 E0' in layer change custom G-code breaks slicer's assumption leading to horrible over-extrusions, thus 'G92 E0' is newly tested for and prohibited with extruder absolute addressing #6336 #5073.
Bugs fixed:
Windows specific: Fixed crash on some machines at the very start of the application. The bug was introduced to PrusaSlicer 2.4.0-beta1 with the dark mode support #7560 #7574 #7613.
Windows specific: Dark mode is now enabled for all the new Windows builds. Let's hope that Microsoft will maintain the undocumented API that PrusaSlicer and other applications rely upon #7546.
Fixed a rare crash in Configuration Wizard under certain conditions, mainly on OSX #7655.
'Place on face' function was very slow when used on some complex models #7587.
When 'Reload from disk' attempts to load an invalid file, an error message is newly shown, while previously the error was silently ignored #7550.
'Export to STL' did not work for individual parts and modifiers, the option was grayed out. This was a regression wrt. PrusaSlicer 2.3.3 #7647.
Windows specific: Button in focus and the default button was not highlighted. The issue was introduced with the dark mode support in PrusaSlicer 2.4.0-beta1. Because of missing Win32 dark mode support for buttons, we had to resort to flat rendering of buttons. However with flat rendering, Win32 buttons do not support highlight of a default or active button and we had to implement a workaround ourselves #7564.
Cancelling "Fix by NetFabb" might have left a temp file opened. This is now fixed #7632.
Windows specific: Fixed color of the text in Firmware updater window when firmware flashing is done.
Fixed crash during slicing when a negative volume was used on painted areas of a multi-material model #7618.
Fixed mangled text in "did you know" notifications when breaking a long line at a non-ASCII character #7611, thanks @odaki.
Fixed crash on closing the application on OSX Sierra and older #7583.
SLA pad model was sometimes not generated correctly, which was visible during preview visualization.
Removed empty G1 command which appeared before bridging perimeters were printed #7714
Fixed some text encoding issues in Print host queue dialog.
The "Unsaved Changes dialog" used to inform that some of the differing keys are too long to be displayed fully and that one may open a pop-up window to show the full content of the differing keys. This was broken in 2.4.0 and it works again now #7734.
Avoid crossing perimeters was improved in PrusaSlicer 2.4.0 to not move along the outermost perimeters. This feature did not work reliably for thin islands, which should be now improved #7699.
The Yes/No/OK/Cancel buttons on various dialogs were displayed using the system language and not translated to the language set in PrusaSlicer. This is now fixed by providing dictionaries for these buttons #7542.
Fixed possible crash during print host upload, likely related to #7681.
The G-Code Preview parser did not skip whitespaces between axis letter and number, so e.g. G1 X 10 would not be correctly displayed in Preview. This was a bug introduced in PrusaSlicer 2.4.0 due to G-code export speed-up #7773.
Some excessively wide message boxes were sometimes shown for example when showing a very long file path. The texts in message boxes are newly wrapped to keep the width of these message boxes reasonable.
When printing with a single extruder only with a multi-material printer profile active while the printing extruder was not the default one, the G-code viewer did incorrectly considered the printer to not support multi-material printing, thus the cog icon below the vertical slider did not offer the 'Set extruder sequence' option. This is now fixed.
When the type of an object part was changed from a printable part to a modifier, the part should be rendered transparent, but the transparency was not updated immediately.
Cut tool sometimes showed the cut contours incorrectly after object parts were added and removed.
Fixed crash when editing thumbnails in Printer settings #7781.
Fixed an incorrect invalidation of PrusaSlicer configuration in case old PrusaSlicer is started, which reports that it does not support the current configuration thus it proposes to downgrade configuration to a version it understands. In case the user refuses to downgrade, the configuration was incorrectly marked as downgraded #7780.
OSX specific: "Did you know hints" referencing Cmd-F hot key will now show Cmd-F, not Ctrl-F #7820.
Localization:
Added Catalan localization #7566 thanks @davidjuanesb.
Updated CZ, PL, IT, ES, DE, FR translations (including previously not translated phrases and typo fixes)
Added Hungarian localization #5479 thanks @zormatt.

New in Prusa Slicer 2.4.0 (Dec 27, 2021)

New in Prusa Slicer 2.4.0 RC 2 (Dec 17, 2021)

New in Prusa Slicer 2.4.0 RC (Dec 15, 2021)

New in Prusa Slicer 2.4.0 Beta 4 (Dec 11, 2021)

Improvements with respect to PrusaSlicer 2.4.0-beta3:
Windows specific: "Dark mode" option now shows in Preferences even in standalone G-Code Viewer.
Optimization of G-Code rendering, which improves speed issues mentioned in #7415, for example of the volumetric speed preview.
When an existing configuration folder is found on application startup (for example configuration saved by PrusaSlicer alfa was found by PrusaSlicer beta), an extra dialog to decide whether its contents should be copied to active configuration directory was added to 2.4.0-beta2. The text in the dialog was now rephrased to be more clear. The existing configuration check is also no more performed when PrusaSlicer is started with a custom configuration folder set by the --datadir command line argument.
Automatic random colors generated for color changes were slightly adjusted to avoid generation of extremely light or dark colors.
We newly provide both GTK2 and GTK3 builds for aarch64 (64bit operating systems on Raspberry PI, Linux on Chromebooks). We provide both binary builds and AppImages, thanks @davidk for showing the way.
We newly provide an AppImage for armhf (32bit operating systems on Raspberry PI) in addition to the binary .tar.bz2 distribution.
Bugs fixed:
Windows specific: Fixed resource leak that manifested by UI controls corruption and spurious crashes after application ran for a long time and parameter tabs were switched many times #7369.
Fixed label on the new 'Upload and Simulate' button added in beta3 for Duet print host #7424.
Windows specific, broken in beta3: With settings opened in their own non-modal window, a modal dialog opened from the settings window incorrectly opened over the main window, stealing focus from the settings window after the modal dialog was closed. This is now fixed #7419.
Fixed a crash of the stand-alone G-code viewer when opening application preferences #7430.
Fixed a crash in G-code preview with some OpenGL drivers #7415.
Since PrusaSlicer 2.4.0-alpha1, first layer height could no more be specified as a percentage of a layer height. When loading an old profile, the first layer height is being properly converted to an absolute value when loaded, but the user interface still allowed the percentage to be entered. A check was newly added disallowing a percentage to be entered #7418.
The dialog suggesting to enable 'Detect bridging perimeters' when supports are enabled kept appearing in an infinite loop under certain circumstances #7419.
Fixed robustness issues manifested with spurious infills after re-slicing #7442.
Fixed 'Rear' seam option, which was not always respected. This is a regression since PrusaSlicer 2.4.0-alpah1, which started to manifest after recent seam improvements.
Fixed sliders in SLA gizmos, broken in beta2 after the 'Edit' button was added. Changing of support points diameter, hole parameters etc. was not possible for existing holes.
Fixed reverting of a spiral vase mode setting with the "undo" button at the top of the Print settings page. Resetting configuration page to previous state using the undo button lead to a spurious dialog to change other settings in order to use spiral vase mode being shown #7146.
OSX and Linux specific: Some of the modal dialogs with Yes and No buttons incorrectly interpreted Esc key as Yes.
Fixed performance issues with "infill only where needed" enabled #1696 #6385.
Windows specific: Fixed rare layout issues resulting in some of the combo boxes being rendered too small #7414, #7176.
Fixed 'Reload from disk' which did not work for modifier volumes and which sometimes shifted the reloaded object incorrectly #7429.
Fixed solid infill of all layers achieved by setting solid_infill_every_layers to 1. With ensure_vertical_wall_thickness disabled many layers were not filled at all, with ensure_vertical_wall_thickness enabled the layers were incorrectly filled with bridging infill #6736.
Fixed regression in FDM supports, were the support interface at first layer overlapped with expanded support base #7460.
Improved robustness of "don't support bridges" for bridging perimeters #7260.

New in Prusa Slicer 2.4.0 Beta 3 (Dec 5, 2021)

Improvements with respect to PrusaSlicer 2.4.0-beta2:
MKS WiFi print host is newly supported #5617, thanks @RandoMan70.
Duet WiFi print host newly allows to initiate a print simulation in addition to initiating an actual print #5157, thanks @mloidl.
Since 2.4.0-alpha1, post-processing scripts are run on a temporary G-code file before the post-processed G-code is copied to the final destination or sent to a print host. The post processing thus has to be done in-place and it must neither rename nor move the file, which was always required by the manual. In this release, this requirement is explicitly mentioned above the post-processing script input field and a more descriptive error message is shown in case the temporary G-code file is deleted or renamed by the post-processing script. See the respective Prusa Knowledge Base article for details and how the script may pass a new G-code name to PrusaSlicer if needed.
New config value "gcode_resolution" was added to control maximum deviation of the exported G-Code from the full resolution toolpaths. Very high resolution G-Code requires huge amount of RAM to slice and preview and a 3D printer may stutter not being able to process a high resolution G-code in a timely manner. On the other hand, a low resolution G-code will produce a low poly effect and because the G-code reduction is performed at each layer independently, visible artifacts may be produced. The G-code resolution defaults to 0.0125 mm, while modern 32 bit printer control boards are able to process G-code with about twice the resolution (0.005mm) with no issue.
The painting tools (paint-on supports and seam, multi-material painting) newly produce smoother regions. When mouse is moved quickly, the active spherical or circular cursor used to be applied at mouse positions only producing jagged edges, while newly the path traveled by the mouse is interpolated with cylinders producing smooth smooth boundaries.
Several icons in menu (Shape gallery) and object list (Sinking, Paint-on supports/seam/multimaterial) icons were added or updated.
Localization:
Dictionaries for CZ, DE, ES, FR, IT and PL were updated by Prusa Research. Contributors are welcome, please check the localization guide.
Bugs fixed:
Count of custom G-Code lines shown at the vertical slider is limited to avoid tooltip flickering when the tooltip text is too long #7368.
'Slice resolution' parameter was not taken into account in previous 2.4.0 prerelease versions #7364.
Fixed a bug resulting in support material interface pattern "Rectilinear Grid" value being reported as unknown #7316, thanks @n8bot.
OSX specific: Fixed saving of G-codes with a custom file extension. When opening a "Save" file dialog with an output file name generated from the output file template, OSX file dialog strips the provided custom file extension and replaces it with the default file extension. This causes issues with a custom file output template, where a non-default file extension is specified. This was now improved and when a custom extension is provided by the output file name template, it is passed to the file dialog as the first extension in the list of file extensions supported, thus the custom file extension becomes the defaut #7190.
Handling multi-part objects with "clip_multipart_objects" disabled was broken in all preceding 2.4.0 alphas and betas, which resulted in some object parts not being printed at all. This is now fixed and with "clip_multipart_objects" disabled, individual parts are printed overlapping #7366.
Windows specific: "Use system menu for application" option in Preferences is newly suppressed for systems older then Windows 10. PrusaSlicer 2.4.0-beta2 did not start on Windows 7 because a Windows 10 only API was called #7355.
Fixed a possible crash when deleting objects while 'Arrange' or 'Optimize orientation' was in progress.
'Arrange' and 'Optimize orientation' can no longer be executed simultaneously, one waits for the other to finish.
"Height range Modifier" menu item is no more available in 'Simple' mode #7381.
Windows specific: Text controls in settings tabs (for Custom G-Codes etc.) now correctly handle encoding. Non-ASCII characters were previously mangled on Windows #7384.
Linux specific: Avoid crashing with DISPLAY environment variable not set, just show a warning and print out a help screen.
When sending system info from the recently introduced dialog and sending the system info fails, the "sent" flag is newly not saved, ensuring that the user is asked another time during following application start-up.
When raft was enabled, visualization of objects' shells were not elevated above the raft in G-Code preview #7388.
Fixed a bug when 'disable fan for first N layers' was not respected with raft enabled. The cooling logic was broken for raft during recent refactoring to cool support layers together with the object layers they support #7232.
Windows only: Increased robustness of convex hull calculation by switching from floats to doubles. On other platforms the convex hull calculation was already using doubles. The insufficient convex hull robustness caused issues for some degenerate objects created for example by the cut tool #7377.
"Did you know" notifications showed in English, even when the translations into a local language were available.
Fixed some crashes in G-Code preview with specific models #7396.
Avoid crossing perimeters did not work correctly when 'Detect thin walls' or 'External perimeters first' options were enabled #7209.
Windows specific, OctoPrint support: Beta2 introduced a workaround for mDNS discovery, however the workaround broke support for complex host URLs, for example with non-default host port specified. This is now fixed #7361 #7389.
Fixed incorrect rotation when volumes are being rotated by the gizmo while Alt key is pressed. This is a very old bug already present in 2.0.0.
Object labels showing sequential print order were sometimes shown when the respective menu item checkbox was unchecked #7207.
Fixed an issue with ironing, which was applied multiple times in case a part of the ironed top solid infill was inside a modifier mesh.
Fixed crash when trying to delete the last printable volume of an object #7408.
Windows specific, if installed by the Prusa3D Drivers installation package: The "Drivers" installer installs a 3rd party updater. The "Drivers" package used to install a "PrusaSlicer" link, which pointed to a 3rd party installer, which in turn launched PrusaSlicer. Unfortunately this broke launching PrusaSlicer by drag & dropping STLs and 3MFs onto the PrusaSlicer icon #6769. This is now fixed by PrusaSlicer launching the 3rd party updater, not vice versa. The 3rd party updater is only launched by PrusaSlicer if 'Check for application updates' is checked in Preferences. This overrides settings the 3rd party updater itself, meaning it will not be started even if set to check for updates e.g. every week.
Windows specific: Fixed zooming with a touch pad on some Windows laptops. This is an old issue which was fixed long time ago, then broken again in PrusaSlicer 2.3.0 #2750.
Linux specific: Fixed focus issue with some window managers with "focus follows mouse" enabled #5620 #6870.

New in Prusa Slicer 2.4.0 Beta 2 (Nov 27, 2021)

Windows dark mode improvements:
As mentioned in beta1 change log, we continued in Windows dark mode implementation. This was a tedious work given the lack of support provided by Windows API, but we managed to skin most widgets and got reasonably nice look on both Windows 10 and 11 in the end.
Main improvements with respect to 2.4.0-beta1 are included in prusa3d/wxWidgets@4b7588e:
Skinned title bar for most dialogs and frames
Redrawn Spin controls
Skinned tooltips, scroll bars, menus, and list boxes
We also improved dark mode version of "Change volume type" dialog and PrintHost dialogs.
Other improvements with respect to PrusaSlicer 2.4.0-beta1:
When copying system info from About->System Info dialog into clipboard, OpenGL extensions are newly enclosed in <details> tag so they are wrapped when inserted into a github issue #6830
Conversion from inches/meters to mm can now be done for all loaded objects at once, so the user does not have to confirm each object separately.
New functions in custom G-Code macro language: round(value) (rounds to integer), digits(value, num_digits, num_decimals) (rounds to num_digits and num_decimals, left filled with spaces), zdigits(value, num_digits, num_decimals) (same as digits(...), only left filled with zeros) #3472
New placeholder parser values for output file name template: {num_objects} (number of printable objects on the plater), {num_instances} (number of all printable instances on the plater) #2735 #3339 #4607
When selecting SLA support points by the selection rectangle, even points that are slightly obscured by the object are selected. Until now, the center of the visualized sphere had to be visible, and it sometimes hid behind even very tiny bumps on the object.
When running 32-bit build of PrusaSlicer on 64-bit operating system, the user is instructed to download the correct version. While such application will run, it will be slower and will easily exhaust memory.
Fixed a crash when uploading G-Code to a print host for the second time #7170
When PrusaSlicer detects there is a more recent configuration folder than the one it is about to use (such as an alpha/beta specific folder), the user is asked if he/she wants to copy that configuration into the current folder. A configuration snapshot is taken in case there is something that would be overwritten.
Added a "Start printing after upload" checkbox for Repetier server (#5351, thanks @scott0122)
Sliders presented in the in-scene dialogs always allowed to type in the required value after Ctrl+mouse click. Because this useful feature was too hidden, we now show a small button to the right of each slider to switch it into this mode
SLA material color can now be specified in Material Settings. The color is used for visualization in the scene and is also shown in the right panel combo box. Until now, the last FDM filament color was used.
Windows specific: When PrusaSlicer was downloaded from the Drivers bundle and installed using the installer, the created desktop shortcut launched external updater application instead of PrusaSlicer. The updater checked updates online, notified the user when a newer version was found and then started PrusaSlicer. The drawback was that command-line arguments were not correctly passed. This was now improved by switching the order: PrusaSlicer now runs the updater after it starts. This only happens when 'Check for application updates' is checked in Preferences and the built-in notification about the same thing is supressed in that case.
In-scene dialog widgets now accept Numpad Enter (until now, only Enter was accepted)
Shape Gallery dialog can now be closed by pressing Esc
Linux specific: Extruder colors in the right panel can be changed by clicking the cog wheel to the right of the respective filament preset #6759
When uploading G-Code to print host, the confirmation dialog now has an "Upload and Print" button (instead of a checkbox)
Changing purge volumes in multi material project did not mark project as unsaved #7265
Minimum diameter of the brush in the multi-material painting gizmo was reduced to 0.1 mm #7108
Configuration Wizard: when adding a printer profile with no default filament/material profile, the dialog is shown informing the user that one should be selected manually
When custom extrusion visibility is supressed in Preview, they are not taken into account when 'Volumetric Flow' view is shown. The scaling of the color palette is therefore more appropriate #7066
Context menu in the right panel now shows even when right clicking the name of the respective part, not just the 'Editing' column #7270
SLA material expansion correction can now be set independently for all three axes
Increased translation speed maximum in 3D connexion dialog to 30 (#3385)
'Scale to print volume' now works with circular beds
When color changes are added using the vertical slider in Preview, the colors are newly chosen randomly. Until now, a fixed predefined sequence of colors was used, leading to issues when the color changes were not added in order).
Out-of-bed detection was refactored and is now faster
Support generator now merges bottom contacts, top contacts and interface layers where possible (always possible with soluble supports, with non-soluble supports it is only possible when they are extruded without bridging and have the same layer height). This removes thin loops of interfaces that were sometimes generated with complex geometries and should generally result it nicer support interfaces.
Added experimental filtering of propagated support columns to two extrusions, overlapping by maximum 20%. This filtering step will remove spurious columns that do not support anything, but it may also remove supports supporting tiny islands (which would likely not be printable anyway without user intervention, such as extending the supported area by painting).
Bugs fixed:
Mirrored objects appeared darker in multi-material painting mode (except on macOS Monterey, where non-mirrored objects were darker). The issue is now solved on all platforms and operating system versions #7259
Multi-material painting did not correctly propagate top and bottom solid layers on mirrored objects
Fixed a crash in bed collision detection when there were sinking toolpaths
Fixed calculation of estimated times for individual layers for multi-material models #7110
Variable layer height editing did not not work when printing on raft (broken between 2.3.3 and 2.4.0-alpha1) #6999
Fixed an ugly artifact sometimes appearing in Configuration Wizard (incorrectly shifted printer images)
When supports are enabled and 'detect bridging perimeters' is disabled, a suggestion appears to turn it on. This suggestion newly only appears when the user makes the change, not when such config is loaded #6814
Bottom layer of a multi-material painted model had incorrect color when the object was partially below the bed. This is now fixed #7107
'G-code thumbnails' config option now accepts an empty string to turn thumbnails off #7019
Fix of a crash when layer count exceeded 4095 in slicing code and MMU segmentation, likely specific to fine layered SLA prints #7168
Fixed a crash when a part of a multipart object is completely below the printbed
Fixed a possible problem in SLA mode: supports inside cavities might have ended up not attached to the model
When selecting an object while moving the mouse, only one part was sometimes selected #7160
Fixed missing sinking property in objects list for multipart objects with some parts completely below the printbed
Fixed incorrect handling of exactly horizontal surfaces that were painted (by supports/seam/multi-material). The painting was sometimes ignored.
Fixed int() function in the macro language: it did not accept an expression unless it was enclosed in double parentheses. Constants and variables were processed correctly #3472
Fixed localization encoding issues in Undo/Redo stack (introduced in 2.4.0-alpha3)
Clipping plane in gizmos was not shown correctly when viewed exactly from Left or Right #7211
Reworked an internet connection check before the new 'Send system info' is shown. The check sometimes did not work and the application was unresponsive before it timed out. It is now done differently (hopefully more reliably) and only on Windows. Linux and macOS open the dialog even without internet connection.
Fixed high CPU usage and nonresponsive application during parameter changes for objects with a large number of modifiers #7220
Brims were sometimes not generated in 2.4.0-beta1 (all objects missed inner brims, objects inside holes of other objects missed the outer brims too) #7213
Empty G1 commands were sometimes present in the G-Code due to the cooling slow down logic. This is an old bug present in 2.1.0 already #3058 #5176
Default color sometimes appeared at the boundary of two multi-material painted areas #7112
Fixed a crash after a filament or SLA material was installed with a Configuration Wizard and then erroneously activated even though it was not compatible with the active printer profile #7169.
SL1 files produced by very old PrusaSlicer versions did not contain the used profile. When loading such a file, layer height to use is loaded from config.ini instead (it should always be part of the SL1 archive).
The settings in 'Import SLA archive' dialog now retain the selected value, so the users don't have to reselect them every time they open the dialog
Mesh errors after SLA import are now repaired (as they were in 2.3.3, but not in 2.4.0-beta1). This is a consequence of recent refactoring related to admesh library.
Fixed dimples in external perimeter after slicing multi-material painted model #7235
Fixed crash in the multi-material segmentation when some projected triangle is outside the bounding box of the current layer #7299
Fixed bulges of base color on multi-material painted models #7109
Fixed a beta1 crash after typing zero into scale or size fields in the right panel #7245
Fixed cut function that sometimes worked incorrectly when applied on multi-part object #7258
Fixed error when resizing object to bed limit (may be exactly equal to the build volume height) #7246
Fixed a crash after splitting object into parts #7282
Fixed a crash when simplifying a mesh and manipulating Undo/Redo after it
Simplification preview does not mark project as modified, invalidate slicing, insert Undo step nor remove painted areas
A warning about empty layers is newly emitted once per object, even when there are multiple empty layers detected
Fixed 'Volume' in the Info box in the right panel. It showed incorrect values when the selected volume was scaled and non-sense value when multi-instances object was selected. The Info box is now shown only when a single volume is selected.
Fixed a crash during slicing in SLA mode (localization dependent, present e.g in German) #7313
Fixed infinite loop of dialogs suggesting to enable wipe tower layer synchronization in some cases #6124
Empty layer warning sometimes reported false positives (broken after support top/bottom distance was separated) #6709
Simplify dialog no longer obscures the main toolbar when opened after undo/redo
When attempting to simplify a multipart object, user is newly informed that it is not supported (beta1 did not do anything)
SLA hollowing preview sometimes did not show correctly when it was toggled on and off again
Fixed a crash when entering negative values in sliders in variable layer height dialog (the range can be overriden with Ctrl+click)
Horizontal slider in Preview sometimes (after a specific sequence of actions) incorrectly iterated over two layers, not one as it should
Spiral vase mode was not applied when 'complete individual objects' was also active
Windows specific: OctoPrint did not work when using hostname instead of an IP address. This should now be fixed.
Linux, macOS: When exporting GCode, characters that are invalid on Windows are not allowed in the filename. They led to crashes when exporting to FAT/NTFS formatted drives.
Support generator: "with sheath" option now again uses the lighweight zig-zag algorithm for the sparse support columns, while PrusaSlicer 2.4.0-alpha1 to PrusaSlicer 2.4.0-beta1 used the new "stable" zig-zag algorithm for both the non-sheathed and sheathed sparse support columns creating unnecessarily thick support column perimeters.
Fixed endless loop of "Do you want to save the project?" possibility in a specific scenario
Translations, profiles:
Updated CZ translation
Fixed a mistake in Korean translation (#7164, thanks @tangible-idea)
Fixed several typos in UI texts (such as #7161)
Added Ultimaker 2 printer profile (thanks @foreachthing)
Added several Voron printer profiles (based on the profiles from https://github.com/slic3r/slic3r-profiles, thanks to the original authors)
Updated BASF filament profiles

New in Prusa Slicer 2.4.0-beta1 (Oct 26, 2021)

FDM support improvements with respect to PrusaSlicer 2.4.0-alpha3:
Disabled enhancement of thin long overhangs to be supported. The enhancement produced supports at object corners, which were difficult to explain #3094.
Disabled filtering step that removed support towers in case the support contact island supporting an overhang was completely trimmed by the support / object XY separation distance. Such filtering made sense to reduce excessive supports before introduction of support blockers and paint-on supports, however the filtering step was the reason of PrusaSlicer support generator seemingly not respecting the support overhang threshold and support enforcers #1324.
Fixed missing interface layers for snug supports by propagating full overhangs before trimming by the support / object XY separation distance when generating interface layers. This change together with the previous topic significantly improves #6058 #6902.
Rounding / merging of snug supports using the closing radius parameter is now smoother, it does not produce sharp corners.
When calculating snug support interfaces below support contacts, the projected support contact areas are expanded to produce wider, printable and more stable interfaces. This fixes some missing snug support interfaces.
For grid supports, supports supporting steep overhangs are not covered with dense support interfaces, because steep overhangs are mostly self supporting. However this strategy did not work well for the snug supports with narrow towers, thus overhangs with all angles are newly covered with support interfaces #6331.
For snug supports the interface layers are newly angled at 45 degrees from the base supports and they alternate their direction by 90 degrees, making the interfaces cohesive.
Fixed planning of support interface layers with rafts and larger Z gap for supports than for the raft.
Regression to PrusaSlicer 2.4.0-alpha1: Some of the support interfaces were not supported by the sparse support again #7014.
Fixed soluble interface support interfaces / non soluble base for support enforcers, where base support was supporting an object without interface layers #2849.
Improvements of painting gizmos:
'Smart fill' and 'Pointer' brush types introduced recently into multi material painting gizmo are now available at FDM support and Seam painting gizmos as well.
The FDM paint-on supports gizmo newly allows limiting the brush strokes to triangles highlighted by "Highlight by angle" slider. One may let PrusaSlicer highlight the overhangs and one can quickly mark only those highlighted areas that are essential to the success of the print while masking out the non-overhang areas.
With clipping plane enabled, the areas clipped by the clipping plane are no more painted.
Seam improvements:
When possible, PrusaSlicer newly places seams on internal perimeters close to external seams, reducing travel moves and retractions. For leaky extruders, bowden setups and leaky materials (PET, PVA) reducing travel between perimeters reduces gaps at their starts. The seams between the nested perimeters are not aligned exactly, but they are staggered by a short distance to reduce bulge of the outer most seam #6790, #6400, #6741, #6494, #6186, #5149.
Other improvements with respect to PrusaSlicer 2.4.0-alpha3:
Circular print beds are newly fully supported: Objects pulled out of circular print beds turn blue and print paths outside of a circular bed are detected. Convex print beds are partially supported: The part of an object outside of the print bed volume is not yet highlighted with blue color. No collision detection is performed for non-convex print beds #5388 #6460.
Notifications about new PrusaSlicer versions available for download are newly available for prerelease versions (alphas and betas) as well. Notifications on new alphas and betas can be enabled / disabled in Preferences.
Several more improvements regarding notifications (new icons, adjusted timeouts, minimal time notification stays on screen, no focus on hover).
Windows specific: After a model is repaired by Netfabb successfully, a notification is shown instead of a modal dialog #7067.
Modifiers, support blockers and support enforcers are newly rendered transparent #7076.
The mesh simplification tool newly initiates calculation of the preview of the simplified model automatically, the "calculate preview" button is gone. The calculation can be stopped by pressing Esc key.
PrusaSlicer highlights toolbar items and print preset options with red blinking arrows after they are selected by the search dialog or when clicking on a hyperlink of a "Tip of the day" notification. The red blinking arrow is newly newly supported by the Preferences dialog as well. For example, clicking the "cog wheel" icon of the "Tip of the day" notification opens the Preferences dialog and a red arrow blinks next to the "enable / disable tip of the day" checkbox.
Models with zero volume (for example an STL with one polygon) are no more loaded. Previous versions of PrusaSlicer loaded such files, but these objects did not show on Plater, which was confusing.
Reporting of repaired and / or corrupted models has been improved. PrusaSlicer newly distinguishes between three states: 1) Model is fine, 2) model was broken, but it is now fixed, 3) model is still broken. The three states are reflected by the "warning" icon at the side panel: If the model is still broken, red "exclamation" icon is shown. If a mesh was broken but repaired successfully, white "warning" icon is shown.
If a mesh was repaired during import into PrusaSlicer, the number of errors fixed is newly saved into 3MF, so that the status of an imported model is not lost.
New default shapes were added into the Shape Gallery.
Context menu is newly available for custom shapes of the Shape Gallery, which allows to delete a custom shape or to modify its thumbnail. The dialog also newly accepts the Del key.
Windows 11 specific: Fixed implicit setting of the dark mode.
Travel paths planned by the "avoid crossing perimeters" algorithm no more follow the outermost perimeter, but the 2nd outermost perimeter if possible. This should improve the print surface quality and reduce re-heating of overhangs.
Hollowing gizmo newly allows drilling larger holes for inserting magnets #6101
"Copy to clipboard" at the "System info" dialog newly encloses the lengthy OpenGL extensions details into a <details> tag, thus helping to make the github issues easier to read #6830.
Bugs fixed:
Fixed dimples sometimes appearing on multi-material painted objects, often happening on cylindrical objects #7104.
Improved detection of seams and their visualization by the G-code viewer. Some of the seam points were missed #6895.
Fixed incorrect default context menu if the right mouse button was clicked on empty space in 3D scene when several objects were selected.
Fixed some issues due to the recent admesh eradication in PrusaSlicer 2.4.0-alpha3: Fixed import of multi-material AMF files, calculation of mesh volume in the right panel after applying a transformation and flipped normals when importing some 3MFs.
Implemented processing of M109 G-code (set hot end temperature and wait) by the G-code viewer #7050 #7099.
Save (CTRL+S) is newly enabled for unnamed projects, it is equivalent to Save As #7054.
Fix by Netfabb is again available for all models, even those reported as manifold #7063.
Numeric inputs in 3D scene newly accept localized decimal separator. For example, one may enter decimal comma into the Cut by plane clipping plane height #7056.
Multipart objects are not supported in SLA mode, thus when a new SLA printer is added through the Configuration Wizard, it is only activated if there are no multipart objects on the Plater.
Mesh simplification tool did not work correctly when applied on a model volume or a modifier mesh.
Object transformation values at the side panel were barely readable with both dark mode and colored background of the coordinate text boxes enabled #7012.
Modifier context menu at the side panel was made consistent with the modifier context menu in the 3D scene.
With background processing enabled, background processing did not restart after Undo / Redo #7040.
Windows specific: Tooltips on "Slice now" and "Send to OctoPrint" buttons were getting in the way when clicking the buttons.
Fixed crash when turning on shells visibility in preview with background processing active.
Added automatic update of legend when switching on/off travel visibility in preview #7068.
Fixed non-uniform scaling of a volume using the part manipulation panel #6380.
Windows specific: Dark mode config option is now available in standalone G-Code Viewer.
Modifiers added to an object from the Shape Gallery are newly centered first before calculating their initial position relative to the object.
Fixed regression wrt. PrusaSlicer 2.4.0-alpha3 due to G-code export parallelization: Standalone G-Code Viewer was again changing timestamp of the imported G-code #7005.
Fixed another regression due to G-code export parallelization: M106 (fan speed) was exported on every layer #7094.
Fixed crashes with some models on SLA hole drilling.
Fixed "out of print bed" indication for objects partly below the print bed.
Disabled acceleration control if default_acceleration parameter is zero. The user interface already suggested this condition by graying out the per feature acceleration parameter fields with default_acceleration zeroed, but the G-code generator did not respect that #3409, #6743 thanks @jschuh.
Improved fuzzy skin options wording ("walls" instead of "perimeters") #7082, #7083, thanks @nsheridan.
Fixed confusing cooling hint when min and max fan speed are equal #3270.
Fixed variable layer editing disabled with raft enabled, this was a regression wrt. PrusaSlicer 2.4.0-alpha1 #6999.
Fixed paint on supports showing through model in certain orientations #5050.
Multi-material painting tool: Fixed incorrect propagation of bottom surfaces with objects partially below print bed #7107.
Fixed spurious "Supports print better with detect bridging perimeters" enabled on application start-up #6814.
Fixed incorrect estimated print time on G-code horizontal slider for MMU prints #7110.
Build, infrastructure:
Updated documentation about building on Windows (thanks @jschuh, #6867)

Prusa Slicer Changelog

What's new in Prusa Slicer 2.7.4

New in Prusa Slicer 2.7.3 RC 1 (Mar 27, 2024)

New in Prusa Slicer 2.7.3 Beta 1 (Mar 26, 2024)

New in Prusa Slicer 2.7.3 Alpha 1 (Mar 21, 2024)

New in Prusa Slicer 2.7.2 (Mar 1, 2024)

New in Prusa Slicer 2.7.2 RC 1 (Feb 24, 2024)

New in Prusa Slicer 2.7.2 Beta 1 (Feb 21, 2024)

New in Prusa Slicer 2.7.1 (Dec 14, 2023)

New in Prusa Slicer 2.7.0 (Dec 3, 2023)

New in Prusa Slicer 2.7.0 RC 2 (Nov 22, 2023)

New in Prusa Slicer 2.7.0 RC 1 (Nov 16, 2023)

New in Prusa Slicer 2.7.0 Beta 1 (Nov 13, 2023)

New in Prusa Slicer 2.6.1 (Sep 6, 2023)

New in Prusa Slicer 2.6.1 RC 2 (Sep 2, 2023)

New in Prusa Slicer 2.6.1 RC 1 (Aug 23, 2023)

New in Prusa Slicer 2.6.0 (Jun 20, 2023)

New in Prusa Slicer 2.6.0 RC 2 (Jun 14, 2023)

New in Prusa Slicer 2.6.0 RC 1 (Jun 10, 2023)

New in Prusa Slicer 2.6.0 Beta 4 (Jun 3, 2023)

New in Prusa Slicer 2.6.0 Beta 3 (May 27, 2023)

New in Prusa Slicer 2.6.0 Beta 2 (May 17, 2023)

New in Prusa Slicer 2.6.0 Beta 1 (May 14, 2023)

New in Prusa Slicer 2.6.0 Alpha 6 (Apr 1, 2023)

New in Prusa Slicer 2.5.2 (Mar 30, 2023)

New in Prusa Slicer 2.5.1 (Mar 15, 2023)

New in Prusa Slicer 2.6.0 Alpha 5 (Mar 6, 2023)

New in Prusa Slicer 2.6.0 Alpha 4 (Feb 18, 2023)

New in Prusa Slicer 2.6.0 Alpha 3 (Feb 3, 2023)

New in Prusa Slicer 2.6.0 Alpha 2 (Jan 31, 2023)

New in Prusa Slicer 2.5.0 (Sep 7, 2022)

New in Prusa Slicer 2.5.0 RC 2 (Aug 30, 2022)

New in Prusa Slicer 2.5.0 RC 1 (Aug 20, 2022)

New in Prusa Slicer 2.5.0 Beta 1 (Aug 15, 2022)

New in Prusa Slicer 2.5.0 Alpha 3 (Jul 15, 2022)

New in Prusa Slicer 2.5.0 Alpha 2 (Jun 30, 2022)

New in Prusa Slicer 2.4.2 (May 1, 2022)

New in Prusa Slicer 2.4.2 RC 2 (Apr 13, 2022)

New in Prusa Slicer 2.4.2 RC 1 (Apr 5, 2022)

New in Prusa Slicer 2.4.1 (Apr 5, 2022)

New in Prusa Slicer 2.4.1 Beta 3 (Feb 24, 2022)

New in Prusa Slicer 2.4.1 Beta 1 (Feb 1, 2022)

New in Prusa Slicer 2.4.0 (Dec 27, 2021)

New in Prusa Slicer 2.4.0 RC 2 (Dec 17, 2021)

New in Prusa Slicer 2.4.0 RC (Dec 15, 2021)

New in Prusa Slicer 2.4.0 Beta 4 (Dec 11, 2021)

New in Prusa Slicer 2.4.0 Beta 3 (Dec 5, 2021)

New in Prusa Slicer 2.4.0 Beta 2 (Nov 27, 2021)

New in Prusa Slicer 2.4.0-beta1 (Oct 26, 2021)

New in Prusa Slicer 2.3.3 (Oct 26, 2021)