Houdini Changelog

What's new in Houdini 17.5.141

Apr 18, 2019

Houdini 17.5 introduces PDG which is designed to enhance SideFX’s procedural architecture to distribute tasks and manage dependencies to better scale, automate, and analyze content pipelines for Film, TV, Games, Advertising and VR. In addition, there have been a number of enhancements to key features such as FLIP Fluids, volumes, destruction tools and more.

New in Houdini 17.0.352 (Oct 19, 2018)

Houdini 17 Banshee introduces powerful new physical simulation tools such as the Vellum multi-solver for fast cloth, a new organic white water solver and material-based destruction workflows. In addition, significant enhancements can be found in Houdini’s interactive modeling and procedural UV tools, erosion models for terrain, character rigging and animation, a brand new 3ds Max plug-in for Houdini Engine, and much more.
VELLUM:
Fast Cloth:
The new VELLUM cloth solver is OpenCL accelerated and easy to set up and control. This XPBD inspired solver supports multi-layered, panelled and draped cloth and includes dynamic constraints for stitching, branching and tearing. A Simple Cloth tool lets Houdini Core users set up a simulation using cloth, collision geo and gravity and wind forces.
VELLUM
Multi-Solver:
VELLUM is a fast unified solver for cloth, hair, soft bodies and grains. Using Houdini FX, you can create simulations that incorporate all of these effects for creating unique results.
GROOMING:
Including VELLUM Hair & Fur:
Grooming hair in the viewport is significantly faster providing a better workflow for artists. These tools incorporate the Vellum hair solver for fast simulation and there are new shelf tools for generating Hair cards for gamers.
MATERIAL-BASED:
DESTRUCTION FX:
Material-based Destruction Tools make it easier to set up and art direct destruction shots by providing tools for pre-fracturing materials such as concrete, glass and wood while automatically building constraint networks that tie the whole system together.
WHITE WATER:
FLUID SOLVER:
The White Water Solver has been rewritten to achieve a more organic, foamy, look with realistic cellular patterns and repellant forces and a more accurate relationship to the source FLIP sim.
PYRO FX:
Sourcing and Retiming:
Houdini can now use OpenVDB as a Pyro FX source providing a more efficient and flexible solution that makes it easier to create the right look for your fire and smoke. Retime is a powerful tool for stretching out or slowing down fluid sims, RBD sims and volumes with effective interpolation and blend options for creating clean results.
INTERACTIVE:
Modeling :
Interactive Modeling includes a new PolyDraw tool which lets you use interactive “Topo Build” tools anywhere in your scene, free from dense reference geometry; fast construction plane alignment and positioning; rotation snapping; view and construction plane memories; and new geometry alignment tools.
UV WORKFLOW:
Fully Procedural:
New UV tools define a fully procedural workflow that starts with automated seaming then moves on to accurate flattening and super efficient layout of the resulting UVs.
TERRAIN:
Advanced Erosion and Hierarchical Scattering:
Terrain now includes advanced erosion tools with more control over details such as fluvial lines, river banks and debris and new hierarchical scattering for more efficient placement of elements into landscapes.
CHARACTER:
New Timeline, Keyframe Workflow
and Facial Autorigging Tools:
Character Animation & Rigging has been improved with a newly designed Timeline (i.e. playbar) that supports a more animator-friendly keyframe workflow and facial auto-rigging tools for a complete top-to-bottom auto-rigging solution.
HOUDINI ENGINE PLUG-INS:
Houdini Engine is now more versatile with a brand new 3ds Max plug-in that integrates with the host application's stack interface, and a Unity plug-in 2.0 that works with prefabs, packed primitives and Houdini's Terrain tools. There have also been important enhancements to the Maya and UE4 plug-ins.

New in Houdini 16.5.439 (May 10, 2018)

DYNAMICS:
Houdini is known for its dynamic simulation tools and with Houdini 16.5 a number of key improvements have been made to the simulation of liquids. These new tools add new levels of realism while making you much more productive. These efficiencies allow you to either create bigger more impressive effects or allow small studios and individual artists to achieve effects that would have been prohibitive given hardware constraints.
BUBBLE SIMULATION:
In the past, simulating fluids was easy but adding bubbles became a secondary task that would often lack the proper realism. With Houdini 16.5, you can now use air incompressibility to create realistic movement of air within a fluid simulation. Now bubbles are a directable part of your simulation and the results are natural looking and highly realistic.
NARROW BAND:
Imagine creating fluids sims that are 3X faster while consuming 3X less memory. The new Narrow Band fluid sims in Houdini 16.5 achieve these efficiencies by allowing you to focus on the liquid’s surface. Instead of processing the whole fluid band, only the Narrow Band is calculated while the quality of the splashes remain the same.
CHARACTER:
Houdini has tools for rigging and animating characters, adding Character FX such as muscles, hair and fur and generating realistic crowd simulations. With Houdini 16.5, these tools get even stronger with features such as time-space motion path handles, enhanced grooming tools and facial and quadraped support in our autorigs. Houdini continues to strengthen this toolset and is production-ready as you take your characters to the next level of realism.
GROOMING:
The hair and fur framework introduced in Houdini 16 has been enhanced with new grooming tools designed with the artist in mind. Use the Curve Advect tool to set up large scale grooming directions by drawing a few quick curves. Easily add guard or white hairs for animal fur and partition your model into different areas to create local grooms that can be merged into a single fur once you are ready. These new tools will make it easier than ever to achieve the look you want as you add hair and fur to your characters and creatures.
RENDERING:
Rendering in Houdini 16.5 is faster and more efficient with optimizations to the VOP nodes used to build materials. With each new release, the goal is to find ways to make it easier to render with Mantra and the new rounded edge shader is a big step forward for a number of key reasons.
ROUNDED EDGE SHADER:
In real life sharp edges don’t really exist and artists often spend a lot of time adding geometry to their models to create visible highlights when you render. With the rounded edge shader, you can leave sharp edges on your model then round them without adding any extra geometry. This feature can also be used to weather the edges of objects and game artists can bake out the results to low-res geometry.
MODELING:
From enhancements to topobuild to improvements in working with soft radius selections, Houdini 16.5 continues to strengthen our growing modeling toolset. Whether you are creating game art, preparing a model for large scale destruction or modeling a character, Houdini has the right tool that is supported by our non-destructive procedural workflow.
POLYREDUCE:
More and more 3D artists are encountering huge datasets such as scanned meshes that need to be simplified. The new Polyreduce tool in Houdini 16.5 lets you efficiently perform large reductions while preserving profiles, UVs and more. The robustness of this feature makes it an important part of your toolset to the point that it can replace 3rd party poly reduction products you have come to rely on.
UV ENHANCEMENTS:
The UV workflow in Houdini 16.5 is much more artist-friendly and includes important enhancements to how you work with UV layers. Advanced packing algorithms have been added to the UV layout tool that are faster and more efficient. You can also control the UV region more interactively and easily evaluate for region overlap or flipped UVs. These improvements will be especially important for game artists building models in Houdini.
UI/WORKFLOW:
It doesn’t matter how powerful your tools are if they are not easy to work with. Houdini 16.5 introduces a new Hotkey manager for quick access to your tools including the ability to use any key to access radial menus. The parameter pane now has a searching ability that lets you filter the visible parameters down to a particular parameter name or even a parameter value. There is also the ability to integrate a game controller to move a camera or control an object in your scene.

New in Houdini 15.5.523 (Jul 11, 2016)

Geometry:
New: Rewrote PolyBevel SOP to do state-of-the-art beveling.
New: Rewrote Polysplit SOP with better interactive insertion of edges and edge loops.
New: Rewrote Dissolve SOP to be more intuitive, faster, and more reliable.
New: Delta Mush deformer smooths arbitrary deformations applied to a polygonal mesh, without smoothing out the detail of the original model.
New: PolyExpand2D now supports variable width offsets and primitive attributes. This is important for road generation and roofing offsets.
New: TopoBuild has new tools for splitting polygons and brushing to move or smooth points.
Improved: Ability to straighten, space evenly, and make circles with the Edit SOP using the menu.
Improved: Better/tighter packing of UV islands in the UV Flatten and UV Layout SOPs.
Improved: Faster saving of large polygon soups under some conditions, most notably IPR renders.
User experience:
New: You can now copy and paste multiple rows and columns in the Parameter Spreadsheet. You can use this to copy all channel references on a node to another node at once.
New: The viewport now shows displacements for surfaces with a GL Displacement map parameter. See the Open GL ROP and on the Effects tab of the 3D Display options. This feature requires OpenGL 4.0.
New: New option for Euler tumbling in the viewport allows you to tumble the view over the poles.
New: Ability to double-click for edge loop selection as well as create multiple loops.
New: Double-click points or primitives in the viewport to select connected geometry.
Improved: Cleaner help layout and improved search.
You can switch the display of lists of items such as HOM methods and environment variables to alphabetical order.
The search now shows "inline" results for nodes, VEX functions, HOM functions/methods, HScript commands and expressions, and common attributes.
A list of categories to the left of search results lets you filter the results quickly.
Improved: Various handle UI improvements including the display of an outer ring for rotating around the current view axis, the ability to turn off negative axis drawing of translate handles, and the display small draggable translate planes away from the center of the handle. For information, see Using handles.
Improved: Improvements to the File Chooser.
Improved: Better geometry snapping, including the ability to snap to X-ray geometry.
Improved: HOM interface for Flipbooking. For more information see hou.FlipbookSettings.
Fixed: Overlapping multi-selections in Dopesheet and Playbar.
Crowds:
New: New foot planting workflow supported by new parameters on various nodes.
New: Transition graphs let you specify multi-clip transitions at specific frames between agent states.
New: You can now directly import or render FBX characters as agents.
New: Added many new controls to the Crowd State DOP for animation clips, such as options for adjusting the clip and/or locomotion speed, retiming behavior, and allowed speed variance.
New: The new Agent Terrain Adaptation SOP lets you add terrain adaptation to animated agents after a simulation, or use it for simple crowd shots that don’t involve simulation.
New: New Agent CHOP imports clips from an agent primitive into CHOPs.
New: New Mocap Biped 3 character on the Character shelf tab. This character has better walk cycles, making it useful to test the new foot-planting features.
New: Houdini now uses vertex normals when deforming agent shapes. This is particularly useful for FBX files, since they typically have vertex normals.
New: Added support for baking additional (non-transform) channels into agents' animation clips. The new Foot Plant CHOP uses this to add channels describing when a foot is planted.
Changed: New versions of the Crowd Solver, Crowd State DOP, Crowd Transition DOP, Crowd Source SOP, Agent Prep SOP, and Agent Terrain Adaptation DOP.
The new versions move, rename, and reorganize some parameters to make the behavior of and interaction between the parameters clearer.
Changed: The Crowd Source SOP is now optional. Any required attributes are initialized by the crowd solver if they don’t already exist.
Changed: Redesigned parameter interface for crowds
Changed: Added support for agents that do not face down +Z and/or are not Y-up.
Changed: The Agent Configure Joints SOP can now automatically compute initial joint limits from an agent’s animation clips.
Improved: Crowd steering behavior, which reduces sliding and spinning for agents.
Improved: Support for locomotive clips, specifically looping and transitioning between locomotive clips.
Improved: Usability and robustness of the crowd shelf tools.
Improved: Terrain adaptation and support for foot locking.
Improved: Enhanced clip-driven transition controls for crowds.
Lighting and rendering:
New: VR lens shader, which supports standard projection modes (latlong/cubemap), as well as control over eye separation and eye/neck distance. The Oculus Rift headset is being used to validate the output image format. A Perspective mode has also been added to the shader, to allow rendering of stereo pairs.
New: There is now curvature support for UV Bake. This is done with a new Curvature VOP that provides various properties of surface curvature, such as Gaussian, mean, convexity, concavity, and magnitude. Curvature can be used to add wear to surfaces, and as a control mask for dirt and rust. An output is now available on the VR lens shader for this type of shading.
New: Depth of Field and Motion Blur are now available in the OpenGL ROP.
New: Third party rendering in Houdini Indie.
New: You can now add a Photon modifier property to objects to control how Mantra traces photons through the scene.
New: New UV Triplanar Projection VOP lets you project repeating textures onto geometry easily.
New: SOHO output drivers have a Render to Disk in Background button. This works like all other Render … in Background buttons, requiring a saved .hip file to work properly.
Changed: The Bake Shader has been removed, with the functionality being moved into the VR lens shader. This means that any image plane can be baked, as opposed to be limited to a fixed set of planes.
Changed: Bake shading controls have been moved from the Bake Texture ROP to standard shaders, which means bake settings can be adjusted on a per-object basis.
Improved: HQueue performance optimizations. The web interface and RPC are significantly more responsive.
Improved: Optimized tree view picker for the Alembic SOP
Improved: Alembic ROP’s exporting of packed fragment primitives.
Improved: The point replicate procedural now has an option to unpack the template geometry.
Fixed: You can now render extra “overscan” image data outside the display window in image formats that support it (for example .pic and .exr). This extra image data may be useful to other software such as Nuke.
Hair, Fur, and Grooming:
New: You can now change selections within a single Curve Groom SOP.
New: A Length Scale parameter on the Appearance tab of the Fur Object allows for small post groom adjustments.
New: UDIM support for hair shader textures.
New: Parameter to control which attributes to keep on external guides.
New: Hair shader asset. The hair material in the gallery and the Fur object both use this, so from now on they will be in sync.
Improved: When the current object is a fur object or you are inside a fur object, the skin painting tools will use that object without asking for a selection.
Improved: Restored stroke caching in the Curve Groom SOP.
Fixed: Fixed a bug where attributes called "prim" and "primuv" were created on external guides when Snap to Skin was on.
Fixed: Fixed a bug where creating a new Curve Groom node using one of the grooming shelf tools (for example using Ctrl+Click or after selecting a different set of primitives) copied invisible parameters, which could cause cached guide geometry to be transferred to the new SOP.
Scripting:
New: You can now script the creation of flipbooks. See hou.FlipbookSettings.
VEX:
Improved: Faster VEX loading and lower memory usage. This affects all VEX code from Wrangle SOPs to Mantra shaders.

New in Houdini 15 (Jul 11, 2016)

User experience:
Scene view:
Display quality:
New: GGX and PBR in the viewport. More to come in future releases.
New: The viewport now displays mitred joints on open curves with thickness.
Changed: In "Normal" lighting quality, environment lights now provide an ambient lighting factor.
Fixed: Improved hair shading in the viewport. Hair shading is now on by default on the Fur object. Hair thickness, subdivision curves, and hair shadows display properly in the viewport’s high quality display mode.
Fixed: High quality lighting mode again supports and unlimited number of lights.
Fixed: Normal quality lighting will now display lighting from an environment light with an environment map. This is currently limited to one light. The Roughness parameter controls the blurriness of the map.
Fixed: Default Phong/Lambert lighting models in the viewport are now more energy preserving. Specular highlights will look more subtle overall.
Textures:
New: The viewport can now display UDIM textures. If an object’s OGL Texture parameter has %(UDIM)d or %(UDIM)2d in the string, it will be treated as a UDIM texture. For example, instead of /path/to/texture1001.exr, you would use /path/to/texture/texture%(UDIM)d.exr.
New: The viewport can also display Mari-style tiled textures. You can use %(U)d_%(V)d or %(UVTILE)d.
New: New options in the display options to highlight geometry/UV boundaries, and highlight overlapping UVs.
New: The viewport can now display world-space normal maps.
Tab menu:
New: In the ? Tab menu you can press ^ Ctrl + Enter to invoke the highlighted tool in the same way as ^ Ctrl-clicking a tool on the shelf. For example, pressing ^ Ctrl + Enter on the Sphere tool will create the sphere immediately at the origin instead of entering a placement mode.
Visualizers:
New visualizers:
New: Volume visualizer displays a color map or vectors showing the values along a slice of a volume.
New: Tag visualizer displays a label pointing to the target. You can set the label to be visible even when the target is outside the view. This is useful for keeping track of light names.
Visualizers tab:
New: When a visualizer is attached to a node, a Visualizers tab appears in the node’s parameters containing the visualizer controls.
Quick visualization:
New: You can hover over a geometry node, dynamics node, or VOP output and press X to attach a visualization node to it. Pressing X on something else in the network moves the visualization node. This is a quick way to move through the network inspecting geometry.
New options:
New: Added a menu of ramp presets to the color visualizer interface.
New: Added options to the marker visualizer:
Color vectors and vector trails by vector values, vector directions, or a second attribute (for example Cd). This supports converting multi-component values, and mapping onto a ramp.
Color point trails by vector values, direction, or an attribute.
Normalized vector lengths.
New Unit length parameter makes it easier to distinguish between per-frame and per-second unit vectors.
In the axes visualization style, you can now enter a space-separated list of three vector attribute names in the Attribute field. The three barbs of the axis will align to the three vectors. Other styles ignore all but the first name.
Improvements:
Fixed: The default attribute type is now "Auto", which guesses the attribute type from the name. This means you only have to change it if you have two different types of attribute with the same name.
Fixed: A higher-priority visualizers will no longer override other visualizers (or Cd) if the attribute it’s visualizing does not exist.
Network and parameters:
Match transform:
New: Objects now have buttons in the parameter editor to copy the position, rotation, scale, and pivot from another object in the viewport.
@ syntax
New: There are now @attribute alternatives to all local variables. For example, you can use @P.y instead of $Y, @Cd.r to get the red component, and @name to get the name string.
Changed: @Frame is now a floating point value, to match the VEX equivalent.
Fixed: @Frame and @Time now work properly in nodes that don’t have local variables.
Auto connect:
New: In the ? Tab menu you can press ? Shift + Enter on the highlighted node to automatically place it and append it to the previously selected node.
Context menu:
Changed: The context menu for nodes has been reorganized using submenus to hide infrequently used options, making the menu much smaller.
You can copy $HFS/houdini/OPmenu.xml into your user preferences folder and edit it to customize the context menu. See the [menu configuration XML format||/basics/config_menus].
Digital assets:
Black box:
New: You can now create "black box" assets that can be freely distributed and used without a license, but cannot be inspected or modified. Select an instance of an asset and choose Assets ? Create black-boxed asset.
Show on connect:
New: The Disable when and Hide when syntax now supports the pseudo-functions ninputs() and hasinput(n) to allow hiding/disabling depending on whether an input is wired.
.hda
Changed:L Houdini now saves asset libraries with a .hda extension instead of .otl. Houdini still recognizes and loads files with the old extension.
(Setting the HOUDINI_USE_OTL_AS_DEFAULT_HDA_EXT environment variable will restore the old .otl extension. This is a temporary stop-gap for studios that have infrastructure that relies on the old extension.)
User data:
Developer: You can use the hou.HDADefinition.setUserInfo and hou.HDADefinition.userInfo methods to store and retrieve arbitrary text data on an asset. This might be more convenient than using a section. Note that adding user info will make an asset unreadable by earlier versions of Houdini.
Customization:
Python panels:
New: Python panels can now use hou.ui.createQtIcon to access Houdini icons a QIcons.
New: Python panels now support drag and drop from Houdini into the panel.
Changed: The menu of available pane types now includes Python panels.
New parameter type:
New: This version of Houdini introduces initial support for a "data" parameter type you can use to store binary data in a node. For example, the Curve Groom SOP uses this to store stroke data.
Menu customization:
Changed: Improvements to the menu customization XML format:
Now supports multiline context expressions.
The and elements now have an allowRedundantSeparators attribute. When this is "true", Houdini will not automatically remove redundant separator items from the menu.
You can now add dynamic menu strip elements as children of the element.
You can now use a element in place of a to dynamically generate the label from a Python expression.
The parameter context menu configuration (PARMmenu.xml) now supports an element inside the element. This lets you use a Python expression to show or hide menu items based on the type of parameter the user right-clicked.
See customizing menus for more information.
HDK:
Developer: HDK plugins can now register mouse hooks in the viewport.
Other changes and improvements:
Tree view:
Fixed: You can now select multiple items (in the same network) in the tree view.
Handles:
Changed: By default, rotation ring handles that are straight on to the view are no longer drawn. You can turn off Hide rotate handle rings parallel to the view direction in the Handles preferences to disable this.
Group list:
Fixed: You can now use numeric ranges and attribute expressions (such as @area>0.1) in the group mask field.
Deprecation:
Changed: Houdini will now display a warning if you load a scene file containing deprecated nodes (nodes that we intend to remove from Houdini in a future version). You can turn this off in the "Save and Load" preferences.
Expression literals:
New: You can now use _ as a number separator in Houdini expressions, for example rand(1_000_000), to make long numbers more readable.
Version number:
New: The version number is now part of the application icon.
New: A new environment variable $HOUDINI_VERSION contains the full version number (for example 15.0.123).
Changed: The viewport no longer displays environment maps as background images for light types other than Environment.
Misc:
New: The hgpuinfo utility prints information about OpenGL and OpenCL support on the current machine. You can also test for feature support using the exit code.
Changed: The Cache SOP generates a warning if you try to cache packed primitives in point mode.
Changed: Re-enabled checks for stereo framebuffer support and quad buffer stereo mode.
Changed: Houdini now assumes parameters starting with stdswitcher are auto-generated folder parameters, so it doesn’t consider their deletion or change as changes to the asset.
Fixed: Distance lights in the viewport now properly ignore attenuation.
Fixed: Instanced geometry that’s animated at the geometry level now updates properly in the viewport.
Fixed: Adaptive subdivision surfaces now look correct in "wireframe ghost" and "hidden line invisible" display modes.
Fixed: Dragging in the viewport now works with distance handles.
Fixed: The Attribute class option for visualizers now defaults to "Auto", which figures out the type of the attribute based on the name, so you shouldn’t have to change it unless you have two different types of attributes (for example point and primitive) with the same name.
Fixed: HUD sliders now work in the UV viewport.
Fixed: The viewport now returns to the previous state after the user uses the reselect button on a group parameter.
Fixed: Fixed display of multiple selections (for example, where a tool asks for a set of "source" primitives and then a set of "destination" primitives) when using modeling tools in the viewport.
Fixed: The "Lock camera/light to view" button to the right of the viewport now affects all linked viewports with a camera.
Fixed: Point trails now work on packed fragments.
Fixed: Fixed display of bump maps with XY deltas.
Fixed: Improved startup times by caching information about plugins.
Fixed: The Assets menu now lists assets from read-only libraries.
Fixed: The level of detail display option is now saved in the .hip file.
Geometry and modeling:
Interactive:
New poly tools:
New: The Poly Bridge node builds sheets or columns connecting edges or faces. The node has controls for the shape and topology of the bridge, including following a curve.
New: New Poly extrude version extrudes sheets or columns from selected edges or faces. The node has controls for the shape and topology of the extrusion, including following a curve.
New: New Poly Expand 2D node dilates or expands the outlines polygons. It can also create width from lines, making it ideal from creating roads from path lines.
Basic modeling:
New: The Edit node has a more free-flowing interaction like a "tweak" tool.
You can select faces, edges, or points on-the-fly instead of switching between different components.
You can slide edges and edge loops across the surface.
The geometry under the mouse highlights in the viewport to show what will be selected.
You can constrain points and faces to slide across adjacent faces.
A Hide handle on immediate selection drag parameter lets you hide the handle while you're tweaking.
New: The Soft Transform and Soft Peak nodes now let you visualize the falloff using a visualizer on a new vis_falloff attribute, instead of overwriting the color attribute (Cd).
Changed: Using the T, R, and S keys in the Edit, Transform, UV Transform, or UV Edit tools now changes the handle within that tool, instead of switching to the general Move, Rotate, or Scale tool.
Changed: When you're working in the Edit, UV Edit, or brush tools, the Q (Repeat current operation) and ? Shift + Q (Branch and repeat current operation) hotkeys will now create a new node instance.
Changed: The Edit tool now hides the handle while you're pressing the loop selection hotkey A.
Selection:
Changed: Houdini now preserves the component selection across cooks, and remembers different selections for each component type, instead of converting the current selection when you change types.
Basically, you should be able to select faces, go to a different object or change to a different component type, come back, and still have the same faces selected.
(You can still convert the selection to a different type using an item in the context menu.)
Changed: Edge selections now show the direction of each edge. You can change the direction of a selected edge direction by ? Shift-clicking the edge.
Fixed: Edge selection now does a better job of preserving selection order.
Group list:
New: You can now select whole branches of attribute hierarchies in the group list interface, for example with an Alembic path attribute.
New: There is now an option in the group list’s settings menu to highlight group names in the list as you move the mouse over components, instead of changing the contents of the list to only show the groups containing the component under the mouse.
New: You can now customize the colors assign to groups in the group list. Click the color swatch to change the color. ^ Ctrl-click to clear the custom color. You can use the hou.hipFile.groupColorTable and hou.hipFile.setGroupColorTable HOM functions to script the color overrides.
New: You can now collapse and expand branches of Alembic hierarchies in the group list.
Changed: Changed default group list colors to prevent confusion with the selection.
Quick visualize:
New: Visualize geometry node helps visualize the output of different nodes in the network. Any visualizations you attach to this node will be applied to the node it’s wired from. You can hover over a geometry (SOP) node and press X to rewire the visualize node onto that node.
The intention is to later replace this somewhat inefficient method with something more integrated with the visualization editor.
Bend node:
New: Bend node is a more interactive version of Twist. It lets you define two planes and twist, bend, or taper any geometry between them.
Changed: The Twist, Linear Taper, and Bend tools on the Deform shelf tab now use the new Bend node.
Smooth:
Fixed: Improvements to the Smooth geometry node:
Much faster and partly parallelized for large models.
Can smooth multiple attributes.
Works with polygon soup tetrahedrons.
Respects primitive groups when smoothing vertex attributes.
Supports attributes with tuple size of 4 or more.
Selection settings:
New: There is now an "Objects and geometry" preference to always start with area selection set to visible geometry only (so box selection won’t select polygons through the other side of visible geometry).
Procedural:
Looping:
New: Block Begin and Block End nodes allow looping the nodes between them. See the documentation on looping. This block functionality is easier to use than previous solutions such as the For Each subnet and Solver SOP.
Group syntax:
New: The group selection syntax now supports using @attr=val,val,val to compare an attribute to a list of possible values. For example, @id=1,2,90,120. For string attributes, you must enclose values containing spaces in double quotes, for example @path=/foo/*,/bar,"some string".
Fixed: You can now use "intrinsic" attributes in group selection syntax like regular attributes. For example @intrinsic:indexorder

New in Houdini 14 (Jul 11, 2016)

User experience:
New: Geometry to select/snap is highlighted. (You can turn highlighting off in Edit ? Preferences ? 3D Viewports.)
New: Better edge-loop selection.
New: New visual controls for selecting groups and disconnected pieces in the viewport.
New: Fast and accurate. The 2 3 4 5 keys now always go into component selection mode. The view change keys are now mapped to Space + 2, Space + 3, and so on.
New: Group parameters on surface nodes (which select which components the node applies to) now have a Reselect button that lets you interactively change the selected geometry in the viewport.
New: Selection is preserved after geometry cooking.
New: Snapping is faster and more accurate.
Changed: Selecting groups now uses the group name in the node instead of a long list of the contents.
Changed: Picking primitives in the viewport now acts as if they were solid even in wireframe mode. You can turn this off in the Display Options.
Handles:
New: New box handle type.
New: Highlighting of handle components, context-sensitive cursor.
New: Indirect dragging with .
New: You can now click anywhere in a HUD slider to set the value. ^ Ctrl + resets a HUD slider to the default value.
New: Handles now have tooltips that explain supported modifier keys.
Changed: he handle grow/shrink hotkeys are now * and /. + and - have been changed to show or hide subdivisions in the view.
Changed: The M key now cycles between transform handle alignments. Moved switching brush modes in the Edit SOP to the B key to accommodate this change.
You can use ? Shift + Y to cycle handles in reverse, and ? Shift + B to cycle alignments in reverse.
Changed: Mouse wheel now resizes brush in various tools (including brush selection).
Changed: New handle size preference and hotkeys * and / to grow and shrink handles.
Changed: Global settings on a handle’s menu are now preserved for new handles.
Customization:
New: New groupings and control types in parameter interface editor.
New: New Assets menu makes working with digital assets easier. Create an asset from selection, lock/unlock/save, quick access to Orbolt store.
New: File ? New Project and File ? Set Project make project management easier. The Set Project menu item sets the $JOB environment variable.
New: Usage statistics collection and querying. Customizable by studios, optionally sharable with Side Effects.
New: Button parameters can now use an icon instead of a text label.
Developer: Custom panel types with Python and PySide.
Any parameter can have an associated action button next to it that runs a custom Python script.
User interface:
Changed: Houdini now uses Qt as the foundation of its GUI.
Changed: New modern embedded browser based on WebKit.
Viewport:
New: New scriptable and extensible visualizer architecture replaces the custom attribute controls in the display options.
New: Playback is 3-10× faster. Faster display of Alembic geometry.
New: Higher quality geometry display in 3D and 2D viewports.
New: Added a Show Materials icon to the display toolbar. Turn this off to show the same default material on all geometry.
New: New Wireframe Ghost display mode draws hidden lines more faintly for better clarity than wireframe.
New: New controls in the viewport display options dialog, including handle and indicator sizes and per-viewport control of background image brightness.
New: You can now use the + and - hotkeys to show or hide subdivision levels in the view.
Changed: Viewport-related prompts and messages now appear in the viewport instead of the status bar.
Changed: Checkered background in UV viewport (with brightness control).
Changed: The Display Normals icon toggles display of both point and vertex normals.
Changed: When you switch between different projection types (e.g. perspective, front, right, UV), Houdini remembers the previous orientation, instead of automatically homing.
Changed: The W key now switches to Ghosted display mode instead of Wireframe. You can change it in the Edit ? Preferences ? 3D Viewports.
Changed: UV polygons and NURBS isoparms now drawn using color attribute (Cd).
Changed: The move, rotate, and scale tools now add a UV Edit node instead of an Edit node when used in a UV viewport.
Fixed: Mac OS X support on par with other platforms.
Fixed: Setting the viewport pivot with Space + Z is now faster for large scenes and works with all primitive types.
Fixed: Viewport shows tetrahedrons natively, with selections and decorations displayed properly.
Developer: OpenGL core profile.
Network and parameters:
New: Enhanced color picker window with color temperature support.
New: Inline color sliders in the parameter editor.
Fixed: You can now align nodes inside a network box. If alignment would move nodes outside the box, Houdini automatically resizes the box.
Fixed: You can now copy parameter spreadsheet selections onto the clipboard as tab-separated text.
Fixed: You can now edit spare parameters on editable nodes inside a locked asset. This also fixes a bug where applying presets to editable nodes inside an asset sometimes wouldn’t work.
Other changes and improvements:
New: The parameter spreadsheet now has a gear menu and an option to show empty rows.
New: New item in the pane menu Maximize vertically/horizontally lets you maximize/restore a pane across the pane split rather than taking up the entire window. The default hotkey is Alt +
New: You can now override the user preferences directory location using the $HOUDINI_USER_PREFS_DIR environment variable.
New: Performance monitor has a Save to file button to save the event log to disk.
New: The 3D viewport’s Display Options window and the display objects toolbar menu button have options to globally enable and disable display of the per-object X-ray and Object Origin options.
New: New Fast/Quality Xray drawing option to speed up x-ray drawing on lower-end GPUs. The default is now Fast.
Changed: The parameter editor now always updates during viewport interaction. The Update UI toggle has been removed. Turn on Edit ? Live parameter display during playback (formerly Edit ? Update parameters interactively) to update parameters during playback as well.
Changed: New .hda default extension for digital asset libraries, replaces .otl.
Changed: The status bar now shows a single cooking node, instead of a stack.
Changed: The $HIPNAME environment variable no longer includes the .hip extension, making it easier to compose it to create new filenames.
Changed: After a full license of Houdini is downgraded to Apprentice by opening a .hipnc file, you can no longer open a new file or do File ? New.
Changed: The tree view pane no longer shows hidden nodes by default. You can change the Show Hidden option in the .desk file to show them.
Fixed: International keyboard support, including dead keys and IME typing. This applies to network notes, parameters, text fields, and code editors.
Fixed: You can now use ^ Ctrl + ? Shift + Z as a hotkey for Edit ? Redo.
Fixed: You can now use elements in the VOPFXmenu.xml file.
Fixed: If you are using Houdini interactively with cook mode set to "never" and load a scene file, the cook mode will remain "never" instead of changing to what was saved in the file.
Fixed: Added screen information to the About Houdini window.
Fixed: You can now open asset libraries using File ? Open.
Fixed: The network editor’s "time dependent" visualization now shows nodes that are "display" time-dependent but not "cook" time-dependent.
Fixed: In the Type Properties and Edit Parameter windows, you can now copy defaults from the node for individual parameters using the context menu. Ramp parameters now have a Help field to enter a tooltip.
Fixed: Handle hotkeys are now configurable in the SceneMouseModifiers file.
Geometry and modeling:
New: Scatter node is rewritten to be more robust and functional. Can now scatter points in texture space, "relax" points away from each other, and pick up more attributes and groups, among other improvements.
New: New Spray Paint node lets you scatter points on a surface interactively.
New: New edge and face loop selection interface.
New: Powerful new UV Flatten and UV Layout tools.
Interactive workflow.
Ideal UV relaxation.
udim support.
Distortion visualization.
Fast point and vertex (boundary) selection.
Pin handles for UV tweaking.
New: New pelting options in the UV Pelt node.
New: Group parameters on surface nodes (which select which components the node applies to) now have a Reselect button that lets you interactively change the selected geometry in the viewport.
New: New Point Relax node lets you spread out points from each other, with options for varying radii.
New: New Attribute Interpolate node makes it easy for points from Scatter, Spray Paint, Ray, Point Relax, and Draw Curve, to stick to deforming geometry, and more generally interpolate attributes inside of primitives or point clouds.
New: New Attribute Randomize node to generate random values of various distributions, especially for random directions, orientations, and scales.
New: New Normal node for easy creation of vertex, point, and primitive normals. Compared to Facet node, point normals are not affected by triangulation, primitive normals are more stable when far from the origin. Supports cusping normals for non-planar quads, and for polysoups created with Merge identical vertices off.
New: Much more powerful rewrite of Triangulate 2D.
New: The new Solidify node constructs a watertight and non-intersecting mesh from its input. This is very useful for tetrahedralizing before use with the FEM solver. This node currently does not support copying attributes over from the input geometry.
New: The new Split node lets you arbitrarily divide the primitives in the input geometry between separate outputs. This is more convenient than using two Blast nodes to delete one part and then the other.
Changed: The selection styles (box, lasso, brush, laser) now each have their own hotkey. Previously a single hotkey cycled between them.
Changed: Nodes that create geometry (e.g. Sphere node, Torus node) now default to higher resolution (more divisions).
Changed: The PolyExtrude shelf tool now sets Keep points shared to "Average positions" by default.
Fixed: Most nodes that create geometry now have uniform scale parameters.
Fixed: You can now animate the parameters of the PolyCut node.
Alembic and packed geometry:
New: Now supports writing/reading geometry with visibility information.
New: Houdini can now lazily load geometry saved in .bgeo and .bgeo.sc files as needed instead of all at once. In the File node, turn on Delayed load geometry, and set Display packed as to something other than full geometry.
New: The Alembic render node has an option to write out packed Alembic geometry using the hierarchy from the Alembic file the geometry came from. The Alembic render node also has a new option to collapse all objects, which is useful for round-tripping Alembic archives using geometry nodes.
New: The Alembic render node has an option to write the geometry from a SOP path. This allows you to use the Build hierarchy from attribute option from the ROP network.
New: New parameter in the Alembic Archive object to flatten visibility computations.
New: New parameter in the Alembic Archive object and Alembic geometry node to import user properties. The properties are stored in JSON format in primitive attributes, and as spare parameters on Alembic Xform objects.
New: To export geometry with user properties, create the primitive string attributes abc_userProperties and abc_userPropertiesMetadata containing JSON maps of user property data.
New: The geometryid intrinsic attribute on packed geometry/fragments identifies the referenced geometry.
New: You can now export animated geometry inside an arbitrary number of subnets.
New: The Repack node lets you convert Alembic and packed disk primitives into packed geometry. The Pack node has a new parameter for whether to create packed geometry or packed fragments. The Unpack node has new parameters to allow transferring attributes to the unpacked geometry.
New: If you enable an abc_lock_geom spare parameter on a geometry object, all geometry in the object will re-use the first geometry sample for all samples when exporting to an Alembic archive.
Changed: Houdini now writes Alembic NURBS in homogenous coordinates, and rationalizes them on read.
Fixed: Maya locators in Alembic files are now loaded with their arbGeomProperties.
Fixed: Display of Alembic geometry is faster in the viewport.
Fixed: Houdini can now export animated display channels to Alembic.
Fixed: The File Merge node can now load packed disk primitives.
VDB:
New: New VDB Activate SDF geometry node.
Changed: VDBs with vector values now apply transformations to the voxels as well (depending on the vector type). This breaks backward compatibility and may result in scenes changing when loaded into Houdini 14 if you use vector VDBs.
Changed: Generated attributes are no longer prefixed with vdb_. This allows you to override shade attributes when using .vdb files. This also means that Houdini now saves all detail attributes to the .vdb file, not just attributes that start with vdb_.
Changed: Converting from fog to SDF using the Convert VDB node now uses a half-width of 3 voxels instead of 1. This ensures a valid level set, but uses more memory.
Fixed: Improved handing of metadata in .vdb files. File-level metadata is now loaded into vdb_dataname detail attributes, and vice versa when saving to .vdb. Saving now preserves 64-bit integer and double-precision attributes.
Fixed: Improved the calculation of VDB area/volume. This may change the output of existing networks that use VDB intrinsics, as well as the Measure and Scatter nodes, which use this calculation.
FBX:
Changed: We now smooth resampled rotations on FBX import.
Fixed: FBX import now consistently uses double-precision floating-point transforms to avoid potential loss of precision.
Other changes and improvements:
New: Use the new Output node to collect outputs in a geometry subnet.
If an Output node is present in a Geometry object and an Object Merge targets the object, Houdini uses the Output node, ignoring the display and render flags.
New: Geometry subnets can now have multiple outputs.
New: New Blosc compression for geometry files (.bgeo.sc) is much faster than GZIP.
New: The Divide node now supports convexing geometry with Max edges off. When Max edges is 3, the node now ignores Triangulate non-planar, which may cause the order of triangles in the output to change if the input has non-planar polygons.
New: The environment variable HOUDINI_PTEX_WINDING controls the expected orientation of ptexture faces. Setting the variable to 1 makes Houdini swap the U and V coordinates. This lets you use data from other software packages, such as Z-brush, that use the opposite orientation from Houdini without having to manually swap the orientation after loading.
New: The Volume Rasterize Particles node has new parameters for controlling the filter and merge methods. Volume Rasterize Particles also supports velocity motion blur by velocity streaking.
New: Attributes can now hold arrays, including string arrays.
New: The Tetrahedralize node now includes options for what to do when the operation fails. It can now tetrahedralize multiple independently connected objects separately, for seamless tetrahedralization of fractured objects.
New: The Connectivity node has a new parameter to specify edges that act as topological boundaries when calculating connectivity. This lets you visualize "islands" created by doing edge loop select (such as for UV Flatten).
New: The Ray node now supports transferring attributes when using minimum distance, and for rays intersecting polysoups. It can now output attributes containing primitive numbers and UVW coordinates where the rays hit. It respects the collision group when colliding against geometry containing metaballs and meta-superquadratics. Now supports Max distance parameter which can significantly improve performance when the colliding geometry is known to be close.
Changed: When you convert an edge selection to a face (primitive) selection, it only selects the faces with selected edges (not shared faces that share points with selected edges).
Changed: Deform, Deform Muscle, and Deform Meta nodes are now created with Deform normals on by default.
Changed: The Point VOP SOP and Point Wrangle nodes are now hidden by default. Use the Attribute VOP SOP and Attribute Wrangle instead. ("Point VOP" and "Point Wrangle" are still available in the UI as aliases to ease the transition.)
Changed: Templated geometry nodes now have a pink indicator ring.
Changed: Surface nodes that save attribute deltas (such as Paint, Sculpt, Edit, Group Paint, and so on) now save them as 32-bit integers or floating-point numbers (unless they are specifically 64-bit values). These changes have been back-ported to Houdini 13.0 and Houdini 12.5, so those versions will be able to load files saved by Houdini 14. Houdini 12.1 and earlier will load Houdini 14.0 files with the nodes but without the saved edits.
Changed: The Attribute node is now the Attribute Rename node. The new Attribute Delete node contains the deletion options from the old Attribute node.
Changed: In general, AttribX nodes have been renamed to Attribute X.
Changed: Nodes and functions that find the closest point on a circle, such as the Ray node's Minimum distance option, or the xyzdist VEX function, will now return positions inside the circle if the query point is inside the circle.
Changed: If you use the Blast node to delete all geometry, the attribute names (e.g. P) will continue to exist in the detail, just with no referents. This is necessary for consistency.
Changed: In .geo and .bgeo files, the type settings for groups are now optional. Houdini no longer writes them to reduce file size. You can set the HOUDINI13_GEO_COMPATIBILITY environment variable to have Houdini write geometry files compatible with Houdini versions prior to 13.0.600.
Fixed: The Deform node is now faster for typical uses (up to 7× faster in one test with quaternion attributes).
Fixed: The Resample node is significantly faster. It now works natively with NURBS and Bezier curves and surfaces, instead of converting them to polygons/polylines. It has new parameters that are useful when converting curves to a point cloud (Randomize first segment length, Create only points, and Distance attribute).
Fixed: The confusing "Keep" options have been removed from the Attribute Delete node.
Fixed: Transform Pieces now also transforms vertex attributes.
Fixed: PolyCap now supports capping polysoups, meshes, and parametric surfaces with polygons. It is faster and produces correct winding order when Unique points is on. The node will now cap all unshared edges unless you specify an edge group. You can turn this off using an option.
Fixed: Group can now find unshared edges in polysoups, meshes, and parametric surfaces.
Fixed: The Copy cell point attributes and Maintain piece numbering options of Voronoi Fracture node are now significantly faster. You can now use the same syntax as Attribute Copy, such as *, to specify which attributes to copy. Voronoi Fracture now generates closed pieces by default, and adds vertex normals for the interior geometry.
Fixed: The Volume Trail node now works with VDB volumes. It now uses the traillen attribute to allow different numbers of trail segments per-point, with a maximum segment parameter to limit them.
Fixed: Volumes with shared voxel arrays will preserve the sharing when exported to .bgeo files. The ability to read this data is back-ported to Houdini 13.0.437 and later.
Fixed: The Cache node now retains cached frames properly when the frame range changes and it overlaps the old range. This lets you to, for example, cache a sliding range around the current frame using $F-3 and $F+3 as the start and end frames. The Cache node now has a second input for cache invalidation. Any change to the geometry in the second input will invalidate the cache.
Fixed: The File Cache node now has a File mode parameter similar to the File node.
Fixed: The orient attribute, along with N, up, and v, is now properly marked as "to be transformed", for example when created by the Attribute Create node with the type set to "guess from name".
Fixed: The Geometry type parameter on the Delete, Group, and Partition has been updated to list all known geometry types instead of a small fixed list of types.
Fixed: The Inherit velocity parameter on Point Replicate can now be negative.
Fixed: The geps utility is now more robust.
Dymamics:
New particle grains:
New: Houdini 14 includes a new Position-Based Dynamics (PBD) POP Grains solver, implemented in VEX. It is particularly well suited to simulating granular materials like sand. See the grains help for more information.
Excellent stacking behavior.
Clumping allows the simulation of wet sand or cement.
Explicit constraints represented as primitives, making them easy to set up and direct. Allows simulation of crumbling sand and tearing strands, sheets and solids.
One-way interaction with rigid bodies.
Highly directable.
Stable interaction between particles with differing material properties.
Supports GPU acceleration using OpenCL, which is typically 2-5× faster. Some features are unsupported in the OpenCL path, please see the POP Grains documentation for details.
Bullet solver:
New: RBD Glue Object shelf tool creates a glue constraint network along with an RBD Packed Object or RBD Fractured Object DOP.
New: New Constraint force mixing parameter controls the default CFM value for constraints.
New: New attributes recognized by the solver.
The speedmin, speedmax, spinmin, and spinmax point attributes limit the linear or angular velocity of an object. Use the POP Speed Limit node to set up these attributes.
The collisionignore point attribute can be used to disable collisions against specific DOP objects or groups of packed primitives (using the values of the collisiongroup point attribute). This attribute can be generated by the POP Collision Ignore node.
The dead point attribute can be used to mark objects for deletion when the solver runs. This attribute can be generated by the POP Kill node.
New: All of the Bullet Data parameters for RBD Packed Objects can be overridden by point attributes with the same name as the parameters (for example, bullet_georep can be used to specify a different collision shape for each object).
New: Added an Overwrite Attributes from SOP parameter to the RBD Packed Object node, which specifies a list of point attributes to fetch from the source SOP geometry at each frame.
New: Added parameters to the Bullet solver and the Hard Constraint Relationship node to control the softness of contact constraints and pin constraints.
Fixed: Many significant performance improvements, which produce 10-20× faster simulations in many situations.
Collision detection is now multithreaded.
Improved scalability for simulations with large numbers of objects.
Computing convex hulls is around 2× faster.
Improved performance for simulations with a large number of initially interpenetrating or closely packed objects.
Fixed: The Bullet solver now supports packed primitives with animated or deforming geometry.
The Initial Object Type parameter on the RBD Packed Object node replaces the Create Active Objects toggle and can be used to set the initial values for the active, animated, and deforming point attributes.
Fixed: The Bullet solver now supports constraints between DOP objects that don’t have a collision relationship.
Fixed: Improved interpolation of kinematic objects when sub-stepping.
Fixed: Improved stability of strong drag forces. The Bullet solver now reevaluates forces at each substep, so increasing the number of substeps on the solver (rather than increasing the DOP network substeps) will produce more stable results.
Fixed: The Bullet solver now supports packed primitives that have the pointinstancetransform intrinsic enabled.
Fixed: The Bullet solver now takes feedback impacts into consideration when breaking glue bonds.
Fixed: Bullet objects can now collide against several types of affectors, including cloth, solid, and wire objects.
Fixed: Changing the P attribute of RBD Packed Objects now correctly translates the objects. The trans attribute is no longer used.
Fixed: The bullet solver can now build collision shapes from capture regions when "geometry representation" is concave, or "create convex hull" is enabled.
FLIP:
New: Improved whitewater: richer froth, distributed.
New: The Whitewater Source geometry node now has a Cache tab allowing you to save candidate points to disk after culling and sampling, but before attribute mapping, allowing faster fine-tuning of emission criteria in large simulations. It also has a second input for only simulation volumes, and an Output points only option, to allow storing particles and volumes separately.
New: FLIP solver has a Kill unmoveable particles option for deleting stuck particles.
Changed: Visualization now defaults to particles rather than sprites.
Changed: Points from Volume and Particle Fluid Tank surface nodes now use the new Scatter surface node's capabilities, and expose its Relax iterations parameter. This can help create flatter surfaces for FLIP simulations.
Changed: The FLIP solver’s Smoothing parameter is now Velocity smoothing, with the default changed from 0.3 to 0.1.
Changed: The defaults for particle birth inside the Whitewater Emitter have been changed to avoid excessive spray. You can increase the Velocity offset to get spray similar to previous versions.
Fixed: Robust handling of extreme scales.
Fixed: Improved collision with deforming surfaces.
Fixed: Faster and better viscosity (5× faster with GPU support).
Fixed: Smoother fluid volumes without loss of detail.
Fixed: Greater scalability for high resolution and sparse fluid configurations with OpenVDB 3.0.
Fixed: Smoother splashes when reseeding is enabled.
Fixed: FlIP solver reseeding now uses a time-varying random function to generate new point positions, with a new Random seed parameter. This fixes a bug that could cause streaking in the particle distribution.
Solids/FEM/Cloth:
New: Improved embedded workflow in finite element solver
Works for both the Cloth Object and Solid Object.
Direct embedding of polygons is now supported.
Embedded positions are smooth instead of barycentric.
Embedding works even if pieces stick out of the simulated mesh.
Embedded polygons and tetrahedrons fracture along with the simulated geometry.
The initial alignment is specified per-vertex.
Now respects connected components in the simulated geometry.
Now writes a velocity point attribute on the embedded geometry.
Supports matching fragment parts in the embedded geometry with fragment parts in the simulated geometry. This requires the fracturepart attribute on both.
New: Solid Object node has Initialize behavior parameter with a menu of physical material presets such as "rubber", "organic tissue", "oak wood", and "cork".
New: The finite element solver can now add vertex attributes for both polygons (cloth) and tetrahedrons (solids) containing the energy and energy dissipation densities. This makes adding secondary effects and visualizations easier.
New: The finite element solver can now add a quality primitive attribute to tetrahedrons, indicating how suitable they are to simulation. You can visualize this attribute to find problem areas in your mesh.
New: The finite element solver now maintains a fracturecount vertex attribute. This is how often the solver has fractured the vertex from any other vertex.
New: For finite element sims with thin surfaces, you can now simulate polygons directly instead of having to make a thin layer of tetrahedrons (using Strong Bend model).
Fixed: × faster simulation.
Fixed: × lower memory usage.
Fixed: Better fracture behavior.
Fixed: The finite element solver now supports sub-steps for fracturing.
Fixed: The finite element solver now saves the rest state in the restP attribute, to avoid conflict with Mantra’s rest attribute.
Fixed: The Solid Object shelf tool now creates better tetrahedron meshes for source geometry with sharp edges.
Fixed: Large deformations of tetrahedrons in solid objects is more robust.
Fixed: The planar force model for Cloth Object is now consistent with Solid Object.
Smoke and fire:
New: Gas Curve Force node lets you direct smoke along a curve for very cool effects.
New: The Gas Substep node has new options to evaluate the CFL condition once per frame, and to quantize to max sub-steps.
New: Added several nodes for simulating vortex filaments, which can be used for effects such as cigarette smoke.
New: Added a Blend parameter to the advection controls of the Gas Advect Field node and the Smoke and Pyro solvers.
Changed: The parameter order of the Pyro SHOP changed (swapped Noise output type and Space parameters).
Changed: The Gas Advect node now supports the higher-order advection methods Trace RK3 and Trace RK4. The FLIP solver has switched to RK3 internally with a higher default particle advection CFL of 0.75 for more accurate advection at roughly the same speed.
Changed: The Gas Advect CL node now supports the Trace Midpoint, Trace RK3, and Trace RK4 methods. The default Trace advection kernel is now automatically accelerated by the Intel OpenCL 2014 driver, giving an approximate 20% increase in Pyro and Smoke solver performance.
Fixed: Optimized Gas Viscosity solver, with new parameter to choose 32 or 64 bit precision and OpenCL support.
Particles:
New: The Look At POP has a new Treat as wind option for the force-based Spin mode that avoids the need for additional drag. New Reference direction and Reference up allow specifying the original particle frame to align.
New: Rewritten POP Source node.
New: New POP Spin and POP Velocity nodes are more convenient than writing an equivalent wrangler.
New: New Spin by Volumes POP spins particles based on vorticity of a velocity field.
New: New Float by Volumes POP gives lightweight floating particles in the output of a liquid simulation.
Changed: The POP solver has a group field to limit responses.
Changed: Collision detection with particles now treats pscale as a radius, matching sand.
Changed: The POP solver now computes collisions the same way as POP collision detect. This is slightly slower but ensures the hitnml attribute is correct. This avoids a bounce when particles start sliding on a surface.
Changed: hittotal is now incremented only once per sub-step, regardless of the number of impacts, for better performance.
Changed: Sliding and stopped particles are no longer involved in collisions in the GAS Integrator.
Changed: The old /part network is now hidden in the user interface.
Fixed: The POP solver now supports the cling attribute. You can set it using the POP property DOP.
Fixed: The Inherit velocity parameter on POP Replicate can now be negative.
Fixed: Support for geometry-based collisions between particles and packed primitives.
Wire:
New: Wire solver now supports fracturing.
New: The Wire solver can now use attributes on the geometry to specify the target shape. Turn on Import target geometry on the Wire Object node to update the attributes at each frame.
Changed: The Wire Object has been restructured to be more consistent with the Cloth Solver and Finite Element Solver, to be make it easier to develop tools that work with all solvers.
Fixed: Improved performance in the wire solver when large POP drag forces are applied to Wire objects.
General:
New: Timeline coloring shows which frames are cached. Blue indicates frames cached in memory. Purple indicates frames being played back from .sim files. Orange indicates frames cached in memory that are out-of-date and need to be re-simulated.
New: DOP networks can be set to "playback-only".
New: The Geometry ROP, Dynamics ROP, and Output DOP now have a Background render option to launch rendering in a separate hbatch process. The background process shows up in the Houdini render scheduler.
New: The Data Only Once DOP only attaches data/solvers to an object once, no matter how many paths through the network connect them. This can speed up cooking of certain DOP network topologies.
New: The File DOP and Data DOP now have an option to create intermediate directories when writing files.
New: The Static Object DOP has parameters for specifying a group in the source geometry, and to force recooking the source network in solver sub-steps.
Changed: DOP networks now terminate in an Output node. This is intended to replace the use of the display node flag, which was confusing to users. However the flag is still available as the orange "output" flag. The node with the output flag now has an orange indicator ring.
Changed: The current simulation is now its own menu next to the Resimulate menu button in the lower right. Shift-click the Resimulate button to reset an out-of-date simulation. Ctrl-click the button to reset all sims, even ones Houdini doesn’t think need resetting.
Changed: DOP cooking messages in the status bar now use global frames instead of simulation frames. This is less confusing when there are substeps or the simulation starts after frame 1.
Changed: Bypassing a Merge DOP now only passes through the first input.
Changed: The Details View is now called the more consistent, if less accurate, Geometry Spreadsheet.
Fixed: Smarter partial cache eviction.
Fixed: Displaying SDFs in the viewport uses less memory.
Fixed: New Blosc compression for sim files (.sim.sc) is much faster than GZIP.
Fixed: Gas microsolvers now have more detailed performance monitor events, allowing better performance tracking of FLIP and pyro simulations.
Fixed: You can now right-click on a DOP node and choose Spreadsheet to open the details view on the node’s relationships.
Fixed: The SOP Geometry DOP now accepts ad-hoc numeric or attribute groups in the Primitive Group parameter.
Other changes and improvements:
New: The new SOP Solver can now be chained. It now has a single multi-input and now grey input, making it easier to wire and re-wire. (The old version is still available through node versioning.)
New: The Rigid Body Solver node now has inputs for microsolvers (such as SOP Solvers or POP forces) that run before or after the main solve step.
New: The RBD Packed Object node has an option to fetch a list of attributes from the source geometry at each frame. This reduces the need for SOP Solvers and Wrangles in many common situations, such as transitioning between static and active objects.
New: The Glue Cluster SOP now creates all the attributes needed by the Constraint Network DOP.
New: Added several new example files for constraint networks.
New: Constraint networks can now use the orient point attribute to specify the initial orientation of an anchor using quaternions instead of the Euler angles in the r attribute.
New: Constraint Network node now has a Use object transform checkbox.
Fixed: The RBD Object, RBD State, and other nodes now properly disable the Velocity and Angular Velocity parameters when Inherit velocity is on.
Fixed: Constraint networks can now use full paths to objects (e.g. object2/piece3) to avoid name collisions between multiple RBD Packed Objects that have pieces with the same names. Turn on Use Full Path to Object in the DOP Import SOP. This is enabled by default in the network created by the Glue Adjacent shelf tool.
Fixed: The Bullet solver now recognizes the restlength attribute for pin constraints. This behaves in the same manner as for spring constraints.
Changed: Cloth Create Seam, Cloth Match Panels, Cloth Match Seams, and Cloth Refine are now removed, not just hidden.
Hair and fur:
New tools:
New: New grooming tools based on OpenVDB fields and Stroke SOP.
Operate on hair guides.
Fully procedural and artist controllable.
Fur friendly.
New: New shelf tools include hair creation, cutting, extending, randomizing, lifting, combing.
Tool for planting specific hair roots (for example, for whiskers).
Tools work in both screen space and surface space.
Automatic handling of collision with skin.
Fast and intuitive.
Other changes and improvements:
New: The Fur Object DOP, Fur SOP, and Mantra Fur Procedural now have options to remove unguided hairs.
New: The Volume Rasterize Hair SOP has a new parameter to scale the width of the rasterized curves, and an option to ransterize the tangent.
Changed: Removed all fur painting tools that influence guides, since they were incompatible with and superseded by the new grooming tools: Comb, Comb Noise, Paint Bend, Paint Bend Noise, Paint Twist, Paint Twist Noise, and Paint Length.
Fixed: Much faster rendering of hair and fur in Mantra.
Crowds:
New: Model agents at the geometry level using packed primitives.
New: Procedural behavior using new state machine DOPs.
New: Blends animation clips on state changes.
New: Individual LOD and material overrides.
New: Shelf tools for setup.
New: Terrain adaptation, collision avoidance, and foot placement.
New: Native interaction with RBD/Bullet, fluids, grains, and particles.
New: Visualization options.
New: Transition agents to heroes and back.
New: Alembic export.
Animation:
Workflow:
New: Animation editor (formerly the Channel editor) user interface improvements.
Higher quality curve display.
Auto-slope.
Channel snapshots.
Context menus and hotkeys.
Channel color options.
Improved Scale Handle Tool (renamed to Box Handle).
Channel List UI revamped, expand/collapse vector component and nodes.
Panel Toolbar revamped.
Color scheme support for the 3 default themes.
Custom channel colors using a Python callback.
New: Animation layer mixer with dedicated CHOP and simple UI.
Fixed: Faster CHOP cooking.
Performance:
Fixed: Bone display 12× faster.
Fixed: FK/FBX 6.5× faster.
Fixed: Alembic playback 3× faster.
Fixed: Motion capture playback 7× faster.
Fixed: Character deformation 3× faster.
Fixed: Simpler toon character 10-20× faster.
Lighting and rendering:
General:
New: Simplified Mantra node parameter layout organizes parameters much more clearly, emphasizing the most important controls.
New: New "Mantra user guide" content in the rendering chapter.
New: The Render menu and render node interface now have separate Render to MPlay and Render to File items to allow previews without messing with the output filename.
New: The pathmap hbatch command lets you map one directory to another. The command manipulates the value of the HOUDINI_PATHMAP environment variable.
Changed: Mantra licensing is now per-machine, not per-CPU. No matter how many copies of Mantra are running on a machine, it only uses one license.
Render view:
Changed: Procedural shaders are now cached.
Changed: The render node used in the render view now defaults to using all processors but one. This should improve user interface interactivity while using the render view.
Fixed: The background images in the Render view and Composite view panes now work with HDR images.
Lighting and shading:
New: Powerful new Pelting and Layout tools.
New: Interactive UV Flatten workflow.
New: Distortion visualization.
New: You can now use patterns (for example hero*) to set links to objects in the Light Bank.
New: New Mantra Surface Shader. Added roughness map. Reorganized interface. Parameters are now grouped with their maps. Removed Fresnel Style, exposed SSS Multi Mode. The Emission Illuminates Objects parameter now works, instead of always being on.
New: Material Style Sheets let you assign materials to disk and nested packed primitives, Alembic face sets, locked OBJ assets, and individual crowd agents.
New: New Find Materials tool lets you click geometry in the viewport and open the parameter editor for that geometry’s material. This tool reuses existing floating parameter editors by default, use ^ Ctrl + to open a new one.
New: New versions of the Surface Model and PBR Specular VOPs with roughness instead of angle controls.
New: New blosc option for .rat compression is slightly faster but less space efficient than the default gzip compression.
Changed: Changed the default marble material to work better with normal geometry.
Changed: Changed the default pre-filter ratio on the Indirect light to 1.
Fixed: Faster loading of packed primitives, faster display of Alembic geometry.
Fixed: Better energy conservation and sampling in the hair BSDF and Hair Model VOP.
Fixed: Lights can now be labeled as sss contribution.
Developer: Added Verify BSDF surface node to test and visualize the sampling of a cvex_bsdf function.
Rendering:
New: Separate sampling controls for direct and indirect rays.
New: New pixel filtering capabilities.
New: Common "extra image planes" are available as convenient checkboxes in the render node interface.
New: For each "extra image plane" in the Mantra render node, there is now an option to exclude the plane when generating deep camera maps (DCM).
New: New "extra image plane" types contain useful information for debugging performance problems: ray:nts, ray:nets, ray:nprims, and ray:nobjs.
New: Render asset procedurals.
New: Attributes on packed primitives are now available in shaders using the renderstate function. For example, if the packed primitive has a Cd attribute, you can get the value using renderstate("packed:Cd", PackedCd).
New: The Render points as parameter on objects and the Mantra render node now supports rendering points as spheres.
Changed: Disconnected points now render as spheres by default, instead of circles, and the pscale attribute is now treated as radii by default, instead of diameters. This can be 50× faster than rendering sphere primitives and use significantly less memory. To get the old behavior back, use Render points as (Mantra) and Treat point scale as diameter instead of radius.
Changed: The flatten procedural setting in Mantra is now on by default.
Fixed: Much faster fur rendering.
Fixed: GGX lighting model gives much better results than Blinn with little time difference.
Fixed: Faster Mantra startup.
Fixed: Fixed ray-traced sub-surface scattering.
Fixed: Faster BVH construction.
Fixed: Ray-traced geometry deformation motion blur is significantly faster.
Fixed: The PrePost render node now works if executed inside a subnet with single node rendering on.
Fixed: When Mantra renders packed primitive fragments, it copies attributes from the packed primitive onto the geometry, so velocity blur on fragments will work. Other packed primitive types will not work this way since they are rendered as instances.
Command-line utilities:
New: Mantra can now read compressed IFD files (with a .gz or .sc extension). Mantra now uses Houdini’s file system plug-ins, so you can specify IFD files opdef:, op:, or even http: protocols.
New: iautocrop crops out pixels less than a threshold by changing the image’s resolution or data window (preserving compression and metadata such as comments and NDC matrix). This is useful for cropping empty black space around an image.
New: Added two utilities for working with LUT (color look up table) files. ilutinfo prints general information about a LUT file. ilutcomp combines two LUT files into a single file.
New: The ilut utility now accepts the "magic" filenames srgb, rec709, and gamma=x.y to generate the described LUTs.
Other changes and improvements:
New: New render properties.
Render Visibility contains a category pattern to control the visibility of an object to different named ray types. This replaces the existing vm_phantom and vm_renderable properties.
Volume velocity quality controls Mantra’s subdivision quality for ray traced volume velocity motion blur.
Flatten Procedurals helps resolve render-order level of detail issues when procedural geometry shares subdivision or displaced geometry. This can affect Alembic and other packed geometry types.
Ray Tracing Curve Bunch Size controls the number of curve segments bunched together when building the ray tracing accelerator.
Enable Oriented BVH Construction tweaks the ray tracing tree builder to better align with curve geometry in the scene (if any).
Depth of field aspect ratio controls anamorphic depth of field.
Properties corresponding to object transformations, such as shear, pivot, offset, and pre/post rotations.
New: The HOUDINI_RIBTEMP_DIR environment variable specifies the directory for intermediate files (.sl and .err) when compiling SHOPs to RSL.
Changed: The default camera aperture was changed from 41.2136 to 41.42136. New cameras will have a slightly different field of view than cameras created with older versions.
Changed: Removed support for fog3d and texture3d shader workflows. Use volume rendering instead.
Fixed: OpenEXR 2.2 support. The Mantra ROP supports OpenEXR’s DWA compression method. The 31 character limit on channel names has been removed.
VEX and VOPs:
VOPs:
New: New method for defining inputs and outputs on VOP subnets/assets using the Parameter and Ramp Parameter nodes with their Scope set to "Subnet connector".
New: New Point in Group node.
New: New Advect by Volumes VOP for accurate advection through velocity volumes governed by a CFL condition. The POP Advect by Volumes now uses this internally.
New: The Rest Position node has a new output indicating whether the rest position was bound to an attribute.
New: You can now use parameter VOP nodes in VOP assets and VOP subnets to define inputs and outputs. Set the parameter node’s scope to "Subnet connector".
New: VOP equivalents for new VEX string functions.
Changed: The point-moving VOPs now have an Update normals if displaced option. This will recompute point and vertex normals if P is changed but N is not.
Changed: Normals will be provided to the Attrib VOP, Geometry VOP, and POP VOP if N does not exist.
Changed: Turned off automatic computation of normals in VOPs and Wranglers. The node would consider @P changed when the export was *, causing unexpected recalculation of normals.
Changed: The first two inputs of the Filter Step VOP have been reversed.
Fixed: The type properties editor has been updated to work with parameter VOP inputs and outputs.
VEX:
New: Added native vector2 and matrix2 types, two dimensional variants of vector and matrix3. If you have a parameter on a VEX operator of two floats, it will now generate a two float argument to VEX, not three floats as it did before.
New: String and array slicing
"hello"[3:4] == "lo"
New: Support for Python-style "raw strings" that don’t require escaping special characters. For example r"c:foo".
New: New array functions: sort, slice, reverse, find, append, pop.
New: New string functions: chr, ord, slice, split, append.
New: New spline variants take arrays of key positions and values, and generates a smooth curve even if the keys are not evenly spaced.
New: New group support in getbbox, getpointbbox, intersect, intersect_all, minpos, pcfind, relbbox, relpointbbox, and xyzdist functions. The expandprimgroup and expandpointgroup functions convert a group pattern into an array of primitive or point numbers. pcfind and nearpoint now support point group masks.
New: New setattribtypeinfo function changes attributes into vectors or quaternions.
New: Added VEX functions for sampling probability distributions. The names of these functions all being with sample_. For example, /vex/functions/sample_distribution_cone. These distributions are also available in the Attribute Randomize SOP.
New: vcc -v or vcc --version` will print the version number.
New: vcc can now read IFD from stdin by using - as a filename.
New: Added #pragma hint parm invisibleinput to hide an input from newly created VOP nodes when using #pragma optable vop.
Changed: The OpInput bindings now opinput:n instead of op:. This VEX functions using these bindings to properly handle multiple outputs.
Fixed: More support for structs and classes.
Fixed: Optimized handling of variadic arguments. This has a noticeable effect in the CVEX BSDF shader which has a large number of variadic arguments.
Fixed: CVEX support for array binding.
Fixed: Optimized compiler.
Fixed: vcc now properly handles #pragma hint hidden on parameters.

Houdini Changelog

What's new in Houdini 17.5.141

New in Houdini 17.0.352 (Oct 19, 2018)

New in Houdini 16.5.439 (May 10, 2018)

New in Houdini 15.5.523 (Jul 11, 2016)

New in Houdini 15 (Jul 11, 2016)

New in Houdini 14 (Jul 11, 2016)

New in Houdini 12.1.33 (Aug 17, 2012)