Ayam description
A free 3D modelling environment for the RenderMan interface

Ayam is a free 3D modelling environment for the RenderMan interface, distributed under the BSD licence. This means that neither the author nor any contributors make money out of this software.

CSG-Modelling

· CSG (Constructive Solid Geometry): compose complex objects from primitives that are combined with boolean operations.
· The following RenderMan primitives (quadrics) are implemented: Sphere, Disk, Cylinder, Cone, Hyperboloid, Paraboloid, and Torus; additionally, there is a Box primitive.
· All quadrics may be automatically closed (missing cap surfaces generated), even if any of their parameters are not on default values.
· Primitives may be combined using Level objects (that do CSG operations) in a hierarchy.
· Ayam itself does not calculate and preview the results of CSG operations, this is done by a RenderMan compliant renderer or by the aycsg CSG preview plugin, which is based on OpenCSG. See an example rendering of the aycsg plugin.
· CSG operations are not limited to the aforementioned primitives. As long as it is guaranteed that an object is fully closed, it may be used in CSG operations.

NURBS-Modelling

· NURBS (Non Uniform Rational B-Splines): allows to model smoothly shaped objects with high accuracy.
· NURBS modelling is done by combining common NURBS curves or interpolating curves to NURBS patches.
· Combination is e.g. done using tool objects: Revolve, Extrude, Sweep, Birail1, Birail2, Skin, and Gordon. For instance: a Revolve tool object has a planar curve as child object and revolves it to a surface of revolution; the curve stays editable all the time, caps may be added automatically by simply clicking on check-boxes. Fully closed NURBS object is available as primitive to CSG!
· Revolve object with arbitrary angle of revolution; may create full caps.
· Extrude object with holes, bevels and caps.
· Sweep object implements the standard sweep operation (sweeping a cross section curve along a trajectory curve); the cross sections may be rotated automatically, so that they are always perpendicular to the trajectory; in interpolating mode, the sweep interpolates all the cross-section-curves; a scaling curve may be present that modifies the sweep further.
· Birail1 object sweeps a cross section along two rail curves.
· Birail2 object sweeps a cross section along two rail curves, morphing it into a second cross section at the end of the rail curves.
· Skin object is able to skin curves of arbitrary topology (skin an interpolating curve with 4 points with a linear NURBS curve with 2 points and a cubic NURBS curve with 10 points); in interpolating mode, the skin even interpolates all the curves.
· Gordon object creates Gordon surfaces that interpolate a network of curves.
· Cap object is able to create planar caps from curves.
· ConcatNC object concatenates a number of NURBS curves, creating fillets where necessary.
· High quality Text object creates objects based on extruded Bezier curves extracted from TTF files.

Additional Geometric Types

To complement the feature set and allow easier integration of objects from systems with other modelling paradigms, Ayam also supports:

· Bilinear and Bicubic Patch Meshes
· Poly Meshes
· Subdivision Surfaces
· Metaballs

Those objects will be imported and exported but no extensive set of modelling tools exists to modify them.

RIB-Export

· Highly acclaimed RIB-Export.
· Invoke renderers directly from a view window (including a progress meter and cancel button).
· AreaLights
· ShadowMaps
· Custom RiOptions and RiAttributes using tags.
· Texture coordinates using tags.
· Arbitrary primitive variables using tags.
· Direct support for the following RenderMan compliant renderers: BMRT, 3Delight, Air, Aqsis, Pixie, RenderDotC, Angel, and PRMan.
· Permanent Preview feature.

RIB-Import

· RIB-Import, supporting Lights, Quadrics, CSG, NURBS, PolyMeshes, Subdivision Surfaces, Transformations, Shaders, Arbitrary Options, Attributes, and Primitive Variables.

Import/Export

· Wavefront OBJ Export, supporting (trimmed) NURBS and PolyMeshes.
· Rhino 3DM Import/Export supporting (trimmed) NURBS and PolyMeshes.
· Apple 3DMF (V1.0) Import/Export supporting (trimmed) NURBS and PolyMeshes

Misc

· Easy to understand user interface.
· Full (indexed) documentation available as HTML or PDF.
· TreeView with Drag-and-Drop support.
· Custom objects that may freely implement their representations (using OpenGL and RIB) and even small GUIs to edit their type specific parameters may be written by the user and dynamically loaded at runtime.
· Scripting interface: Tcl.
· Script Objects.
· Instancing, arbitrary number of modeling views, object clipboard, independent property clipboard, console, n-level undo.

Here are some key features of "Ayam":

· RIB (RenderMan Interface Bytestream) export and import.
· Support for NURBS curves and (trimmed) NURBS surfaces, Boxes, Quadrics (Sphere, Disk, Cylinder, Cone, Hyperboloid, Paraboloid, and Torus), CSG, MetaBalls, Patch Meshes, Polygonal Meshes, and Subdivision Surfaces.
· NURBS modelling includes normal and interpolating curves as well as extrude, revolve, sweep, birail, skin, and gordon objects with caps, holes, and bevels.
· Custom objects that may freely implement their representations (using OpenGL and RIB) and even small GUIs to edit their type specific parameters may be written by the user and dynamically loaded at runtime.
· Scripting interface: Tcl.
· Misc: instancing, arbitrary number of modeling views, object clipboard, independent property clipboard, console, n-level undo