RfM
|
Introduction
Ribboxes and tclboxes were important features of RenderMan Artist Tools (RAT) - the
predecessor to RenderMan for Maya (RfM). Examples of how they were used can be found at
Scripting Related to RenderMan Artist Tools.
When RfM was introduced, the hooks and functionality offered by Ribboxes and Tclboxes
were replaced by |
Example 1: Selectively Disabling Point-based OcclusionFigure 1 shows a simple scene consisting of a nurbs sphere and a poly plane. An environment light, set to apply point-based occlusion, and a directional light (no shadows) have been added to the scene. Two instances of Blinn, renamed "sphere" and "floor", have been assigned to their respective objects. Note the objects show the effects of both occlusion and direct illumination.
In figure 2 the sphere does not show occlusion from the floor because the visibility the poly plane was, in effect, "turned off" during the RenderRadiosity pass and as such its micropolygon data was not baked into pointcloud generated by that pass. This was achieved by adding a ribbox to the shading group of the material assigned to the (floor) plane - figures 3 and 4.
The rib statements shown below were added to the ribbox. IfBegin "$user:pass_class == 'RenderRadiosity'" Attribute "visibility" "camera" [0] IfEnd |
Example 2: Selectively Disabling an Environment LightFigure 5 shows a scene consisting of five nurbs sphere and a poly plane. As in the first example an environment light, set to apply point-based occlusion was added to the scene. Three directional lights (no shadows) have been light-linked so that they only illuminate the central sphere. Two instances of Lambert renamed "occlusion" and "no_occlusion" were added to HyperShape. The "no_occlusion" material was assigned to the central sphere; the "occlusion" material was added to the poly plane and the other four spheres.
In figure 2 the sphere does not show occlusion from the floor because the visibility the poly plane was, in effect, "turned off" during the RenderRadiosity pass. Consequently, the micropolygon data of the plane was not baked into pointcloud generated by that pass. This was achieved by adding a ribbox to the shading group of the material assigned to the sphere - figures 3 and 4.
The rib statements shown below were added to the ribbox. IfBegin "$user:pass_class == 'RenderRadiosity'" Attribute "visibility" "camera" [0] IfEnd |
© 2002- Malcolm Kesson. All rights reserved.