A BrickMap is a good way to speed up your render times if you have a complicated environment that also has a moving camera shot. By creating a BrickMap you no longer have to calculate the occlusion on each frame;it simply references the BrickMap file. You will want to wait to create a BrickMap pass until you have finished modeling your set,as you can’t make any adjustments or changes to your set once you create the BrickMap,or else you will have to re-create it.

OK,let’s start: Open your environment file.
2.Make sure the file has been cleaned up.Check for:
• Double sided
• Subdiv scheme
• Normals facing out
• Delete history
3.Go to Window>Rendering Editors>Renderman>Shared Geometric Attributes
• Click [Create]
• Click [Edit]
• Add the RenderMan setting [Dice Rasterorient] and un-check the check box to off. (This ensures even tesselation of the scene regardless of Camera position)
• Select all of the polygon geometry in your scene and click [Attach]
4. Create a new RenderManENV light from the features tab in the RenderMan render globals.
5. Set the settings to roughly:
• Shadowing = colorbleeding (or occlusion).
• Sampling Mode = sampled
• Samples = 5 2 or higher for production quality ( 024 is production quality)
• Max variation = 0 or .Zero will be the best looking but will take a long time to render.
6. Still in the features tab click the checkered Icon next to the Bake field to create armanMakeGlobalDiffuse3dPass.

Download pdf How to Create Point Cloud and Brickmaps for Occlusion Passes