Hello, I am getting stuck on rendering crowds. The problem is that the agent SOP is not creating primitive groups from FBX. The imported FBX subnet has the geometry tree, but the <agent>_shapelib.bgeo does not have primitive groups. This makes it impossible to apply shading to the crowd.

Can anyone help? Thanks in advance!

I'm not sure if this solves what you're asking, but an agent in a crowd won't have primitive groups available because it's packed.

If you create a quick very small test crowd and then unpack it, do you see your groups then?

If that's working then in order to apply group-based shading to packed stuff you need to use the material stylesheets, which are a little messy in 14.0, but the docs and some examples live here: http://www.sidefx.com/docs/houdini14.0/shade/stylesheets [sidefx.com]

One (simple) idea is have a different shader assignment done at the primitive-level inside your shape geometries. I've attached a file (agentShade.hip) illustrating this technique. I just have two separate shaders as a test for the hat and tops that are assigned using Material SOPs inside the hat object and the top object. These are just default clay materials that I added hue shift logic based on “packed:id”. Then to make sure that the shaders get included in the IFD stream, I changed the Mantra ROP's Rendering > Render > Declare Materials parameter to “Save All Material SHOPs”.