Well for the same reason sss is a challenge in the P5 node system, I think a dirtmap shader would be very difficult. The main issue is that in the mat room, you build a network for a single pixel - and that pixel doesn't know about any other pixel (so it doesn't know if it's next to a pixel where the normals cross). An option would be to build a python script to run through the geometry and build a "dirt" map (as a jpg), that could then be incorporated as a map in the mat room. Another option would be to export the model to another package - back the dirtmap to a jpg, and import back into P5.

Creator of PoserPhysics
Creator of OctaneRender for Poser
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