I'm not quite sure I understand the thread here, but reading it gave me an idea...You could write a phython script to enable you to select an MT5 file, and a bunch of materials in your figure, and it would apply that MT5 file to those materials. The code to do this is actually enbedded in the RealSkinShader, and it might be a neat tool to have. Would get around the complete absense of any phython methods to modify the mat room nodes.

Creator of PoserPhysics
Creator of OctaneRender for Poser
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