The attached piccie shows the Preview material of a pair of shoes I have, part of the AO6 Hysteria set from Al3D. Instead of being a normal PoserSurface shader, it's a Light shader.

This causes a problem with a D3D Firefly Render script that I like to use. Looking at the code, I found that this script expects to find a Displacement node on every surface material, and it crashes when it gets to these shoes because a Light shader has no Displacement node.

I can't find any way to get rid of that Light shader and put a proper PoserSurface shader in its place. Does anyone know how to do this, please?

You should probably ask D3D about this.... it's fairly easy to insert an
exception-catching line in a Python script, but I expect he has a good
reason for using displacement in each case.

Thanks David... yes, that's one way of looking at it. But I thought the problem was the wrong type of shader on the Preview material, rather than D3D's script.

As a workaround in the FireFly Render script, you can set the variable noTest to 1, then the material nodes are not tested for displacement maps. The script has no exception catching there, because I simply did not expect such a case.

To fix the material, edit the Poser file and just remove the whole shader tree from that preview material.

You can also delete the preview material completely from cr2 (or any file to tell the truth). Poser will re-create the preview zone when the item is loaded into the scene. And this should set it back to normal material zone parameters.

Thank you for your help... the script is working with those shoes now, and I'll get round to fixing the cr2 later.