I'm creating geometry on the fly via a VRAY_Procedural, setting
the shader reference on each polygon using the shop_vm_surface attribute. Since that is a reference to a SHOP node, how do I create the SHOP node?

Thanks!

mercier1
I'm creating geometry on the fly via a VRAY_Procedural, setting
the shader reference on each polygon using the shop_vm_surface attribute. Since that is a reference to a SHOP node, how do I create the SHOP node?

Thanks!

If you want to apply the same shader to the entier geometry, please look at the box procedural sample code.

Otherwise…

The SHOPs have to be pre-declared in the IFD (you can see the syntax in an IFD that has these embedded – the ray_start material block.

This might not be ideal for a procedural.

Method 1
Fortunately for you, the “old” style of attributes is also still supported (and probably will be for a long long time).

If you add the string attribute “vm_surface”, you can specify a surface shader string explicitly (or vm_displace).

Method 2
Generate multiple sets of geometry instead of trying to do it all at once. Rather than making a detail with shader attributes, why not make multiple geometry objects in mantra without any geometry shaders, but using the surface property instead?

You might find this interesting too:
http://forums.odforce.net/index.php?/topic/10781-vrayprocedural-and-material [forums.odforce.net]