light masking with delayed load primitives

[agelosc]

Hi all,

 

I'm bringing in large alembic files for rendering with Mantra PBR. One of the primitive attributes within the alembic is imported in the shader to switch between two surface model outputs. One for opaque and one for transparent objects. I also have two lights, one for each type of object. If the alembic is imported as houdini geometry, all is good. I can group the transparent objects and with the objectMerge node use light masking on the geometry node. Easy peasy.

 

However if I were to import the almebic as delayed load primitives, I can no longer use groups and objectMerge nodes. Is there any other way to make this light masking with delayed load primitives? Possibly within the shader, or maybe fake the reflections/refraction model since my "transparent" light is just an environment map?

 

If you could point me in the right direction it would be great help,

Thanks in advance.

 

 

 

 

 

 

 

[agelosc]

If anyone is interested I think I solved this using the light contribution flags on the lights. 

 

I deactivated the refraction component on my main light (for solid objects)

I used Ray Tracing Background rendering mode on the other light (for transparent objects).

Finally on my shader I deactivated reflect lights on the surface model node for the transparent objects leaving only reflect objects on. 

 

Using Ray Tracing Background on the appropriate light seemed to be key in all this. The details of why this works is beyond my understadning but I hope it helps.