VRayHairMtl doesn't respect Reflection/Refraction and Glossy Effects global switches

V-Ray V-Ray for 3ds Max Issues
1

As the title suggests, I just noticed that the VRayHairMtl doesn’t respect Reflection/Refraction and Glossy Effects global switches.

With Reflection/Refraction and Glossy Effects disabled (but GI still enabled) the hair material still has reflection, refraction, and specular components.
Any reason for this? I know reflection and refraction is tied to GI, but it still seems a bit inconsistent - especially with specular.

Thanks!

2

Hi Akin,

We are aware about this issue and our developers are looking into this.

3

Cool, good to know.

Thanks Tashko!

4

The hair material uses the GI rays to compute all of the above effects. There are no separate reflection/refraction/glossy rays like with a regular material.

I know reflection and refraction is tied to GI, but it still seems a bit inconsistent - especially with specular.The specular is just a portion of the reflection of lights, same as normal materials. It uses the normal calculations used to compute shadows and direct lighting.

The reflection/refraction and glossy switches were mostly added to help with preview renders to make them faster, but for the hair material, this will not really save anything as it doesn’t do extra work to compute these effects.

Best regards,
Vlado

5

Understood, but wouldn’t it make sense to have the HairMtl behave as if GI was turned off in the case of the Reflection/Refraction and Glossy Effects switches being disabled?

I guess it can get tricky since GI and Reflection/Refraction and Specular are all tied together for the shader.

6

I don’t know really. It wouldn’t make much sense to me as it would make the hair very dark.

Best regards,
Vlado