Physical Material vs. VrayMtl

[henning]

Hi!

A few questions regarding the Physical Material:

- Is it less efficient to use the Physical Material that ships with 3ds max comapred to the VrayMtl?
- Especially regarding Coating. Is it a stupid Idea to use this insted of a VrayBlendMtl setup?
- Is GGX used for the reflections?
- Which of V-Ray's SSS methods is used for the SSS?

I couldn't find anything about this in the V-Ray docs.
If I missed it, just tell me it's there

Cheers
Henning

[RobH22]

I'm surprised no one answered this. I've been searching for some more advanced chatter about the '3ds Max Physical Material' as it relates to VRay. I watched a tutorial by Zap today and he said always use a 'Physical Material' to connect OSL components to. I was previewing and working in the Vray 5 IPR viewer and everything was working perfectly. I've always thought that I had to use a VrayMtl for "any" texture that I built. It appears that's not the case.

This post ( https://forums.chaosgroup.com/forum/...33-3dsmax-2021 ) talks about 'Physical Material' and lists support for multiple aspects of it as well as listing things about converting it. What I can't seem to discern is if I need to convert it or not or if I can use it in lieu of the VrayMtl anytime I want. I can do some testing to answer some of these questions but I was hoping to find some definitive documentation.

[gandhics]

AFAIK, Physical material is less optimized. So, it will be slower to render. But, VRay support Physical material pretty well.
SSS-wise, it is still a little bit of moving target on Physical material side.

[matanov]

Changsoo is right here, Physical Material is still not optimized for rendering and it will be slower when comparing to VRayMtl. We are planning to make it render just as fast, but we haven't got there yet.

For layered materials VRayBlendMtl is the best choice when you have complex blend scenarios, while the new Coat layer in VRayMtl is a simpler and faster solution for just adding an extra reflection layer.

We are also working on making the VRayMtl be more "realistic" in the viewport.