Vray Light Mtl as Surface Shader

[dariofx]

Using Vray for Maya 3 in Maya 2015 SP5, WIN 7

So, I've heard of people using the Vray Light Mtl as a surface shader.

I know that the native Maya surface shader is supported in Vray for Maya but I was wondering if there are any advantages in using the Vray Light mtl instead?

I've seen some occurrences when using the native surface shader where I'll get an "unsupported" warning message, yet it still seems to render fine.

What the the consensus here?

[Svetlozar Draganov]

Using V-Ray native nodes is always better than using external ones even if they are supported.
VrayLightMtl for example has an option for Exposure Compensation which is very useful when V-Ray Physical Cam is used.

[dariofx]

Thank you for the reply.

If I'm going to start using the light mtl as a full replacement for the native surface shader, are there any issues or gotchas that I should be aware of? How about settings? Besides changing the color of the light mtl, do I need to change any other settings to make sure it behaves like the native maya surface shader?

I appreciate the help.

[Svetlozar Draganov]

The default setting will replicate the result from the Surface Shader only the color must be adjusted.
Emit On Back Side option must be also activated if the shader is applied to a plane object.
If you have a Physical Camera in the scene it is recommended to turn on Compensate Camera Exposure checkbox.
If you want to turn the object into a light source you can do that from Direct Illumination Rollout.

[dariofx]

Ok, great.

The only thing I'm noticing now is that the vray light mtl doesn't have a "out matte opacity" option like the native maya surface shader. I use that a lot to create a black hole or cut out type of effect.

[snivlem]

use the vraymtlwrapper for that dariofx