Matte scene rendering

[Mikhalenko]

Hello,

We are currently working on an animation with some VFX and have a question about how to correctly render a layers. We use the xRef system in 3ds Max, so in our HERO file we assemble different parts of the shot, and the VFX also come separately. Our question is how to make some parts of the scene become matte objects while keeping their materials. We are rendering water and need it on a separate layer with the visible scene in refraction and reflection while in render we need to see only water with black alpha outside it

[hermit.crab]

Sounds easier to use LPE's to get only the water's RGB and set the Alpha contribution of all other objects to 0 (via a VRayMtlWrapper). Check the attached scene for reference.

If I have misunderstood something, do clarify and attach a sample scene.

[Mikhalenko]

Sounds easier to use LPE's to get only the water's RGB and set the Alpha contribution of all other objects to 0 (via a VRayMtlWrapper). Check the attached scene for reference.

If I have misunderstood something, do clarify and attach a sample scene.

Can you please resave sample scene for max 2022? problem with MtlWrapper, that it need to be applied on object with base material, but it's not possible for big scenes

[hermit.crab]

Here you go.
You can use the V-Ray properties as well. A simple script can do the job easily.

[Mikhalenko]

Here you go.
You can use the V-Ray properties as well. A simple script can do the job easily.

Thanks. I see that you a bit misunderstood my request. What I need to do is same as on screenshot, but where on render only water surface appear, with all refraction visible (like checker texture under water), and rest needs to be black with black alpha. I guess I need just use Render Mask option in vray

[hermit.crab]

The LPE element (VRayLightSelect) in the provided scene should be identical to the "Selected" render mask.