Matte reflections + bump

[Kameleon]

Hi there, I need help with a matte reflections shader that also has bump(only reflections appear on alpha channel). I've sucessfully created one using Max's Matte/Shadow but I would like to know how to do it with a pure mentalray shader if possible. Thanks in advance.

[mustan9]

I don't understand what you want to do.

What is a "matte reflection"? Are you talking about a reflection pass?

What do you mean by "only reflections appear on alpha channel". Reflections are a RGB value and don't have an alpha component. You can use the alpha channel from a transparent pass, but usually when you composite a reflection pass you just screen or add it.

"I've successfully created one using Max's Matte/Shadow". How did you create a reflection pass with a shadow matte?

I think what your asking is how to do a shadow pass in MR.

1) Click the object properties for the objects in the scene (except the floor), and disable "visible to camera".
2) Assign a material to the floor that is 100% self illuminated, and has a shadow/light falloff in the diffuse channel.
3) Render a frame. You don't need GI or FG.

That's the easiest way to do a Shadow Matte pass in MR. There are more complex approaches then that.

[Kameleon]

Maybe this helps...

RGB Channel:
http://dimensao3.com/al/stuff/matte_rgb.jpg

Alpha Channel:
http://dimensao3.com/al/stuff/matte_alpha.jpg

This is the reflection of a sphere in a plane, the plane has the matte reflection shader and the sphere a normal Max material with Visibile to camera turned off. Thanks.

[mustan9]

That looks correct to me.

Is that the result you wanted? or something else?

[Kameleon]

This is the result I wanted it, and I've managed to do it like I've said, but using a Matte/Shadow material as base... I would like to know how to do it with a mentalray material or DGS as base. Thanks once again.

[mustan9]

I think I'm starting to understand.

The pool is not geometry, but the sphere's shadow, and in the shadow you want to see the reflection?

Is this correct? Because you can do that in MR.