Matte problem

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

Hi,

I’m doing some product shots and I need my product to reflect the shadows on the matte ground, but also reflect some lightcards that needs to be below the ground, but the matte object blocks them. Best explained on this test image:

Is there anyway around this?

/Thomas

2

does switching off ‘visible to reflection’ in that ground plane work?
e: probably not.

3

Then the shadows on the ground doesn’t show up in the reflections in the sphere.

4

perhaps in this case render it separately? 1 with the shadow 1 with only the reflections and then edit them together in photoshop. I think there is no easy way for vray matte to let through materials from some objects and still work as a matte. defeats the purpose.

But yeah I think you already thought about it and hope for a more simple solution :slight_smile:

5

I do not believe without the use of raytype/rayswitch this kind of thing is possible. Unless you render the shadow and plug it into the opacity of the shader, but it would still be a two step process. I remember in mental ray such thing was possible.

6

Here is one solutions which could help in this situation.

0.SceneFile >
1.Assign VrayOverrideMtl to the ground-plane(matte-plane)
2.Assign new VrayMtl into Reflect Mtl slot in VrayOverrideMtl
3. Assign Falloff Map into Opacity slot of VrayMtl and change its type to Shadow/Light and switch colors (Shadow = White / Light = Black)
4.Render
matte.zip (31.6 KB)

Screenshot_4.jpg
Screenshot_4.jpg1918×1079 218 KB

7

Wow thats interesting option! Thanks for info. U using fresnell in shadow/light - is it reproducible in maya ? I need samplerInfo node?

8

Thanks Svetlozar, that looks like an option that might, I definitely have to try that out.

9

I don’t know if it would work with the dome light or gi though.

DADAL, for maya we did manage to make this work (shadow/light dir) but you have to take the light position in 3d space and specify it in the shader, which meant connecting each light to a vector node and passing that off *I don’t remember the exact process, but it wasn’t as automatic as in max.

10

It won’t work in every situation but it could be useful in that one.