Preventing object reflecting another

[dsp_418]

I'm struggling with a problem that I thought would have been much easier.

I've a scene setup as follows:

- Floor.

- Main object (let's say a sphere).

- Reflecting object (a cube).

 

I want the cube to reflect on the sphere but not on the floor. I know it's possible to control the distance of the reflection, but this doesn't work in my case as the distance both from the sphere and the floor are quite the same. Would be really useful something like the light exclude parameters where it's possible to exclude objects.

 

Any hints?

Thanks in advance.

[Andres del Castillo]

Hi, Marco.

 

I understand that you are using 3ds max. Select the floor, go to object properties, and uncheck visible to reflection/refraction. Done. The sphere reflects only the cube. Good luck!

[dsp_418]

Thank you Andres,

 

unfortunately that's not so easy as I want the floor to reflects the sphere but not the cube.

[Andres del Castillo]

Then, do the same with the cube.

[dsp_418]

I'm not sure to understand, if I do the same with the cube isn't this gonna prevent the cube to being reflected on everythnig, included the sphere?

[abhaysingh]

Hi Marco,

Interesting question.I think it is impossible to achieve this in a single render because max/vray doesn't give you so much control over reflection properties.You need to render your scene in two passes.

 

Pass1 -- go to cube object properties and uncheck "visible in ref/refrac.Now make make it matte object by changing its vray properties(i hope you know how to make matte).Render sphere and floor with cube being matte.Check affect in vray properties as well.

Pass2 -- now reverse all the changes you've done to cube & make normal object to render.Select floor and make matte object and this time don't check affect alpha in vray properties when making matte.

 

When you combine both you'll get your results.ie.

1)cube--its reflection will be visible in sphere but not in floor.

2)Sphere--it will receive all the reflection and will get reflected in cube and floor as well.

3)floor--will not recieve cube reflection but sphere will get reflected.

 

I hope this is what you wanted to achieve.Iam attaching test results of both the passes and final composited render.

[Scott Schroeder]

Hi Marco,

Interesting question.I think it is impossible to achieve this in a single render because max/vray doesn't give you so much control over reflection properties.You need to render your scene in two passes.

 

Pass1 -- go to cube object properties and uncheck "visible in ref/refrac.Now make make it matte object by changing its vray properties(i hope you know how to make matte).Render sphere and floor with cube being matte.Check affect in vray properties as well.

Pass2 -- now reverse all the changes you've done to cube & make normal object to render.Select floor and make matte object and this time don't check affect alpha in vray properties when making matte.

 

When you combine both you'll get your results.ie.

1)cube--its reflection will be visible in sphere but not in floor.

2)Sphere--it will receive all the reflection and will get reflected in cube and floor as well.

3)floor--will not recieve cube reflection but sphere will get reflected.

 

I hope this is what you wanted to achieve.Iam attaching test results of both the passes and final composited render.

 

This is exactly what you need to do. Simply render in passes. It's much easier and provides you with much more control.

[dsp_418]

Thanks for the replies.

The method suggested by Abhay Singh is good and I'm actually doing something similar right now (but not as neat as Abhay's method). Nonetheless is not very handy as I'm working on a long, time consuming animation and that means I've to render it twice. I really hoped there was a smarter solution, strange that ChaosG. didn't introduced a feature like this.