How to render a mask of an object, which occludes parts of the scene? (but which itself is not rendered)

[Alexx31]

I need to render environment, which is later occluded by another object.
I can't render the front object, too, because I need to be flexible with the background.
But it would be great, if I could render a mask of it within the same rendering as render element, which I can use later to compose both parts together.

Is there a way?

Thanks

[vladimir_krastev]

Hi if I understand you correctly you want to render a scene without the front object and then render the object with scene environment/shadows and be able to add it later in post?
If this is what you are trying to do you can use the V-Ray properties (select object->right click->v-ray properties) and set it as a matte object.

Here is the docs page about this: https://docs.chaos.com/display/VMAX/...atteProperties

I'll be here if you need further help or if matte object is not what you are after.