Is there a way to get the occluded result of a geometry in shaders?

[magneto]

Hi,

 

I want to get the normalized occluded result of a geometry in a shader so that I can use this to drive other things like apply a noise and filter the dark areas for example.

 

Something that looks like this:

 

I tried Occlusion VOP but didn't really get anything close to this.

 

I want to be able to filter the obstructed areas in the geometry.

 

 

Thanks

[Robert]

Try looking at eetu's work here: http://forums.odforc...tus-lab/page-14

A similar topic on the sidefx forums: http://www.sidefx.co...ea5e5673f2580ea

[lukeiamyourfather]

Can you post what you are getting with the occlusion node? It should be able to produce images like your example.

[magneto]

Thanks Luke, I get this:

 

 

Is this normal?

[lukeiamyourfather]

I see what you mean with the artifacts, probably coming from the surface normals. A good alternative to the occlusion node is to use a white diffuse material on the objects in the scene and the default environment light. It should come out something like this, just did a quick test with an old project with lots of geometry.

[magneto]

Thanks Luke. Can this be done inside a shader though? Because I need the color/grayscale value to drive other things, for example a ramp or other procedural textures where I could isolate certain areas like the dark areas for example.

 

So I want my shader to handle this internally. I still need to check the links Robert posted, just didn't have much time yet.

[lukeiamyourfather]

The answer is probably yes, but not sure off the top of my head. That's really what the occlusion node is for and I think it could work for what you need if you sort out the issues with the geometry like normals. Perhaps try subdivisions on the geometry if you try the occlusion node again.