I have an object mesh in Maya 2011. I am trying to achieve a cutaway-effect such that I can use a sphere to cut away (or occlude) part of the object without the sphere being visible. I want to progressively reveal the entire object this way, so I don't want to actually cut or modify the object.
I have tried a sphere with 'use background' applied as the shader, but this only works if the sphere is behind the object (in relation to the camera position). If the edge of the 'use background' sphere gets between the object and the camera, the sphere shape becomes visible in the parts of the object that are occluded. I am essentially left with a round 2-D cutout of the object.
I am trying to cut away (or hide) the part of the object facing the camera and leave a spherical cutout without the sphere being visible at all. I would like to animate the size of the sphere to make the cutout smaller or larger.
I hope this is not too confusing an explanation of what I hope is a simple problem. Any advice would be greatly appreciated.