1. A method for simplifying an occluder representing 3D graphics data, the method comprising: voxelizing the graphics data corresponding to one or more 3D objects; generating a plurality of planes to intersect the voxelized graphics data; evaluating intersections between the planes and the voxelized graphics data to identify corresponding slice polygons from the intersections; selecting a subset of the planes to maximize a correctness of a simplified occluder; and generating the simplified occluder representing each 3D object from a union of the selected subset of the planes.