Initial
Use spheres so we only have to send a single list of vec4s over
Gather objects
Split logic into COcclusionCullingStandard
Change order, gather correctly, readback, count visible + culled objects
Reject occluded objects, tweak gather & shader
Improved gather, only select the objects we want
Shader re-write, output object depth and buffer depth for debug
Put debug spew behind convar, tweak shader
Tidy up, add CSceneObjectCullingData, add user-controllable per-camera toggle for occlusion culling
Stash shader before I re-write to use AABB
Switch to using bboxes for slightly more accurate results, hi-z mip checks