Abstract: An occlusion culling system is provided. In various embodiments, the occlusion culling system can combine a hierarchical object space tree with image space occlusion queries to reduce the number of occlusion queries that are issued to a GPU. In various embodiments, the occlusion culling system can enable culling of dynamic objects, identification of sections of a hierarchical tree representing objects to be rendered, and continuous refinement of the object hierarchy. The occlusion culling system can perform further refinements to reduce the number of occlusion queries that are issued to the GPU during rendering of computer graphics.