This paper by Guha et al., to appear in the 2003 ACM SIGGRAPH Symposium on Interactive 3D graphics, shows how the shadow mapping operation in the new NVIDIA GeForce4 cards can be viewed as a two-sided depth test in order to do CSG rendering efficiently. The result is an algorithm that can perform a topological sweep over an arrangement of objects in three dimensions. It also shows the first lower bounds on the number of rendering passes required for a hardware-assisted computation. (Application of the Two-Sided Depth Test to CSG Rendering. S. Guha, K. Munagala, S. Krishnan and S. Venkatasubramanian. To appear in the 2003 ACM SIGGRAPH Symposium on Interactive 3D graphics.)