Advanced Micro Devices, Inc.
DEPTH BUFFER PRE-PASS

Abstract:

Systems, apparatuses, and methods for implementing a depth buffer pre-pass are disclosed. A rendering application uses a binning approach to render primitives of a virtual scene on a tile-by-tile basis, with each tile corresponding to a portion of the screen. The application causes a depth buffer pre-pass to be performed for the primitives of the tile before a pixel shader is invoked. During the depth buffer pre-pass, only the depth part of the virtual scene is rendered to determine which pixel samples are visible and which pixel samples are hidden. Then, the scene is redrawn, but the pixel samples that are hidden are not sent to the pixel shader. In cases where a relatively large percentage of primitives overlap, this technique increases the efficiency of the rendering application since pixel shading can be avoided for the pixel samples that are hidden.