Method and system for improving shadowing in a graphics rendering system
Patent 6252608 Issued on June 26, 2001. Estimated Expiration Date: October 22, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A system for improved shadowing of images using a multiple pass, depth buffer approach includes rendering a scene from the perspective of a light source to construct a shadow depth map in a rasterization buffer. The system computes depth values for the two nearest geometric primitives to the light source for pixels, and stores these depth values in the rasterization buffer. Once the shadow map is constructed, it is stored in shared memory, where it can be retrieved for subsequent rendering passes. The two depth values for each element in the shadow map can be used in combination with a global bias to eliminate self-shadowing artifacts and avoid artifacts in the terminator region. The system supports linear or higher order filtering of data from the shadow depth map to produce smoother transitions from shadowed and un-shadowed portions of an image. In addition, the system supports the re-use of the shadow map and shadowed images for more than one frame.
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October 22, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
