Patent ID: 6252608
Filing Date: 2001-06-26
Classification: G06T

Abstract:
In a graphics rendering system for rendering graphical models to a view space to generate successive frames of animation, a method for computing shadows for the frames of animation comprising:for a first frame, transforming characteristic points on a shadowing object to shadow map space, and saving the transformed characteristic points;for the first frame, rendering geometric primitives in a view volume from the perspective of a light source to compute a shadow depth map, rendering the geometric primitives from the perspective of a viewpoint to compute an image illuminated by the light source, and applying the shadow depth map to the image to compute a shadowed image; andfor a subsequent frame, transforming the characteristic points on the shadowing object to the shadow map space, computing a difference between the transformed characteristic points for the first frame and the subsequent frame, re-rendering the shadow depth map when the difference exceeds a predefined amount, and re-using the shadow depth map to compute a shadowed image for the subsequent frame when the difference is less than the predefined amount.