Patent ID: 6184857
Filing Date: 2001-02-06
Classification: G06T

Abstract:
A computer-implemented method of rendering an image of smoke or clouds in an image generator for display of pixels on a display device, said method comprising the steps of:modeling the smoke as a sphere having nonuniform smoke density, and that is comprised of a center point in three-dimensional model space, a radius, and set of parameters defining its nonuniform density and color;transforming the center point to screen coordinates;transforming the radius to a screen coordinate radius;generating a bounding polygon that surrounds a projection of the sphere in screen coordinates;clipping the bounding polygon to boundaries of the display device; andfor each pixel in the image, rendering a smoke effect by:testing if the pixel is within the bounding polygon;computing an equivalent translucency factor for the smoke at the pixel based upon location of the pixel with respect to the transformed center point, the screen coordinate radius, the set of parameters defining its nonuniform density and color, and penetration depth through the smoke; andcomputing the smoke effect for the pixel based upon the equivalent translucency factor.