UTILISING OF BRUSH STROKING TECHNIQUES IN THE GENERATION OF COMPUTER IMAGES

摘要

Abstract UTILISING OF BRUSH STROKING TECHNIQUES IN THE GENERATION OF COMPUTER IMAGESA form of " brushing " a computer graphic image is disclosed. The method includes brushing a simulated brush stroke along a path (4220) in a computer graphics image by converting the path (4220) to a series of corresponding line segments (4222); determining a current convex brush edge of the path (4220); determining a series of substantially equally spaced points (4243, 4244, 4245) along the convex edge; determining corresponding parametric points along the path (4220) ; and utilising the parametric points to place brush template structures (4246, 4247, 4248) in the computer graphics image. In a first refinement, the opacity channel is combined such that the maximum of a current brush template opacity value and a current computer graphic image opacity channel value becomes the new current computer graphic image opacity channel value. In a second refinement, the opacity channel is combined such that the minimum of a current brush template opacity value and a current computer graphic image opacity channel value becomes the new current computer graphic image opacity channel value. In a third refinement, the computer graphic image further comprises a footprint channel which is set when each pixel is composited and the opacity channel is only composited with the computer graphic image opacity channel when the footprint channel is not set.(Figure 285)