Stefan Gustavson has developed a distance transform method that takes an anti-aliased alpha map as input and computes a distance field with accurate sub-pixel resolution, without the need for a 4K+ binary alpha map—a modestly sized alpha map rendered with proper AA is enough. In 2007, Chris Green at Valve presented a method for crisp, anti-aliased real time contour graphics based on distance map textures. The method is very useful, but all classic distance transform methods use binary input images and therefore require almost insane resolutions to yield a good enough distance map for this application. A pre-publication write-up and GPL source code is available.
Oct 06, 2009 | Category: Developers •