Vector Texture Maps on the GPU
Nicolas Ray, Thibaut Neiger, Bruno Lévy, Xavier Cavin · 2006
Figure 1: Vector Texture Maps applied onto an object. The ACM logo is represented by four gradient shaders, combined by VTMs. By indexing characters in a font represented by a compressed VTM (that uses 128 KB), the anti-aliased text on the paper roll only uses 8 bytes per character (two RGBA texels). Performances are 54 FPS (3DLabs Wildcat Realizm 200). This paper presents VTMs (Vector Texture Maps), a novel representation of vector images that can be used as a texture by the GPU for real-time rendering. A VTM decomposes texture space into different regions, represented in an analytic way, by a set of implicit degree 3 polynomials. Each region can be rendered by a different fragment shading function. Accurate anti-aliasing is performed in real-time, based on an estimate of fragment coverage. As a consequence, infinite zooming can be applied without any pixel discretization artifact. Based on a hierarchical data structure, our representation has low memory requirements. Its versatility is demonstrated in various settings, including a font engine completely implemented in the GPU.