Curved PN triangles

To improve the visual quality of existing triangle-based art in realtime entertainment, such as computer games, we propose replacing flat triangles with curved patches and higher-order normal variation. At the hardware level, based only on the three vertices and three vertex normals of a given flat triangle, we substitute the geometry of a three-sided cubic Bezier patch for the triangle's flat geometry, and a quadratically varying normal for Gouraud shading. These curved point-normal triangles, or PN triangles, require minimal or no change to existing authoring tools and hardware designs while providing a smoother, though not necessarily everywhere tangent continuous, silhouette and more organic shapes. CR Categories: I.3.5 [surface representation, splines]: I.3.6--- graphics data structures Keywords: curved surface, PN Triangle, hardware, real-time, surface tessellation NSF NYI CCR-9457806, jorg@cise.ufl.edu, chasb@microsoft.com, Alex@Vlachos.com, JasonM@ati.com 1 Introduction ...