Premium
The Cone of Normals Technique for Fast Processing of Curved Patches
Author(s) -
Shirmun Leon A.,
AbiEzzi Salim S.
Publication year - 1993
Publication title -
computer graphics forum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 120
eISSN - 1467-8659
pISSN - 0167-7055
DOI - 10.1111/1467-8659.1230261
Subject(s) - silhouette , quadrilateral , tree traversal , computer science , strips , polygon mesh , cone (formal languages) , geometry , computer vision , mathematics , computer graphics (images) , artificial intelligence , algorithm , physics , finite element method , thermodynamics
The cone of normals technique for curved surface patches allows to perform various quick tests at the patch level such as front‐ or backfacing test, light influence test, and existence of silhouette edges test. For a given patch, a truncated cone of normals is constructed at creation time, which contains all points and all normal directions of the patch. At traversal time, a simple scalar product test determines whether the whole patch is backfacing or frontfacing, so that the costly step of tessellating the patch is avoided in case of patch level face culling. In addition, the technique quickly determines which light sources have no influence on a patch, and which patches have no silhouette edges. The technique can also be used for other surface primitives, such as triangular strips and quadrilateral meshes,