04/10/2003
15-462 Graphics I
8
Elements vs. Patches
•Analyse transport from patch onto
elements
•Do not analyze element-to-element detail
•This means
–Compute form factors from elements to
patches
–Do not compute form factors from patches to elements
–Use weighted patch to
parent-of-element
–Complexity O(m ¢ n) for m elements, n patches
•Typically substructured areas
–Near lights
–Shadow boundaries