Shimizu, ClementMeyer, Gary W.Laszlo Neumann and Mateu Sbert and Bruce Gooch and Werner Purgathofer2013-10-222013-10-2220053-905673-27-41816-0859https://doi.org/10.2312/COMPAESTH/COMPAESTH05/223-230A BRDF approximation is developed that is suitable for interactive color appearance design in direct lighting provided by environment maps. The BRDFs are approximated as a linear combination of cosine lobes with a fixed set of specular exponents. A nonlinear optimization routine is used to fit the cosine lobes to BRDFs appropriate for a specific color appearance design application: automotive paint. Modification and rendering of the BRDF is made possible by linearly combining prefiltered environment maps for each cosine lobe in real time.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism-Color, shading, shadowing, and texture