Ambient Occlusion for Particles Encode global information in textures for use during rendering

Computes level of obscurances

Results Movie 1 (show off some data sets)Movie 1 Movie 2 (use with direct lighting and shadows)Movie 2

Precomputation Time and Memory Using 20 R14K processors on an SGI Origin 3800 (muse.sci.utah.edu). Textures were 16x16 with 49 samples per texel. 955, min. 233 MB 952, min. 232 MB 543, min. 132 MB 7,157, hours 1,747 MB Fireball Bullet Foam

Impact on Performance 10% slower than direct lighting alone. However, using only the ambient occlusion values can yield as good as or better performance than direct lighting alone. Direct lightingDL with TexturesTextures w/o DL Fireball f/s14.97 f/s16.75 f/s Fireball f/s9.59 f/s10.16 f/s Cylinder f/s12.15 f/s13.37 f/s Cylinder f/s10.94 f/s11.75 f/s Bullet f/s25.59 f/s28.79 f/s Bullet f/s25.71 f/s28.41 f/s

Images Direct Lighting only Direct lighting with ambient occlusion textures Ambient occlusion textures only Cylinder 22Bullet 6Fireball 11

Impact on Performance 10% slower than direct lighting alone. However, using only the ambient occlusion values can yield as good as or better performance than direct lighting alone. Direct lightingDL with TexturesTextures w/o DL Fireball f/s14.97 f/s16.75 f/s Fireball f/s9.59 f/s10.16 f/s Cylinder f/s12.15 f/s13.37 f/s Cylinder f/s10.94 f/s11.75 f/s Bullet f/s25.59 f/s28.79 f/s Bullet f/s25.71 f/s28.41 f/s

Ingredients for Edges Image buffer Depth buffer Edge detection kernel Threshold for zero crossings 8 Laplacian kernel

Movies Movie 1 (Varying the threshold and changing the view point and field of view)Movie 1 Movie 2 (Time varying data)Movie 2

Performance WithoutWithSlowdown A18.00 f/s17.52 f/s2.63% B2.250 f/s2.222 f/s1.25% C2.259 f/s2.225 f/s1.51% D1.185 f/s1.172 f/s1.05% E2.720 f/s2.665 f/s2.02% A BC DE

Silhouette and Ambient Occlusion Examples