Realtime Rendering SubSurface Scattering CSE 781 Prof Roger

Real-time Rendering Sub-Surface Scattering CSE 781 Prof. Roger Crawfis

Subsurface Scattering: Translucency l Light enters and leaves at different locations on the surface l bounces around (scatters) inside

Subsurface Scattering: Marble

Milk vs. Paint

Skin

Real-time Rendering Image-based Rendering CSE 781 Prof. Roger Crawfis

The graphics pipeline The traditional pipeline modeling animation rendering motion capture image-based rendering A possible IBR pipeline 3 D scanning

Image caching [Shade et al. , SIGGRAPH 1996] l Precompute l l As l BSP tree of scene (2 D in this case) Draw nearby nodes (yellow) as geometry Render distant nodes (red) to RGB images (black) Composite images together observer moves if disparity exceeds a threshold, re-render image

Apple Quick. Time VR [Chen, Siggraph ’ 95] l Outward-looking l Panoramic views taken at regularly spaced points l Inward-looking l Views taken at points on the surface of a sphere

The Plenoptic Function Radiance as a function of position and direction in a static scene with fixed illumination l For general scenes Þ 5 D function L ( x, y, z, , f )

More parameterizations Chords of a sphere L ( 1, f 1, 2, f 2 ) l convenient for spherical gantry l facilitates uniform sampling

IBR Modelling and Rendering l Store and access only pixels l No geometry, no light simulation, . . . l Input: set of images l Output: image from new viewpoint l l Large set of possible new viewpoints Interpolation allows translation, not just rotation l l l Lightfield, lumigraph: translate outside convex hull of object Quick. Time. VR: camera rotates, no translation Can point camera in or out