Empty Space Skipping and Empty Space Skipping and Occlusion Clipping for Occlusion Clipping for Texture-Based Volume Texture-Based Volume

RenderingRendering

Wei Li, Klaus Mueller, Wei Li, Klaus Mueller,

Arie KaufmanArie Kaufman

Stony Brook UniversityStony Brook University

20032003

HighlightsHighlights

Accelerate texture based rendering by Accelerate texture based rendering by skipping invisible voxelsskipping invisible voxels

visibility order of partitioned subvolumes visibility order of partitioned subvolumes using orthogonal BSP treeusing orthogonal BSP tree

empty space skipping providing 2 to 5 empty space skipping providing 2 to 5 times faster renderingtimes faster rendering

empty voxel = transparent voxelempty voxel = transparent voxel occluded voxelsoccluded voxels

SubvolumesSubvolumes

partition volume dataset into partition volume dataset into subvolumessubvolumes

group voxels in similar/close position group voxels in similar/close position and transfer function domain (densities and transfer function domain (densities & gradients) into same sub-volume& gradients) into same sub-volume

subvolumes comprised of invisible subvolumes comprised of invisible voxels are skipped for renderingvoxels are skipped for rendering

organize remaining subvolumes into organize remaining subvolumes into orthogonal BSP treeorthogonal BSP tree

Opacity MapOpacity Map

occluded voxels determined occluded voxels determined using early ray termination using early ray termination with orthogonal opacity with orthogonal opacity mapsmaps

- map orthogonal to the - map orthogonal to the major axis of dataset that's major axis of dataset that's most parallel with view most parallel with view plane, with two axes of map plane, with two axes of map parallel to other two axesparallel to other two axes

ResultsResults