ViewDependent Textured Splatting for Rendering Live Scenes

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View-Dependent Textured Splatting for Rendering
Live Scenes

• R. Yang, D. Guinnip and S. Lai

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Goal

• A novel approach to render low resolution point
  clouds with multiple high resolution
  textures---the type of data typically from
  real-time vision systems.

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A Typical WayTriangulation

• robust 3D triangulation is a challenging
  computational problem, which means real-time
  triangulation is not yet feasible.
• It can have the side effect of magnifying
  outliers.

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Rendering Results from a Live Scene
Triangluar Mesh Rendering
Point Splatting Rendering
VDTS Rendering
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Related Work

• Qsplat in Siggraph 2000
• Surfel in Siggraph 2001
• VDTM in Siggraph 1996
• Real-time VDTM using projective textures
• in 9th Eurographics 1998
• Unstructured lumingraph rendering
• in Siggraph 2001

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Two directions in Splat

• Speed rendering in real time by using
  multiresoltuion and LOD control techniques.
• Quality Carefully balancing points sampling
  density or precisely texture mapping

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Visibility Issues

• Projecting a three dimensional object to a two
  dimensional image plane, in most cases cause
  surface elements to overlap. Such overlapping can
  cause visual artifacts when occlusions and
  disocclusions are present.

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Anti-Aliasing

• Unlike most splating algorithm, VDTS uses splats
  that are usually much bigger than one screen
  pixel. As a result, anti-aliasing for high
  resolution textures can be handled directly by
  the graphics hardware.

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Texture anti-aliasing

• Each splat has only one color
• Each splat is rendered with projective
  texture-mapping

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Visibility processing

• The visibility problem is equivalent to the
  shadow determination problem.
• Fully supported by graphics hardware

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Visibility Clipping
The visibility processing can be problematic at
surface boundary. In the presence of high
resolution depth map, we can compare the fragment
depth with the actual depth. If the difference is
too large, then we know it is likely a part of
extruding splat that should really be transparent.
The large circle represents one view, P and Q are
splats leading to inaccuracy in silhouettes.
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Results of Visibility Clipping
Bunny data set rendered with visibility clipping
disabled/enabled