Simplification of Arbitrary Polyhedral Meshes
Shaun D. Ramsey*
Martin Bertram
Charles Hansen
University of Utah
University of Kaiserslautern
University of Utah
*Presented by Shaun D. Ramsey at CGIM 2003
ramsey()cs.utah.edu
http://www.cs.utah.edu/~ramsey/research
Motivation
Model Size Interactive/Hardware
Rendering Editing
Modeling Programs Transmission
Previous Work
Level of Detail (LOD) Progressive Meshes (PM) Edge Collapses Triangulate Polygons
From Sander’s Texture Mapped Progressive Meshes
The Process
Edge Selection Vertex Selection Edge Collapse
The Process
Edge Selection Vertex Selection Edge Collapse
The Process
Edge Selection Vertex Selection Edge Collapse
Edge Selection
For All Edges Compute Error
Choose Minimal Error
Error Metric Dot Product Test Add Threshold
Polygon Normals
Triangles
Quads
N-sided
A
AA
BBB
A = p - p ; B = p - p i-1 i i+1 i
Refined Edge Selection
Pre-computation
Random Selection
Single Selection
Vertex Selection
Half-edge
Full-edge
Vertex Selection
Half-edge
Full-edge
Collapse and Split
Options
Half or Full-edge Collapses Changing the Error Metric Error Threshold Percent/Number of Edges Searched Treat N-sided Polygons Differently
Threshold Differences – Maximum Simplification
256 1478 6492 137950.950 0.990 0.999 0.9999
Threshold DifferencesRemove 15000 Polygons
0.00 minimum dot product 0.99 minimum dot product
ResultsPercentage Search
Original 42 Edges 425 Edges
Results Simplification
~870k polygons ~370k polygons
ResultsLOD Simplification
871k 378k 67k
Results – Timing
Model Original Simplified Time (s)
Dragon 871414 48584 42.900
Bunny 69451 6958 4.110
Crocodile 21590 11695 3.670
Venus 4254 711 0.310
0.99 minimum dot product, search 1% of the mesh
Future Work
Selective Refinement Multi-resolution Editing Preservation of Feature Lines Surface Parameterization Surface Segmentation
Acknowledgements
Utah Graphics Group Stanford Scanning Repository Avalon
