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Simplification of Arbitrary Polyhedral Meshes. *Presented by Shaun D. Ramsey at CGIM 2003 ra msey()cs.utah.edu http://www.cs.utah.edu/~ramsey/research. Motivation. Model Size Interactive/Hardware Rendering Editing Modeling Programs Transmission. Level of Detail (LOD)
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Simplification of Arbitrary Polyhedral Meshes *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
Level of Detail (LOD) Progressive Meshes (PM) Edge Collapses Triangulate Polygons Previous Work 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
For All Edges Compute Error Choose Minimal Error Error Metric Dot Product Test Add Threshold Edge Selection
Triangles Quads N-sided Polygon Normals B B B A A A A = p - p ; B = p - p i-1 ii+1 i
Pre-computation Random Selection Single Selection Refined Edge Selection
Half-edge Full-edge Vertex Selection
Half-edge Full-edge Vertex Selection
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 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