1. Feature-based Surface Decomposition for Correspondence and Morphing between Polyhedra
Arthur D Gregory, Andrei State, Ming C Lin,
Dinesh Manocha, Mark A Livingston
University of North Carolina at Chapel Hill

2. Highlights Empower animators to create a visually pleasing morph
Simple user interface
General

3. Previous Work Kanai et al. [1997] DeCarlo and Gallier [1996]
Galin and Akkouche [1996]
Lazarus and Verroust [1994]
Kent, Carlson, and Parent [1992]
Kaul and Rossignac [1991]
Wyvill [1990]

4. Overview Two Input Polyhedra Edit trajectories User Interpolate
Morphing sequence
Specify
Correspondence
Compute merged
polyhedron

5. Correspondence Specification

6. Correspondence Computation
Feature-Nets decompose input polyhedra into morphing patches
For each corresponding Morphing Patch pair:
map both onto a 2D polygon
merge the vertex-edge graphs
reconstruct the facets

7. Correspondence Computation
A (Igloo)
B (House)

8. Correspondence Computation
Patch A
Patch B
Extremal Vertices

9. Mapping
Patch A
Patch B

10. Mapping Desiderata

11. Merging
Patch A
Patch B

12. Reconstruction

13. Completed Correspondence

14. Morphing Trajectory Specification

15. Analysis Computation time = O(K*[m+n]) K = max{log Q,Q}
m = vertices in A
n = vertices in B

16. Implementation Implemented in C++
Uses OpenGL and Tcl/Tk libraries for display and user interface.
Interactive user interface on SGI and PC systems

17. Performance Models Igloo-House Triceratops-Human Human Heads Donut-Cup
Triangles , , , , ,096 8,452
Output
Triangles
Morphing
Patches
User
Time
Time to
Compute
Merged
Polyhedron
, , ,701
~5min ~6 hours ~3 hours ~4 hours
<1sec min sec min

18. Ongoing Efforts
Remove restriction that the chains of the feature net must lie on edges of the models
Do not require the user to specify a connected feature net
Provide better control of the model’s shape during the morph

19. Ongoing Efforts Remove restriction that models must be homeomorphic
models can change topology during the morph
Extend to include textured objects
currently interpolate only normals and vertex color

20. System Architecture

21. Conclusion Empower animators to create a visually pleasing morph
Simple user interface
Compute correspondence through surface decomposition
General