Download presentation
Presentation is loading. Please wait.
1
Stable 6-DOF Haptic Rendering with Inner Sphere Trees
Stable 6-DOF Haptic Rendering with Inner Sphere Trees René Weller, Gabriel Zachmann Clausthal University, Germany IDETC/CIE 2009, Aug-Sep 2009, San Diego, CA
2
BVHs vs Voxels BVHs Voxel based algorithms Easy to build
Fast, robust and exact Complicated to compute penetration depth Not fast enough for haptic applications Mendoza et al, 2006],[ [Zhang et al, 2007], … Voxel based algorithms Fast enough for haptic interactions Independent of object complexity Memory consuming Aliasing artifacts [McNeely et al., 1999] Related Work Our Approach Details Collision Response Results Extensions Conclusion
3
Goal: Keep the Best of Both Worlds
Keep a single consistent data structures for moving and fixed objects Near constant running time Low memory usage Continuous feedback forces Related Work Our Approach Details Collision Response Results Extensions Conclusion
4
Our Novel Approach: Inner Sphere Trees
Fill the object with non-overlapping spheres Build sphere hierarchy Support for approximative separation distance and penetration volume Penetration volume defines a new approach for penalty forces Related Work Our Approach Details Collision Response Results Extensions Conclusion
5
Sphere Packing Related Work Our Approach Details Collision Response Results Extensions Conclusion
6
Hierarchy Creation Related Work Our Approach Details Collision Response Results Extensions Conclusion
7
Batch Neural Gas Clustering
w1 w2 Related Work Our Approach Details Collision Response Results Extensions Conclusion
8
Hierarchy Creation in 3D
Related Work Our Approach Details Collision Response Results Extensions Conclusion
9
BVH Traversal: Penetration Volume Queries
Penetration volume = v1 + v2 Penetration volume = 0 Penetration volume = v1 Related Work Our Approach Details Collision Response Results Extensions Conclusion
10
BVH Traversal: Proximity Queries
d1 distance < d1 Related Work Our Approach Details Collision Response Results Extensions Conclusion
11
Collision Response Part 1: Forces
Collision Response Part 2: Torques Collision Response Part 1: Forces s2red Å s2blue Pi,j niblue -niblue sjred Å siblue ftotalblue= fiblue (si, sj) = (Pi,j – Cm) £ fi fiblue=(sjredÅ siblue)(–niblue) total = (si, sj) = (Pc – Cm) £ f Related Work Our Approach Details Collision Response Results Extensions Conclusion
12
Results: Forces / Torques
Related Work Our Approach Details Collision Response Results Extensions Conclusion
13
Results: Penetration Volume
Related Work Our Approach Details Collision Response Results Extensions Conclusion
14
Results: Proximity-Queries
Related Work Our Approach Details Collision Response Results Extensions Conclusion
15
Multithreaded Time Critical Approach
Separation List Visual Rendering Thread Haptic Simulation Thread Collision Detection Thread Positions Positons Related Work Our Approach Details Collision Response Results Extensions Conclusion
16
Time Critical Traversal: Separation List
Related Work Our Approach Details Collision Response Results Extensions Conclusion
17
Expected Overlap Volume
Related Work Our Approach Details Collision Response Results Extensions Conclusion
18
Applications 12 full dynamically moving objects 3.5M of triangles
1KHz simulation rate Old Pentium IV 3GHz computer Related Work Our Approach Details Collision Response Results Extensions Conclusion
19
Conclusions Inner Sphere Trees with support for
Proximity queries Penetration volume computation Independent of object complexity Fast run time with high accuracy Accuracy loss < 1% at 1 KHz refresh rate Stable multithreaded time critical algorithm BVH-like low memory usage and consistency Continuous forces and torques => No Aliasing Related Work Our Approach Details Collision Response Results Extensions Conclusion
20
Future Work Derive exact error bounds to get the optimal number of inner spheres GPU implementation Other bounding volumes Other objects Thin sheets Deformable objects Related Work Our Approach Details Collision Response Results Extensions Conclusion
21
Acknowledgments DFG grant ZA292/1-1
BMBF grant Avilus / 01 IM U.
Similar presentations
