M4G - A Surface Representation for Adaptive CPU-GPU Computation

Transcription

1 M4G - A Surface Representation for Adaptive CPU-GPU Computation Vision and Graphics Lab Institute of Pure and Applied Mathematics Trimester Program on Computational Manifolds and Applications November 22, 2011 Rio de Janeiro, Brazil

2

3 Manifolds-for-GPUs (M4G) Goal Surface Dynamic and adaptive CPU-GPU computation Source Scanned triangular meshes Application (e.g.) Progressive visualization

4 Manifolds-for-GPUs (M4G) Goal Considerations Surface Ongoing work Dynamic and adaptive Make several assumptions CPU-GPU computation Use many known techniques Source Scanned triangular meshes Application (e.g.) Progressive visualization The "manifold" word is used lightly

5 basic :: surface triangular mesh

6 basic :: surface halfedge structure triangular mesh

7 basic :: subdivision surface quadrangular base mesh

8 basic :: subdivision surface quadrangular base mesh Catmull-Clark subdivision

9 our goal surface

10 our goal surface simplification process base mesh

11 our goal surface 4-8 mesh base mesh

12 our goal atlas surface 4-8 mesh collection of charts base mesh

13 our goal atlas surface 4-8 mesh collection of charts II-bimba-base-wire-up.avi base mesh

14

15 problem statement surface + base mesh

16 problem statement surface + base mesh how to build a correspondence?

17 problem statement Multi-resolution structure surface Low-level in the CPU + High-level in the GPU Dynamic controllable base mesh how to build a correspondence? IV-bimba-cpu-gpu-up-down.avi

18 problem statement + correspondence

19 problem statement + correspondence chart boundaries build an atlas

20 problem statement + correspondence parameterizations: curves (1D) and interior (2D) chart boundaries finding curves over the surface build an atlas

21 finding curves over the surface first thought :: geodesics nice grid of charts

22 finding curves over the surface problem with geodesics avoiding high frequencies inconsistency through chart boundaries how to find better curves over the surface?

23 finding curves over the surface problem with geodesics corresponding boundary curve

24 finding curves over the surface work in progress :: new algorithm boundary curve based on cutting plane

25 finding curves over the surface work in progress :: new algorithm assign an "edge normal" based on the base mesh faces define cutting planes for each chart boundary (base mesh edges)

26 finding curves over the surface new algorithm :: problem solved? assign an "edge normal" based on the base mesh faces define cutting planes for each chart boundary (base mesh edges)

27 finding curves over the surface problem with new algorithm ok here computing without considering others matching all cutting planes to agree without intersection on curves is difficult (maybe even NP-Complete?) inconsistency through chart boundaries

28 building an atlas surface and curves

29 building an atlas surface and curves

30 building an atlas surface and curves parameterize curves by arc-length

31 building an atlas surface and curves parameterize curves by arc-length

32 building an atlas parameterize interior using a known technique (such as [Floater, 2003]) surface and curves parameterize curves by arc-length

33 building an atlas parameterize interior using a known technique (such as [Floater, 2003]) surface and curves parameterize curves by arc-length

34 building an atlas composed both in the M4G atlas parameterize interior using a known technique (such as [Floater, 2003]) surface and curves parameterize curves by arc-length

35 comparing parameterizations [Floater, 2003] chosen result

36 4-8 mesh base mesh

37 4-8 mesh tile (triquad: triangulated quadrangulation) base mesh

38 4-8 mesh tile base mesh chart

39 4-8 mesh tile chart 1D shared parameterization base mesh 2D separate parameterization

40 4-8 mesh tile base mesh chart

41 4-8 mesh tile base mesh chart lookup surface properties in the interior of chart

42 4-8 mesh tile base mesh chart lookup in the boundary of chart

43 4-8 mesh tile base mesh chart refinement and simplification occur in the CPU...

44 4-8 mesh tile base mesh chart refinement and simplification occur in the CPU... VI-bimba-texture-lines.avi

45 CPU-GPU coupled computation dense mesh Multi-resolution structure base mesh

46 CPU-GPU coupled computation dense mesh Multi-resolution structure controlled by the CPU base mesh

47 CPU-GPU coupled computation dense mesh tessellated by the GPU Multi-resolution structure base mesh

48 CPU-GPU coupled computation

49 CPU-GPU coupled computation footnote patch vertices can be defined vertices vertex shader controls the tessellation level of the patches specify properties of tessellated vertices tessellation control shader tessellation evaluation shader tessellator geometry shader fragment shader rasterizer pixels

50 CPU-GPU coupled computation footnote patch vertices can be defined vertices vertex shader controls the tessellation level of the patches specify properties of tessellated vertices tessellation control shader tessellation evaluation shader tessellator VIII-bimba-min-max.avi geometry shader fragment shader rasterizer pixels

51

52 applications progressive visualization

53 applications progressive visualization XV-bimba-top-down.avi

54 conclusions An adaptive surface Controlled by both the CPU and the GPU Boundary curves are still tricky Atlas storage is naïve More meaningful applications making of...

55 finding boundary curves using global parameterization as initial guess base mesh on top of domain? is it still a valid mesh? on the interior?

56 Thank You! Trimester Program on Computational Manifolds and Applications acknowledgements: