Conference Paper

Bounded normal trees for reduced deformations of triangulated surfaces.

DOI: 10.1145/1599470.1599480 Conference: Proceedings of the 2009 ACM SIGGRAPH/Eurographics Symposium on Computer Animation, SCA 2009, New Orleans, Louisiana, USA, August 1-2, 2009
Source: DBLP

ABSTRACT Several reduced deformation models in computer animation, such as linear blend skinning, point-based animation, embedding in finite element meshes, cage-based deformation, or subdivision surfaces, define surface vertex positions through convex combination of a rather small set of linear transformations. In this paper, we present an algorithm for computing tight normal bounds for a surface patch with an arbitrary number of triangles, with a cost linear in the number of governor linear transformations. This algorithm for normal bound computation constitutes the key element of the Bounded Normal Tree (BN-Tree), a novel culling data structure for hierarchical self-collision detection. In situations with sparse self-contact, normal-based culling can be performed with a small output-sensitive cost, regardless of the number of triangles in the surface.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Composite finite elements (CFEs) based on a hexahedral discretization of the simulation domain have recently shown their effectiveness in physically based simulation of deformable bodies with changing topology. In this paper we present an efficient collision detection method for CFE simulation of cuts. Our method exploits the specific characteristics of CFEs, i.e., the fact that the number of simulation degrees of freedom is significantly reduced. We show that this feature not only leads to a faster deformation simulation, but also enables a faster collision detection. To address the non-conforming properties of geometric composition and hexahedral discretization, we propose a topology-aware interpolation approach for the computation of penetration depth. We show that this approach leads to accurate collision detection on complex boundaries. Our results demonstrate that by using our method cutting on high-resolution deformable bodies including collision detection and response can be performed at interactive rates.
    The Visual Computer 06/2013; 29(6-8). · 0.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We introduce an inclusion-field technique for fast detection of collisions between a highly deformable object and another object with limited deformations. We mainly target the cloth simulation application where cloth (highly deformable) collides with deforming skin of a moving human model (has limited deformation as skin stretches and compacts within finite spacial and temporal limits specified by the bending angle and speed). Our technique intermixes concepts from space voxelization and distance fields to make use of the limited deformation nature of human skin. The technique works by discretizing the space containing the object into cells, and giving each cell an inclusion property. This property specifies whether this cell lies inside, outside, or on the surface of the deforming object. As the object deforms, the cells’ inclusion properties are updated to maintain the correctness of the collision detection process. We tested our technique on a generally deforming Bezier surface, and on cloth simulation to detect collisions between cloth and several articulated and deforming human body parts. Results showed that the inclusion field allows real-time collision detection between cloth and limited deformable objects on a standard PC. The technique is simple and easy to implement.
    Journal of Advanced Research. 01/2012; 3(3):245-252.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a novel fast Continuous Collision Detection (CCD) method using SIMD capacity of CPU and idea of dimension reduction. We apply a parallel linear filter culling performed in one-dimensional subspace followed by a parallel planar filter culling performed in two-dimensional subspace before each elementary test, which simultaneously and conservatively tests the relative motion of each primitive pairs in various selected subspace. CPU's SIMD capacity is utilized for parallelizing the projection and filtering process in each subspace. Parallel filter culling in subspace removes a large amount of redundant elementary tests with low cost, and improves the overall performance of collision query. We demonstrate the advantages of our approach when comparing with previous alternatives in various dynamic scenes as benchmarks. In experiments, we observe up to 99% removal of false positives, and a huge magnitude of speed improvement on elementary tests (over 3x). Since our method only correlates the elementary test, it is scalable and can be easily integrated with various available single or multicore CPU based CCD algorithm. In addition, the performance of our method is less sensitive to varying step time.
    Symposium on Interactive 3D Graphics and Games, I3D '11, San Francisco, CA, USA, February 18-20, 2011; 01/2011

Full-text (2 Sources)

Available from
May 28, 2014