The role of cloth in computer graphics has increased in the
last decade, especially with character animation for films
and games. Many methods have been used to simulate cloth
and clothing, often focusing on the visual appearance and
the physical properties. A high degree of fidelity has already
been achieved for off-line applications, however, simulating
realistic cloth remains an expensive endeavour, even when
considering recent advances in computer hardware. One can
sacrifice detail to achieve an interactive cloth simulation with
a coarse mesh relatively easily, but to simulate detailed cloth
interactively or even just to accelerate off-line computations
additional techniques must be researched.
Simulating cloth in real-time is a challenging endeavour due to the number of triangles necessary to depict the
potentially frequent changes in curvature, in combination with the physics calculations which model the deformations.
To alleviate the costs, adaptive methods are often employed to refine the mesh in areas of high curvature,
however, they do not often consider a decimation or coarsening of areas which were refined previously. In addition
to this, the triangulation and consistency checks required to maintain a continuous mesh can be prohibitively time
consuming when attempting to simulate larger pieces of cloth. In this work we consider an efficient edge-based
approach to adaptively refine and coarsen a dynamic mesh, with the aim to exploit the varied nature of cloth
by trading the level of detail in flat parts for increased detail in the curved regions of the cloth. An edge-based
approach enables fast incremental refinement and coarsening, whereby only two triangles need updating on each
split or join of an edge. The criteria for refinement includes curvature, edge length and edge collisions. Figure 1 illustrates a piece of cloth falling over 3 tiered spheres.
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Figure 1: Cloth falling on 3 tiered spheres. |
SYS Consulting Ltd.
