Summary: | 碩士 === 中原大學 === 資訊工程研究所 === 84 === In computer graphics , cloth model is a very complex and an
interesting problem. There are many scholars and experts
devoting the construction , behavior and shading operations for
the cloth model. In general , the cloth model is classified
into geometrical-based and physical-based models. In the
geometry , the construction , simulation , and display of
cloths are based on the surface representation. In the physical-
based model , researches are based on the energy and the force
for the cloth. In this thesis ,we focus on physical-based
particle model. Based on the physics , the internal and the
external force models for the cloth are built. The cloth is
subdivided into equal-sized grids. The microscopic particle is
the primitive element in our model. The dynamic situation of
the cloth is simulated by the behavior of each particle. The
computation cost of simulation is increased exponentially due
to the interrelations between particles. To reduce the
computation cost, the expansion of the interrelated actions is
analyzed hierarchically. Some slight interrelated actions are
ignored and the computation cost are changed from exponential
into linear time. In the reality, the collision detection is an
important factor for the cloth model. We propose a new method
for the collision detection to improve the performance of the
cloth model. An object in the three-dimensional space is
projected into 3 perpendicularly planar tables. If two objects
are intersected, then their projections are in the same entry
of each planar table. Therefore the collision detection of two
objects should be eliminated if the entries of their
projections are different at least one planar table. By the
way, the number of collision detections is reduced dramatically.
|