[SOLVED] CS Simulating Cloth

Simulating Cloth
By Andy Pierce and Jernej Barbic
1

Cloth simulation overview
Problem of interest
Applications
Challenges Forces

Deformation
Large Steps in
Cloth Simulation
[Baraff and Witkin 1998]
2

Forces and stiffness matrices
Cloth Forces Stretch
Shear Bend
Bend Formula
Force Derivatives
[Baraff and Witkin 1998]

N1 N2
3

Timestepping the forces
Explicit
Fast
Unstablewithlargetimesteps
Implicit
[Baraff and Witkin 1998]
Mustsolvesparselinearsystem Cantakelargetimesteps
4

Challenges
Complexity of Formulas 3rd order tensors
Large matrices
Collapsing Triangles Length of normal -> 0 Explosions
5

Results
6

Model
Triangles
FPS
% Forces + Stiffness Matrix
% Solver
Curtain
2400
25
67
33
7

Model
Triangles
FPS
% Forces + Stiffness Matrix
% Solver
Curtain
2400
25
67
33
8

Model
Triangles
FPS
% Forces + Stiffness Matrix
% Solver
Skirt
4608
12
75
25
9

Multithreading
Force and Stiffness Matrix Computation
50
45
40
35
30
25
20
15
10
5
0
12345678
Number of Threads
10
Milliseconds

Other considerations
Damping Forces
Collision Detection
[Bridson et al. 2002]
Code Optimizations
[Govindaraju et al. 2005]
11