github(第一次用 
) GitHub - hakic/GAME201_HW1
把大部分 README.md复制过来
Implemented explicit and implicit euler of mass spring .
Explicit euler, implemented
- Forward euler
- RK2
- RK3
- RK4
Implicit euler, implemented
- Backward euler with jacobi iteration (#iteration=20)
More details:
- Code was based on mass_spring_explicit.py example.
- Moved “Collide with ground” to after “Compute new position” because my explicit code updates x and v at the same time (I didn’t know whether this was acceptable or not)
- Didn’t know how to compute gradient in implicit euler. Used auto-grad in taichi to compute the gradient.
- Settings:
- #particles = 10
- damping = 20.0
- dt = 1e-3
Comparsion
表格复制有格式问题，请前往github查看
Observation
- When damping exists, energy stableness of implicit euler is better; otherwise, all methods are great.
- When damping exists, all simulation looks similar; otherwise, all looks different (please check the following GIFs)
- RK3 / RK4 / implicit euler provide good max spring stiffness.
- Implicit euler provides much better max dt.