Elastic 666 test

Test scenario

• Perfectly elastic collision (restitutional coefficient = 1)
• Zero friction
• 6 x 6 x 6 number of 10 kg spheres
• Small perturbation in position to collapse
• Metric: system energy

Tested solver list

• Rai
  • Bisection solver (Rai solver)
• Bullet
  • Sequence impulse
• ODE
  • Dantzig
  • LCP PGS
• MuJoCo^[1]
  • PGS
  • CG
  • Newton
• Dart
  • Dantzig
  • LCP PGS^[2]

Commentary

• [1] Elastic collision cannot be simulated in MuJoCo. See Bouncing test page for more details.
• [2] Dart LCP PGS fails with timestep > 0.01: the simulation is blown up. We only report the results with timestep < 0.01 for LCP PGS.

Results

With the same test setup with 666 test, but for elastic collision, we investigated the energy of the system. The result is as follows:

The RaiSim has good energy preservability and also fast contact simulation for the elastic collision of primitive shape objects.