Summary

• 1. Detect collision \(\|p_1-p_2\|\leq r_1+r_2\)

• 2-a. If collision (relative speed \(>\epsilon\) )
• • Elastic collision (/bouncing) \(v_{1/2}= \alpha\, v_{1/2} \pm \beta\,J/m_{1/2}\)

• 2-b. If static contact (relative speed \(\leq\epsilon\))
• • Friction \(v_{1/2} = \mu\;v_{1/2}\,\), \(\;\;\mu\in[0,1]\)
  • Avoids jittering

• 3. Correct position (project on contact surface)
• • \(p=p \pm d/2\,u\)
  • \(d=r_1+r_2-\|p_1-p_2\|\): Collision depth