Answers for "(2D) How to maintain perfect elastic collisions?"
http://answers.unity.com/questions/707483/2d-how-to-maintain-perfect-elastic-collisions.html
The latest answers for the question "(2D) How to maintain perfect elastic collisions?"Answer by Kiwasi
http://answers.unity.com/answers/863727/view.html
Record the total initial momentum of the system. In each collision check the the total amount of momentum, and adjust as appropriate.
Unity will remain pretty good elasticity, but due to floating point precision errors and rounding errors the system will eventually break down.Sun, 28 Dec 2014 08:16:11 GMTKiwasiAnswer by tanz94
http://answers.unity.com/answers/863686/view.html
One can record the velocity before collision that can be done through raycasting(OnCollisonEnter would be of no help sine it records zero velocity).Also you have compute the normal and tangent and take dot product with initial velocity to get the velocity after collision.Follow these vidoes (https://www.youtube.com/channel/UCa0KlT6mWPvUdk-48kFaSUg/videos ) for better understanding.Soon a blog will be written on it.Sun, 28 Dec 2014 06:20:25 GMTtanz94