Circle Deflection: Calc Outbound Angle After Collision

[cam875]

how do u calculate what one circle does when it collides with another circle at a specific point on a specific heading? I need to know how to figure out the outbound angle that the circle will travel on after colliding.

 

[Espen]

Isn't this just the reflection law, $$\theta_{inbound}=\theta_{outbound}$$ with theta measured on the tangent (plane) of the collision surface at the collision point?

 

[cam875]

im not sure that's why I am asking.