Performing your own physics calculations for a collision in Sprite Kit

Question

I'm trying to set up some elastic collisions using Sprite Kit. There is an issue with the case of multiple objects resting near each other as I asked in Sprite Kit Physics Collision Issue I am confused on the timing of the situation for a collision. I've tried to set `dynamic` to `NO` in `-didBeginContact:` delegate method, calculate final speeds, then in `-didEndContact:` set `dynamic` to `YES` and then set the velocities correctly. The reason I want it to be dynamic outside of the collision is because I want friction/gravity etc to be available. What is wrong with the order/logic? I looked at `-didSimulatePhysics` method, but it didn't seem like the way to go.

Accepted Answer

I'm trying to set up some elastic collisions using Sprite Kit

I think you're misunderstanding the physics in play here. An elastic collision is an oversimplification of a collision. In reality, no collision results in a perfect transfer of energy. I've explained the physics here in an answer to the related question you linked to.

I suspect reading through that you will see that an "elastic" collision can be done in SpriteKit, but most people don't realize you need space between the objects. You shouldn't need to do your own physics calculations.

Performing your own physics calculations for a collision in Sprite Kit

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