SpriteKit physics in Swift - Ball slides against wall instead of reflecting

Question

I have been creating my own very simple test game based on Breakout while learning SpriteKit (using iOS Games by Tutorials by Ray Wenderlich et al.) to see if I can apply co

Answer 1

I was seeing exactly the same issue, but the fix for me was not related to the collision detection issues mentioned in the other answers. Turns out I was setting the ball into motion by using an SKAction that repeats forever. I eventually discovered that this conflicts with SpriteKit's physics simulation leading to the node/ball travelling along the wall instead of bouncing off it.

I'm assuming that the repeating SKAction continues to be applied and overrides/conflicts with the physics simulation's auto-adjustment of the the ball's physicsBody.velocity property.

The fix for this was to set the ball into motion by setting the velocity on its physicsBody property. Once I'd done this the ball began bouncing correctly. I'm guessing that manipulating its position via physicsBody by using forces and impulses will also work given that they are a part of the physics simulation.

It took me an embarrassing amount of time to realise this issue, so I'm posting this here in case I can save anyone else some time. Thank you to 0x141e! Your comment put me (and my ball) on the right path.