Getting direction of object moved by the physics engine

Question

i am using spritekit to learn about physics behaviour in games, when a sprite node ball bounces off a surface, the physics engine will automatically calculate its new direction.

how do i get this new direction in code?

i am using swift, xcode spritekit. but object c spritekit (cocos2d) is fine too

(the aim is to get a fire trail behind the bouncing ball, but i dont know how to rotate the particle emitter based on ball's vector of movement. the emitter is currently added as a child of the ball node)

Answer 1

To get the "direction" you should read the velocity property of the physicsBody of your node.

To rotate your particle emitter, you should modify the zRotation property of the node.

Answer 2

Well, the most best idea for getting a rotation of a node is getting eulerAngles. But since it showed radians, I converted to degrees. This is the code that I got when getting the rotation of a camera Node

print(round(GLKMathRadiansToDegrees(Float(gameController.camera.eulerAngles.z))))

Hope This helps