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objective-cswiftsprite-kitskphysicsbodyskphysicsworld

Getting direction of object moved by the physics engine

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)

Solution

  • 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.