This is an example of how you COULD potentially track a Sprite outside of the Stage. Feel free to play around with it. Click on stage to set position and direction. Click on rocket to launch from new placement. Adjust sliders to make stage larger or smaller, or change ship speed. Added cursor keys for turning and speed. Added rainbow pen trail, turn off with spacebar. Added stage modes... -1 = bounce mode (changes direction) 0 = hit mode (forced to stay at stage boundary) 1 = warp mode (moves to other side of stage)
Created in response to this forum message... "Option to allow sprites to move off the screen" [ https://scratch.mit.edu/discuss/topic/4762 ] See inside for comments.