PC Controls: W and s keys to go forward and backward. A and d keys to move side to side. Left and right arrow keys to point side to side . Up and down arrow keys to point up and down . Mobile Controls: Joystick up and down to go forward and backward. Joystick left and right to go left and right. Left and right arrow buttons to point side to side. Up and down arrow buttons to point up and down.
This was just a little idea that popped into my head about how to fill a triangle. The depth sorting took ages to figure out and has a lot of bugs but it is at least functional. The 3d engine came from a YouTube tutorial by The Green Flash.