action Thirdp(){
	var camdist = 200; //camera distance
	camera.tilt = -45;
	while(1){
		camera.pan = my.pan;
		camera.x = my.x-camdist*cosv(camera.pan); 
		camera.y = my.y-camdist*sinv(camera.pan); 
		my.pan -= 10*time_step*mouse_force.x;
		camera.z = my.z+camdist;
		wait(1);
	}
}