Press green flag, wait* till the image is rendered, then* move your mouse on the stage (wait a bit, till you move it again for the image to render). Its rather slow, you might want to try it on turbowarp: turbowarp.org/1014000233 (Naeem5) made it possible to import your own normal map and texture now.
https://commons.wikimedia.org/w/index.php?curid=43694757
