just follow the line! click and drag to draw (or use the spacebar). carefully trace the line to draw an impossible 3D cube. press 'a' when you're done to hide the guide. then doodle all you want
Thanks to @scratchisthebest (scratch is agreeably the best!) I did this by experimenting with the original project, and then changing the guide. :) (Note: You might notice that the "cube" is sort of still a triangle, but it appears like a box. That is most likely (tell me if i'm wrong) because a triangle is 2D and a cube is 3D, hence why I named it "Impossible '3D' Cube Tutorial".)
