In the 3D images below you can familiarise yourself with the 3D interface.
| Action | Mouse | Touch |
| Rotate: | Hold down button one and move. | One finger touch and move. |
| Zoom in/out: | Shift and hold down button one and move vertically. | Double finger touch and change distance. |
| Zoom (alt): | Roll mouse wheel. | |
| Undo All: | Press 5 (compare with F5). | Simultaneous triple touch. |
| Toggle Support for concave faces: | Press 'c' (convex / concave). |
Note that button presses are valid for all canvases on one page.
A cube only has convex faces:
The small stellated dodecahedron has concave faces. Initially
they are drawn here as if all faces are convex. This is more
efficient, but leads to a wrong model:
This can be fixed by pressing 'c'.