Bug Alert: The Knot isn't always drawn correctly! A knotty problem that I have been unable to resolve in a reasonable time ... more in the Notes and Credits. Press <M> to switch to manual rotation using the keys below: <Right Arrow> & <Left Arrow> keys to rotate about the Y axis. <Up Arrow> & <Down Arrow> keys to rotate about the X axis. <a> and <z> keys to rotate about the Z axis. Try key combinations to rotate about several axes simultaneously. Press <M> again to return to automatic rotation.
3D Tutorial Studio: https://scratch.mit.edu/studios/5040029/ My Polyhedrons Studio: https://scratch.mit.edu/studios/5085215/ Lag: I added "wait 0 seconds" at the end of the "Input Keys ..." block to slow the speed down on my PC. You can remove this block if the project lags for you. Huge thanks to @TheLogFather for his "Faster Triangle Filler" https://scratch.mit.edu/projects/24828481/ 3D Rotation theory from Wikipedia: https://en.wikipedia.org/wiki/Rotation_matrix That Knotty Problem or Rendering Bug ---------------------------------------------------- ? Does the error occur because I divide the light coloured faces into 3 rectangles and then one of these rectangles (not the whole face!) seems to be in front of a whole face. ? Or am I completely on the wrong track. NB. If anyone tries debugging and remixing this project I recommend making a drawing with pen and paper showing the distances of the vertices from the origin. Label the distances +/-1, +/-2 and +/-3. They are multiplied by "size" inside the project. You can then see how the rectangular faces of the knot are defined.