This space curve in a cube with projections (1b) is a math classic. Use a torch to compare the projections of the space curve (in the center) on a plane with the 3d-printed ones.
This space curve in a cube is a math classic. To view its projections on a plane, just take a torch (or your cell phone lamp).
This visualizes a 1-parameter family of cubic functions or a 3d graph of a function in one variable in a 3d-coordinate system.