4 different projections to render a 3D cube on a 2D plane (in gray)

- orthographic: projection through lines orthogonal to the plane
- perspective: projection through rays from the line to the plane
- glasses: same as perspective, for both left & right eyes; the two projections can be seen with glasses (e.g. anaglyph glasses with red/cyan filters)
- oblique: projection through lines a bit slanted from the orthogonal direction; make the cube parallel to the plane to see the effect (click "Steady" button)