A drawing is a Projection of a 3D scene on a surface.

There are two variables that we can play with:

1. The surface
   • a plane
   • a sphere
   • a cube
   • any other surface
2. The type of projection
   • along parallel lines -> Axonometric projection
   • along radial lines -> Central projection

And combining these results in some familiar things:

• Axonometric Projection + Plane => Used in architecture drawings or in CAD.
• Central Projection + Plane => 1, 2, 3 point perspective (linear perspective)
• Central Projection + Sphere => 4, 5 point perspective (curvilinear perspective)

Why? Because that's what vision is. A Central Projection (light rays going in) on the inside of a Sphere (the eye).

• Central Projection + Cube => Video Game Skybox