Analyze the cube under the sun and calculate its shade and shadow, then render it with Pencil, Ink, Markers and Pastel according to the value associates with numbers recommended.
Id still be interested to know why there is gradual value change. I'ts so counterintuitive to me 2:33 for example 2-> 1 , is that because of reflected light from the ground? I would have liked to see many sun angles while illustrating this system.
