/ic/ - Artwork/Critique

>>4067473
I'm drawing the 250 boxes exercise.
I got few problems:
Is it something I'm supposed to complete before moving onto the next chapters? At the rate I'm drawing it'll take at least a bit longer than a week and the major problem is that - I don't really "feel" perspective this way and all I did observe is that the "back" (red) should result from the green lines being correct and that's all. Should I read something meanwhile before drawing 200 more boxes? Drawing over wavy line was much better - I really felt 3D even if technically I have numerous problems for anything that isn't roughly isometric towards the viewer.