2:43 PM, Monday May 24th 2021
Congratulations on finishing the 250 Box Challenge. This is especially a hard one, so I can understand how you feel.
Let's start with your lines. I see many wobbly lines and some fixed lines that are drawn a couple of times. It is good that you planned out your lines before drawing them. What I am curious about is that whether you are doing enough ghosting before drawing the actual line. Once you planned out the line with dots, ghost the line as many times as you need so that your muscle will remember the movement, and that way, you will draw more confident and straight lines. Thinking about the line while you draw hinders the drawing process, resulting in a wobbly, non-confident line so try to focus only on the movement of your arm since your arm would remember the movement.
I see you extended the corners of the boxes in the right direction, which is good, but there are some problems in your perspective. In the three-point perspective, there are three sets of vanishing points. Every parallel line should converge to a specific vanishing point. In each box, there are three sets of lines, each set containing four parallel lines.
Since your foreshortening is too shallow, most of the lines are parallel, or they diverge. The lines should converge, not diverge. You should pay attention to the planning stage of your lines before drawing them. One way to understand this might be to apply a deeper foreshortening. This way, your vanishing points would be closer, and you can see the divergence easier. This diagram explains the behaviors of the lines, so give it a read and try to apply it to your own boxes. Also, this specific order of drawing the lines might help you get more accurate results.
If you still have some problems understanding the three-point perspective, I would recommend you read the lesson material one more time and watch the videos Uncomfortable posted on youtube. You can find the first and the second videos here.
Before starting Lesson 2, doing this challenge a bit more would be better for you to understand the perspective better.
This challenge might be hard, tiresome, and even annoying, so taking your time and do it slowly might help you in this process. That way, you won't burn out. You can build up enough strength and determination to finish this challenge. If you feel like you are falling behind, or if you lose your focus while doing this challenge, taking some time out and finding your reason to draw might be helpful. Don't judge yourself too harshly. You are doing your best to learn something you love, and that's what matters. And if you did everything you can to keep going but still failed to get out of depression, maybe getting professional help would be better. It helped me go through the depression, and it also improved my art, so I definitely would recommend it.
Good luck with your studies :)
Before starting Lesson 2,study the materials I mentioned above and then draw 50 more boxes. Once you are done, you can post your revision here for feedback.