Jumping right in with the structural aspect of the challenge, I'm very pleased to see that you've made effective use of your ellipse guides (and especially with the fact that you made case by case decisions on whether to jump to the next degree over or stick to the same degree as the previous ellipse, where the jump would have been excessive for the given distance). I imagine it was a bit more challenging to work in the smaller sizes, but I guarantee that it was well worth it, and that freehanding your ellipses would have gotten a fair bit more in your way.

I'm also glad to see that you varied how much wider through the midsection different wheels/tires got, which helps to convey how much more some wheels would land with a thunk when dropped, while others would do so with more of a bounce due to the greater impression of them being inflated.

When it comes to the spokes/rims of your wheels, I did catch a couple of issues you'll want to be aware of.

  • As shown here, it's important to be mindful of where the different edges you're drawing actually exist in 3D space. When we slip back into thinking about what we're drawing only in the two dimensions of the page, we become prone to these kinds of mistakes, which can undermine the illusion of solidity we're trying to create.

  • As shown here it seems you may have gotten confused as to which angle the wheel was being seen from, and therefore which of the structures' side planes would be visible.

Continuing onto the textural aspect of the challenge, this is an area where it's super common for students to reveal that they may have allowed the textural concepts and exercises from Lesson 2 to slip through the cracks. Sometimes this will result in the student remembering the general idea of how we tackle texture, causing them to try and consider how to use filled areas of solid black (but without necessarily reviewing exactly how those filled black shapes are specifically used in this course), while other times students forget about those concepts completely and just focus more on drawing what they see in whatever way feels natural.

As such, we find it to be useful to use this challenge as something of a trap - not something we assign revisions over, but as an opportunity to show students that given how long and arduous this course is, it's remarkably easy to just forget things, and going back and reviewing material is something you may well need to do.

When it comes to texture specifically - at least, how we handle it in this course, which is very specific to this course - we are ultimately looking at the same kind of problem that the course as a whole explores: spatial reasoning. We imply the marks we draw (you can refer to the implicit vs explicit markmaking section for more specific information on this) by drawing the shadows our textural forms cast on their surroundings, not by drawing the forms themselves (in terms of outlining them, or otherwise drawing anything about the form itself). It's the shape of the shadow itself, which is designed based on our understanding of the relationship in 3D space between the form casting it and the surface receiving it. And so, as stressed in these reminders, in this course we're never just drawing what we see. We're looking at our references, and understanding what they tell us about the forms in question, and then deciding on how to convey the relationships between them in space.

The reason we use implicit markmaking instead of explicit is fairly simple, although it's not always obvious. For example, looking at any of your wheels, for example the top left of this page (numbering would have been nice to be able to point out specific cases more easily, but oh well), it looks excellent floating in the void, all full of detail. But when it becomes part of an existing drawing, all of that packed detail can actually work against you by drawing the viewer's eye to it whether you want it to or not. This interferes with our ability to control composition (which is all about dictating how the viewer experiences a piece, what they look at and in which order), which while outside of the scope of this course, is still something I want to give students the tools to engage with more easily.

Explicit markmaking basically locks us into an agreement with the viewer: whatever is drawn is present, and whatever has not been drawn, is not present. And therefore to convey each textural form, we have to declare its presence explicitly. Implicit markmaking on the other hand gives us more freedom by disconnecting the marks we draw from the specifics of what is present.

We are able to achieve this because of the fact that we're drawing cast shadows, rather than outlines. As shown in this diagram, depending on how far the form is from the light source, the angle of the light rays will hit the object at shallower angles the farther away they are, resulting in the shadow itself being projected farther. This doesn't strictly require us to necessarily always think about where our light source falls (which can be important in other situations, but I mention this to avoid adding even more considerations to what we're doing here). It's just the fact that the same form could be conveyed with virtually no cast shadow at all, or a distinct cast shadow if a reasonable size that allows it to be fully perceived, or a huge cast shadow that blends into other shadows beside it, that gives us the freedom to not have to draw all of our detail completely and lock ourselves into a very dense level of detail. It also allows us to transition from one to the next (something explored in the texture analysis exercise from Lesson 2), so as to give ourselves full control over how what we're drawing is captured on the page.

This does also mean that ideally we want to make it clear that when we use a filled area of solid black, that it always represent a cast shadow. In this sense, a filled area of solid black is a visual cue for the viewer to interpret, and we don't want them to have to expend additional brain power to distinguish between "is this a cast shadow, or is it form shading where the artist just filled in the side plane, or is it some other sort of void being filled in (for example, like how the middle-top on this page has its center hole filled in completely)". The fewer steps they have to go through to understand the drawing, the more clearly we're able to communicate with them - and so, we ideally want filled areas of solid black to always correspond with cast shadows.

The last thing on this topic I wanted to explain is that when it comes to those tires with shallow grooves, or really any texture consisting of holes, cracks, etc. it's very common for us to view these named things (the grooves, the cracks, etc.) as being the textural forms in question - but of course they're not forms at all. They're empty, negative space, and it's the structures that surround these empty spaces that are the actual forms for us to consider when designing the shadows they'll cast. This is demonstrated in this diagram. This doesn't always actually result in a different result at the end of the day, but as these are all exercises, how we think about them and how we come to that result is just as important - if not moreso.

Anyway! As promised, though you stepped into that trap, it was entirely intentional and expected, so there won't be any revisions assigned on this basis. Just be sure to review the material from Lesson 2's texture section so as to refresh your memory of what's explained there, and also take some time to consider whether there may be other sections of the course that similarly slipped through the cracks.