Hello I’ll be handling the critique for your 25 wheel challenge.

-Starting with the structural aspect of your wheels, it seems that you are indeed adding an ellipse through the midsections in order to capture the bump that helps to convey the illusion that it is actually inflated rather than being a straight cylinder.

-When it comes to the rims and spokes, we are getting some mixed results, there are definitely some wheels where you take the time to define the front and side panes in order to look more tridimensional and there are other times when you will rely more on flat shapes and fill the side planes with ink, which is a very common issue, however this technique falls more on the form shading side of things, which as explained in lesson 2 texture section, we will not be using, but I will get ore into this in the next point.

-This challenge serves as a reminder of the concepts we learned previously with the texture exercises, most students will have forgotten most of it at this point, and it seems that you have also fallen to the trap as many people have before you.

Most of your attempts at capturing the texture of the wheels use explicit mark making. The issue with this approach is that there are so many details in the tyres tread that drawing them explicitly results in a lot of visual noise and clutter.

Instead, what we should do is to rely on cast shadows and implicit mark making, in order to achieve a texture that transitions from dense to sparse.

-Taking a look at how you've handled those treads it seems to me that you may be relying a good bit on memory, just taking a look at the main pattern and repeating it throughout the wheel.

-So let’s try to explain the difference between the form shading, the explicit mark making and the cast shadows or implicit mark making, and for that I’ll be relying on this diagram. https://imgur.io/SEwsEfO

and here is the explanation.

In the top, we've got the structural outlines for the given form - of course, since we want to work implicitly, we cannot use outlines. In the second row, we've got two options for conveying that textural form through the use of filled black shapes. On the left, they fill in the side planes, placing those shapes on the surface of the form itself, and actually filling in areas that are already enclosed and defined on the form and leaving its "top" face empty. This would be incorrect, more similar to form shading and not a cast shadow. On the right, we have an actual cast shadow - they look similar, but the key point to pay attention to is shown in the third row - it is the actual silhouette of the form itself which is implied. We've removed all of the internal edges of the form, and so while it looks kind of like the top face, but if you look more closely, it has certain subtle elements that are much more nuanced - instead of just using purely horizontal and vertical edges, we have some diagonals that come from the edges of the textural form that exist in the "depth" dimension of space (so if your horizontals were X and your verticals were Y, those diagonals come from that which exists in the Z dimension).

-And the last case I want to talk about is when you use simple lines, like wheel number 5, when the texture consist of shallower grooves, it is a common mistake to think of the grooves as being the forms themselves, but this is no the case, just like any other holes (like in a sponge texture) are not forms - they're negative space, empty space, and the forms in question are actually the walls surrounding them. This diagram helps to explain the distinction. https://imgur.io/SCnATRK .

My main recommendation for you is to first outline the shadow shape while thinking about the form casting it and how it wraps around the surface it is falling on, once you’ve done that you can fill it with black, this will help you to form a better understanding of how all of this comes together. Here you can see a good example https://imgur.com/oAx2pRD .

Okay so. don’t worry if you feel like you ‘ve messed up because it’s completely expected of students to make this mistakes, but I do expect you to go back and review the lesson 2 texture section.

For now I’ll just go ahead and mark this lesson as complete. Good luck!!