I've got good news and I've got bad news.

The good news is that your work throughout this lesson is phenomenal. The bad news is that I'm honestly hard pressed to actually find anything to actually suggest or offer as a means of applying these exercises more effectively, or squeezing more out of them. As it stands, you're leveraging just about each exercise as well as I can imagine they could be, and if there's room for further improvement, it is beyond me to identify what those improvements would be.

I should clarify - I'm talking about these drawings as exercises, rather than as actual artworks, as that is the purpose behind each and every one. My responsibility here is to ensure that students have effectively learned how to go about developing their spatial reasoning skills, so that when they continue on their own, they will continue to be able to hone those skills, while also making use of what they have already developed to help them digest and absorb other courses, lessons, tutorials, etc. Needless to say, your spatial reasoning skills have developed exceptionally well, and that is demonstrated most of all with the first exercise of this submission.

Your form intersections are, except for one or two spots, superb. I can see a clear grasp of how each intersection is the sum of many parts - each part being the interaction between specific surfaces, yielding a particular section to the overall intersection line, and then being stitched together either with sharp corners situated right at the edge transition from one flat surface to another, or with smoother, more gradual transitions as we shift from one curving surface to another.

As for the few issues I did find:

• With this cone-sphere intersection, you may not have given this one enough thought, asa it ended up coming out rather oversimplified. Instead, where we've got the curve-on-curve intersection of the sphere and the cone's length, we'd end up with a more complex transition from following one curve to the other, resulting in an S curve. Then we'd hit the edge between the cone's two surfaces, shifting onto the simple flat base, which would cause us to follow a different curve of the sphere, resulting in a sharper corner between them. I see clear signs that you already understand this, but to drive home the point about the different slices of a sphere that we can potentially follow, take a look at this diagram.

• With this pyramid-cylinder intersection. I definitely think you already understand the issue here based on other cases where you've handled this far better, but similarly to the previous point, each of the pyramid's faces would be intersecting with a different aspect of the cylinder, due to each face being oriented differently. The one I marked as "more curved" is aligned such that it leans more into the cylinder's curvature, whereas the one below it would be aligned more to the length of the cylinder, which is actually more flat. That is to say, the length of a cylinder is curved in one dimension, and straight/flat in the other.

Continuing onto your cylinders in boxes, you're handling these well - that is to say, applying the line extensions correctly and giving yourself all the information you would need to continue growing. I am however seeing certain tendencies that you should already have noticed yourself (I'm reiterating them here to pad out my critique :P):

• Your cylinders' side edges tend to converge to a farther vanishing point than the box's own edges. This basically means that they're not converging enough, which in turn is impacted by the relationship between the ellipses on either end.

• You also have a tendency, when the cylinders get longer, to have the lines converge in pairs. We can see this quite a bit on number 4, where we've got two groupings of blue lines, and two groupings of green lines.

With those out of the way, all that's left is for me to gush over all the things you did well with your vehicles:

• You've taken immense care to be as precise as you reasonably could, pushing those subdivisions so much farther than any human would consider reasonable, and really fleshing out each vehicle construction to a considerable degree throughout the lesson's work.

• You've done an excellent job of working from simple to complex, focusing on the vehicles first as a collection of primitives (while this is not strictly visible in the drawings themselves, it's very clear that you were thinking in this manner, breaking the objects down and building them back up, as doing so is really what gives them all such a considerable sense of solidity.

• It's genuinely impressive how you've managed to keep track of just so many independent subdivision lines. I had considered calling out the fact that you didn't really build up your curves using a series of straight lines (as discussed here in Lesson 6) but ultimately I thought it wouldn't be fair to do so, given just how many subdivisions you ended up using. The only place where I really felt you might have benefited from putting down more straight lines/flat planes prior to smoothing and rounding out your corners would have been in the rolls-royce, which had more organic curves to it. I would have tackled it as shown here. Conversely, while the BMW 600 also included plenty of curves and such, their nature resulted in the way in which you drew them holding up quite well, primarily since they're really just a bunch of already boxy forms with corners that are merely rounded out (in the vehicle proper, I mean). That is, as opposed to more flowing organic curves.

I can of course continue with more glowing praise, but I think you understand by now just how well you've done. And so, I'll go ahead and mark this lesson - and the course as a whole - as complete. Congratulations! I wish you the best in whatever it is you intend to move onto, and I expect with the patience, discipline and focus you've demonstrated here, you'll be able to ultimately achieve whatever it is you'll be working towards.