Jumping right in with your form intersections, the way this exercise works - much to the frustration of my students - is that we introduce the exercise back in Lesson 2, well before students are really expected to have any kind of comfort in its execution. We introduce it so that when you move onto the constructional drawing exercises we perform from lessons 3-7, your brain already has some form of context or direction for what it's learning from all of the 3D spatial puzzles it is forced to solve. Then we assign the exercise again here in Lesson 6 - again not with the expectation that you're going to nail it all, but expecting more comfort with intersections involving flat surfaces, though less comfort with those involving curving surfaces - and in Lesson 7, to make sure that you're still moving in the right direction, and that you've developed more comfort with those curving surfaces as well.

To put it plainly, you're definitely ahead of the curve on that - you're showing a great deal of comfort with with intersections involving flat surfaces and curved surfaces, and while there are little mistakes, they're not mistakes that suggest a lack of understanding, but rather just the usual bumps that get ironed out with practice. The grasp of the concepts is all there.

The main point I wanted to offer for you to work on going forward has to do with the way in which we judge both the orientation and the eccentricity of the intersections (eccentricity in terms of how dramatic or shallow a curve ends up being). You're doing a good job in most cases of judging when to use a curve and when to use a straight line, as well as which direction that curve should go, but the angle and how extreme that curve should be is off at times.

I noted some mistakes (as well as one intersection that has confused a lot of people that you nailed quite well) here on your first page. In regards to what I'm showing for the sphere/box intersection towards the upper left, we can look at the planes of the box each as knife-blades that are cutting into the sphere. The orientation of each such "blade" dictates which cross-sectional slice of the sphere is relevant to us for that part of the intersection - and so ensuring that we're thinking about the blade will help us pick the correct angle. This diagram also illustrates this point, while also illustrating how to think about rounded surfaces (which would be less relevant to you).

Continuing onto your object constructions, it wouldn't be an overstatement to say that I'm impressed. Quality of the results isn't important to me (although the quality of yours certainly isn't in question), but what is really being showcased here is that you have bought into the core principles this lesson espouses whole heartedly. This lesson is, at its core, about precision.

Precision is often conflated with accuracy, but they're actually two different things (at least insofar as I use the terms here). Where accuracy speaks to how close you were to executing the mark you intended to, precision actually has nothing to do with putting the mark down on the page. It's about the steps you take beforehand to declare those intentions.

So for example, if we look at the ghosting method, when going through the planning phase of a straight line, we can place a start/end point down. This increases the precision of our drawing, by declaring what we intend to do. From there the mark may miss those points, or it may nail them, it may overshoot, or whatever else - but prior to any of that, we have declared our intent, explaining our thought process, and in so doing, ensuring that we ourselves are acting on that clearly defined intent, rather than just putting marks down and then figuring things out as we go.

In our constructions here, we build up precision primarily through the use of the subdivisions. These allow us to meaningfully study the proportions of our intended object in two dimensions with an orthographic study, then apply those same proportions to the object in three dimensions.

Needless to say, you made excellent use of orthographic studies in your drawings, and you've demonstrated an inordinate degree of patience and care with each construction. You identified each and every relevant landmark, you made clear and concise choices about how you were interpreting and understanding your reference objects/images, and you applied them decisively when building each construction back up in 3D space.

The only construction where I felt things probably went a little awry was this mug (the base was probably drawn too small, and a little too narrow, causing the structure as a whole to both taper too much and to change its proportions). But that isn't anything to be ashamed of - given the tools we have at our disposal in this course, proportion is one of those where we trickle out tools and information, so as not to overwhelm the student, and there is still a bit more to be learned on that front in Lesson 7 (where we actually explore how to build up 3D unit grids, allowing us to fully control the size/proportional specifications of what we're constructing). What matters here however is that while things went a bit off, you stuck with the construction and saw it through, abiding by all of the previous decisions and following them to the letter. As such, what you ultimately constructed still appeared solid and three dimensional, and instead of appearing like mistakes made by the student, it appears more as though you faithfully captured an object that was just a little oddly made.

Anyway! All in all, fantastic work. I'll go ahead and mark this lesson as complete. Keep it up.