Starting with your form intersections, there one significant point I noticed was that you appear to be drawing your cylinders without any foreshortening at all - which as noted here in the 250 cylinder challenge would be entirely incorrect. The vanishing point would only be at "infinity" (in the manner discussed in Lesson 1, which you can refresh your memory on here, we just released updated videos this past weekend) if the orientation of the cylinder were perpendicular to the viewer's angle of sight.

Now, I'm guessing that the reason you drew it this way was because you had an ellipse guide with limited ellipses available - although given that this exercise is one we have freehanded in the past, most students do end up freehanding this one as well. Either way, if you run into a situation where your limited ellipses leave you with the option of drawing something that's fundamentally incorrect, or freehanding the mark, then freehanding the mark is best. Cases where the cylinders are very short (like in the upcoming wheel challenge) would generally be okay, given that their limited length would also result in very little foreshortening, but when you've got longer forms the absence of foreshortening becomes very noticeable.

I noted this issue here on your work, and also noted that for the sphere-box intersection below, you appear to be treating that rear edge as though it is in the front, resulting in an inverted intersection.

Additionally, I noticed a number of other smaller issues with the intersections, which I've noted on this page. One point to keep in mind with these intersections is that each intersection line can be broken down into separate parts, each individual segment being the result of an intersection between a particular pair of surfaces. Pay attention to which surfaces each segment involves, and consider whether they're flat, whether they're curved, and in which direction they're curving. I've noted on the page along with my corrections, little arrows that denote how a given surface is flowing through space.

While this is something of a simplification, you can keep the following in mind as a starting point:

• Intersections between two flat surfaces result in a straight line

• Intersections between a flat surface and a curved surface results in a curve. That curve may be more rounded or more shallow, depending on the angle at which the flat surface is shearing through the curved one.

• Intersections between two curved surfaces result in a complex curve - like an S curve with separate parts - where it transitions from wrapping more dominantly around one surface, then the second, then back to the first.

Lastly, this diagram may help illustrate the consideration of individual surfaces I've explained above.

Continuing onto your object constructions, you have definitely demonstrated a great deal of progress over the course of this set. I can certainly see you attempting to apply the core principles of the lesson even towards the beginning - that is, the concepts of precision and the specificity with which we flesh out all of our constructions here - but the execution was definitely uncertain. To briefly expand on what I mean by "precision" - it's 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.

One of the biggest issues you exhibited at that point was less about the lesson itself, but more about how you were opting to execute your linework in cases like this. I can see that you used your ruler when laying down the bounding box and subdivisions, but that when you drew the final objects, it seemed you fell back to freehanding everything. While that in itself isn't a problem - most of the ellipses would probably not suit your ellipse guide, so it's normal to freehand them, but any straight lines (like the length of the mug) should still employ a ruler, and anything else should be employing the techniques we introduced in Lesson 1 - including drawing through ellipses, and using the ghosting method. With the mug, you appear to have fallen back to chicken scratching and hesitating when executing your marks, which is pretty significantly against the core principles of this course.

Fortunately, it was something you did end up addressing yourself as you moved through the lesson work. In particular, your last few constructions really leveraged a lot more in regards to subdivision, and while I only saw your orthographic plans for the computer mouse demo, this construction definitely suggests that you were applying the concepts from this section - although if you weren't doing so entirely, I would strongly recommend reviewing those notes. And of course, when this kind of thing comes up again in Lesson 7, be sure to include your orthographic plans in your submission.

In regards to that last construction, I have two points to suggest:

• Firstly, for the buttons, you laid out little boxes for each circular button and identified the center point upon which each button would sit, but the buttons themselves are still floating inside of their enclosing box. Instead, if you want the button to be smaller than the box you've got, you can draw another plane inside of it, from diagonal to diagonal (whilst aligning to the appropriate vanishing point so it converges consistently with the outer edges of the enclosing box), then draw your button's ellipse such that it fits snugly within it, as shown here.

• Secondly, don't employ line weight as heavily as you have here - it'll flatten out your construction. In general, line weight should be used as explained here, to clarify how different forms overlap one another. I understand that the construction has a ton of additional linework, and you want to make the object stand out from it, but you needn't worry - I'm very used to discerning objects out of such forests of linework, so it's best that you continue to apply the concepts covered throughout the course.

I'll go ahead and mark this lesson as complete.