So this is one of those areas where we keep things a little vague so the expectations we place on our students aren't excessive, while also leaving the door open for the student to venture into that territory of their own volition.

Basically, every single drawing we do throughout this course is technically an exercise - including the constructional drawings, which are less about drawing a particular thing, and more about the 3D spatial puzzle we're forced to solve in the process. When it comes to the warmups, we definitely want students doing regular rotations of the exercises they encountered throughout Lessons 1 and 2, the challenges, as well as the exercises we encounter here for the leaves and branches.

In terms of the actual constructional drawing exercises that involve actually constructing something based on one or more reference images, we certainly are open to students including that kind of thing into their regular workflow, but because the warmups are generally framed as two or three exercises chosen at random to do for 10-15 minutes, there's definitely a time aspect to it. It is of course fine for students to allocate additional time if the particular task demands it, but we also encourage students to look at spreading an exercise across multiple sittings, or in the case of the rotated boxes, doing just one quadrant instead of all four.

Warmups serve two purposes - they're to help us loosen up and get in the right frame of mind to embark on the next step in the course itself, and they're there to help us continue refining and developing our skills. The 10-15 minute aspect leans towards the former priority, and makes it more difficult to also include the constructional drawing exercises as part of that.

So instead, I leave it vague. Students certainly can continue exploring the kinds of constructions they've tackled in previous lessons, but doing so as part of the 10-15 minute warmups probably isn't the best spot to do it. Rather, you may want to set aside a session here and there to do a constructional drawing of a random type - but ultimately how you go about it is up to you.