Hello Kairos, I'll be the teaching assistant handling your lesson 4 critique.

Starting with your organic forms with contour curves, there is something to call out, it seems you did one page of contour ellipses, though the assignment was for both pages to be contour curves. Not a huge problem, but it does suggest that you may want to be more attentive when reading through the instructions.

You're doing a good job with keeping your linework smooth and confident, and the majority of your forms are sticking to the characteristics of simple sausages that are introduced here.

I'm happy to see that you're experimenting with shifting the degree of your contour curves/ellipses, as this is one aspect of the exercise that students often overlook.

Looking at the page with contour curves, it appears that the decision whether to include a small contour ellipse on the end of a form was an arbitrary one. Remember that these ellipses are no different from the contour curves, in that they're all just contour lines running along the surface of the form. It's just that when the tip faces the viewer, we can see all the way around the surface, resulting in a full ellipse rather than just a partial curve. But where the end is pointing away from us, there would be no ellipse at all. Take a look at this breakdown of the different ways in which our contour lines can change the way in which the sausage is perceived - note how the contour curves and the ellipses are always consistent, giving the same impression of which ends are facing towards the viewer and which are facing away.

Moving on to your insect constructions, before I get to the meat of this critique, I did notice that according to the dates, a few of these pages were completed prior to your lesson 3 work being marked as complete. One of the requirements for students to submit for official critique outlined in this section of lesson 0 is that students should only move onto the next step when their previous work has been marked as complete by a teaching assistant or instructor. This allows students to apply the advice fom their critique to their work in the next lesson. Can't really do that if you had already completed the homework. This also allows TAs to work as efficiently as possible, by not needing to call out and explain issues multiple times.

Now, fortunately your contructions here are well done, so you won't need to redo any of this work. However the advice I'm going to give you here should be applied to your animal constructions as you move forward.

What I'm seeing in these pages is a pretty strong understanding of how the forms you draw exist in 3D space and connect together with tight specific relationships. I'm seeing evidence of you making use of techniques covered in the earlier lessons, such as the ghosting method, and it generally looks like you're making every effort to stick to the principles of markmaking introduced in lesson 1. On some of your pages your additional lineweight is heavy handed and distracting, being added in arbitrary places. I'm going to assume these pages were done prior to your lesson 3 feedback, and that you started to correct the issue on the later pages.

The next point I want to talk about relates to differentiating between the actions we can take when interacting with a construction, which fall into two groups:

• Actions in 2D space, where we're just putting lines down on a page, without necessarily considering the specific nature of the relationships between the forms they're meant to represent and the forms that already exist in the scene.

• Actions in 3D space, where we're actually thinking about how each form we draw exists in 3D space, and how it relates to the existing 3D structures already present. We draw them in a manner that actually respects the 3D nature of what's already there, and even reinforces it.

Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose, but many of those marks would contradict the illusion you're trying to create and remind the viewer that they're just looking at a series of lines on a flat piece of paper. In order to avoid this and stick only to the marks that reinforce the illusion we're creating, we can force ourselves to adhere to certain rules as we build up our constructions. Rules that respect the solidity of our construction.

For example - once you've put a form down on the page, do not attempt to alter its silhouette. Its silhouette is just a shape on the page which represents the form we're drawing, but its connection to that form is entirely based on its current shape. If you change that shape, you won't alter the form it represents - you'll just break the connection, leaving yourself with a flat shape. We can see this most easily in this example of what happens when we cut back into the silhouette of a form.

For example, I've marked on your beetle in red where it looks like you cut back inside the silhouette of forms you had already drawn. One thing I did notice is that where you cut back inside the ball of the head came down to the fact that your ellipse came out a little loose (which is totally normal), and then you picked one of the inner edges to serve as the silhouette of the ball form you were constructing. This unfortunately left some stray marks outside of its silhouette, which does create some visual issues. Generally it is best to treat the outermost perimeter of the ellipse as the edge of the silhouette, so everything else remains contained within it. This diagram shows which lines to use on a loose ellipse.

On the same image I marked in blue an example where you'd extended off existing forms using partial, flat shape, not quite providing enough information for us to understand how it actually connects to the existing structure in 3D space.

Instead, when we want to build on our construction or alter something we add new 3D forms to the existing structure. Forms with their own complete silhouettes - and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

This is all part of understanding that everything we draw is 3D, and therefore needs to be treated as such in order for both you and the viewer to believe in that lie.

Now, as I noted on the above beetle image in green, this is something you're already applying quite well in some places. We'd like you to strive to always use complete 3D forms wherever you want to build onto organic constructions in this course. You can see this in practice in this beetle horn demo, as well as in this ant head demo. You can also see some good examples of this in the lobster and shrimp demos on the informal demos page. As Uncomfortable has been pushing this concept more recently, it hasn't been fully integrated into the lesson material yet (it will be when the overhaul reaches Lesson 4). Until then, those submitting for official critiques basically get a preview of what is to come.

The next thing I wanted to talk about is leg construction. I'm happy to see that you've by and large made an effort to stick to the sausage method of leg construction on most of your pages, although it looks like sometimes you're missing the contour curves at the joints which show how these forms intersect.

It's not uncommon for students to be aware of the sausage method, but to decide that the legs they're looking at don't actually seem to look like a chain of sausages, so they use some other strategy.

The key to keep in mind here is that the sausage method is not about capturing the legs precisely as they are - it is about laying in a base structure or armature that captures both the solidity and the gestural flow of a limb in equal measure, where the majority of other techniques lean too far to one side, either looking solid and stiff or gestural but flat. Once in place, we can then build on top of this base structure with more additional forms.

I can see you've had a crack at building onto some of your sausage armatures to create a more characteristic construction of the legs of these insects. I've got some diagrams and demos to share with you which I think will help you to build onto your leg constructions more effectively in the next lesson.

• Here see how we can break a larger engulfing form into separate pieces so that each one's silhouette will make ample contact with the existing structure.

• These diagrams show examples of building onto existing structures with 3D forms instead of flat shapes or one-off lines.

• This ant leg demo shows how this approach can be pushed further to capture all sorts of lumps, bumps and complexity that we might see in these kinds of structures.

• Finally this dog leg demo shows an example of how this approach can be applied to animal constructions. This is pertinent, as we'd like students to stick to the sausage method of leg construction throughout lesson 5 too.

All right, I think that should cover it. Your spatial reasoning skills are coming along well, and I think you're ready to face the challenges of the next lesson, so I'll go ahead and mark this one as complete.