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

Starting with your organic forms there is a tendency for some (but not all) of your forms to swell continuously through their midsection and/or have slightly pointy ends, so they’re more of a croissant shape than a sausage. You’re not far enough off for this to be a big concern, just actively try to stick to the characteristics of simple sausages that are introduced here when practising this exercise in your warmups. By sticking to those simple properties these forms become very useful building blocks for insect and animal constructions.

You’re doing a good job of drawing these forms with smooth confident lines, and I’m happy to see that this confidence carries over nicely to your contour curves as well. You’ve done well at fitting your contour curves snugly against the sides of your forms, and I can see you’re actively shifting their degree in a deliberate manner, which is an aspect of this exercise that often gets overlooked.

I noticed you’ve drawn all your forms with both ends facing the viewer. While this isn’t actually a mistake, I’d suggest experimenting with using your contour curves to express forms with one or neither end facing the viewer as well, as shown this diagram of the different ways in which our contour lines can change the way in which the sausage is perceived.

Moving on to your insect constructions honestly you’re doing a good job with these. Your linework continues to be smooth and purposeful, and you follow the construction process to a T. I can see you’re using the methodology shown in the demos, starting with simple solid forms and gradually building things up piece by piece, often creating specific relationships between these pieces, showing that you understand how the parts fit together in 3D space.

For the most part these constructions feel really solid and convincing, and I have some advice to share with you that I hope will help you to maintain that 3D illusion as you move forwards. 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.

Fortunately you don’t cut back inside forms you have already drawn very much at all. I’ve marked one example with red on your Hercules beetle and for the most part this came down to there being a gap between lines passing around your ellipse (which is totally normal) and choosing an inner line to represent the edge of the ball form you were constructing, leaving some stray lines outside the construction to undermine its solidity somewhat. Generally it is best to treat the outermost perimeter of the ellipse as the edge of the ball’s silhouette, so everything else remains contained within it. This diagram shows which lines to use on a loose ellipse.

While cutting back into a silhouette is the easiest way to depict the issues with modifying a form after it's been drawn, there are other ways in which we can fall into this trap. On your cricket I marked in blue some places where it looks like you'd extended off existing forms using partial, flat shapes, not quite providing enough information for us to understand how they actually connect to the existing structure in 3D space. While this approach worked for adding edge detail to leaves in the previous lesson, this is because leaves are paper-thin structures, so essentially they are already flat and altering their silhouette won’t flatten them further. When we want to build on forms that aren’t already flat we need to use another strategy.

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.

On this image I’ve shown how we could use this strategy to build up the extra bulk on your cricket’s leg. You’re already building up your constructions with complete additional forms in a lot of places, such as the upper horn on your beetle. With the lower horn, I’ve shown how to create a clearer relationship between the horn and the underlying ball form by using a contour line where the two pieces are fused together. This line also completes the horn form, so that it has its own, fully enclosed silhouette.

You can see this additive 3D construction 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 last thing I wanted to talk about is leg construction. It is great that you’ve stuck with the sausage method throughout the set. You’re doing well at keeping those sausage forms simple, and usually remember to apply a contour line to each joint to show how the forms intersect, nicely done.

I’m happy to see that you’ve taken a swing at building onto your sausage armatures on many of your pages, adding the sorts of lumps, bumps and complexity that you observe in these structures, arriving at a more characteristic representation of the leg in question than what can be achieved with the sausages alone. I have some diagrams to share with you that I hope will help you to build onto your leg structures “in 3D” more consistently as you move forwards.

• These diagrams show how we can add to the construction with complete 3D forms instead of flat shapes and one-off lines.

• This diagram shows how instead of fully engulfing an existing form within a new one, we can establish a clearer relationship between the existing form and the new addition by breaking it into two pieces.

• This ant leg demo shows how we can take the sausage method and push it further, adding all kinds of lumps bumps and spikes to the sausage armature.

• I’d also like to share this dog leg demo with you, which shows how the sausage method can be applied to animal legs. This is important, as we’d like you to continue to stick with the sausage method of leg construction when tackling your animals in the next lesson.

All right, I think that should cover it. Your constructions are coming along well and I’ll go ahead and mark this lesson as complete. Please keep up the good work.