Starting with your organic forms with contour lines, these are mostly coming along pretty well, with a couple things to keep an eye on:

• Firstly, always keep striving for the characteristics of simple sauages. You're not far off, but you sometimes have pinching through the midsection, or ends that get a little more stretched out.

• Remember that as we slide along the length of a given sausage form, the degree of our contour curves is meant to change. There are a few factors that impact how they change (whether they get wider or narrower), with one of those simply being the twisting/turning of the form, but as a baseline if we have a completely straight cylindrical form, the contour curves will get wider as they move away from the viewer. This is demonstrated in the lesson 1 ellipses video. In yours, I think you're mostly keeping them fairly consistent, and in one case you've got them shifting in the wrong direction.

Continuing onto your insect constructions, as a whole I'm very pleased with your work here. While there are a few things I'm going to call attention to, as a whole I feel you're generally working very much in the right direction in terms of building up your structures through the combination of smaller, simpler components, working from simple to complex and striving to create something solid and three dimensional throughout the whole process.

There are a lot of little things that stand out to me in this regard - for example, the antennae on this ant have clear consideration for how their segmentation is wrapping around the underlying structure, reinforcing the illusion that the underlying structure itself is three dimensional, and therefore carrying that solidity through into the result.

There are however some areas in which you break away from that sort of thing, and so just as this kind of choice reinforces the illusion we're trying to create, there are choices that will undermine it as well.

Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose - it just so happens that the majority of those marks will 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.

If you take a look at this weevil drawing, I've marked out two different colours. In red, I've pointed out where you cut into the silhouette of a form, as shown in the diagram in the previous paragraph. This isn't something you do often, and even here, it was obviously just because of the looseness of that initial ellipse. Not a big deal - just remember that the outer perimeter of the ellipse is what defines the form's silhouette.

In blue, however, is an issue that comes up more often in your work. Here you've added partial, two dimensional shapes, extending off the flat silhouette of another form. This falls into the same category - altering the silhouette - and similarly to cutting into a silhouette, it can undermine the illusion we're trying to create.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure, 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.

You can see this in practice in this beetle horn demo, as well as in this ant head demo. This is all part of accepting that everything we draw is 3D, and therefore needs to be treated as such in order for the viewer to believe in that lie.

Now, as a whole I can see plenty of examples of you building up your constructions correctly - it's just that you need to be aware of the mindset that distinguishes these two approaches. Looking at how you build upon your sausage structures for the legs, for example, you rely quite a bit on altering the silhouettes. An alternative approach would be as shown here to add individual masses, defining how they wrap around the existing structure and ensuring lots of contact between the new mass's silhouette and the existing structure's surface. You can also see this demonstrated here, and in action in this ant leg and in this dog leg (as this will continue to be relevant throughout the next lesson.

I also noticed a tendency to overuse contour lines specifically when you were altering the silhouettes of your structures. That shows me that you were aware of the flattening effect the approach had - but unfortunately, contour lines will merely accentuate the volume and illusion of form that is already there. Piling them onto something that has already been flattened isn't generally going to work too well.

Anyway, as a whole I still feel you're doing a good job and are moving in the right direction. I'll go ahead and mark this lesson as complete, and leave you to apply what I've shared here on the next one.