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

Before I comment on your work itself I just want to note that the images you have uploaded are a bit on the small side at 480 by 640 pixels. Still workable, but if you are able to upload larger images (at least 1000 pixels on the short side) when you submit your next homework that will help me to see your individual lines more clearly, as well as providing draw-overs on your work if needed.

Starting with your organic forms you're doing a pretty good job of sticking to the characteristics of simple sausages that are introduced here.

It is good to see that you’re experimenting with varying the degree of your contour curves. Keep in mind that the degree of your contour lines should be shifting wider as we slide along the sausage form, moving farther away from the viewer. This is also influenced by the way in which the sausages themselves turn in space, but farther = wider is a good rule of thumb to follow. If you're unsure as to why that is, review the Lesson 1 ellipses video. You can also see a good example of how to vary your contour curves in this diagram showing the different ways in which our contour lines can change the way in which the sausage is perceived.

There are a couple of spots where it looks like you've gone back over a contour curve, presumably to correct it. In this course it is best to leave mistakes alone rather than attempting to correct them. Correcting a mistake will create the impression in our brain that the mistake was addressed, whereas really addressing the mistake would involve reflecting upon why it may have occurred and adjusting our approach to try and avoid the mistake in the future - something we usually do by giving ourselves more time to think through the actions we take while doing the work. Leaving the mistakes alone allows us to come back after the page is complete to assess where the mistakes occurred, and how we might do better in the future. On the other hand, redoing a line generally just makes the work messier.

Moving on to your insect constructions these are coming together pretty well. It is good to see that you’re starting each construction off with simple solid forms, and generally putting thought into how to fit the various pieces of your constructions together “in 3D” as though you had real, solid building blocks in front of you and were fitting them together like a puzzle.

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.

I see that ThatOneMushroomGuy already introduced you to the above rule, and I can see that you’re generally making an effort to stick to it. I’ll call out a couple of cases where you’re not quite following to the letter, and provide some examples of how to build up constructions in 3D instead.

Fortunately you don’t really cut back inside the silhouette of forms you have already drawn, and the only places where I’m seeing it happen are probably accidental. If we take a look at this spider I’ve marked with red where there was a gap between the passes around your ellipse (which is totally normal) then it looks like you picked one of the inner lines to represent the silhouette of the abdomen, leaving a stray line outside of the construction, 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.

It is also possible to alter the silhouette of an existing form by extending it. On this image I traced over your solid sausage forms with green and then traced over in blue where you'd extended off those sausage 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.

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.

Here is the concept applied to the spider’s leg, using black for the sausage forms, red for the intersections, and green for additional forms. 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. It looks like you tried out a couple of different strategies for constructing legs. I think you had the sausage method in mind for the majority of your pages, but keep in mind that ellipses are not sausage forms and using ellipses to construct legs will make them too stiff. It is a little hard to tell with the low resolution images, but I think you may also be a bit inconsistent about applying a contour curve at each joint to show how the sausage forms intersect.

It's not uncommon for students to be aware of the sausage method as introduced here, 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 as shown in these examples here, here, and in this ant leg demo and also here on this dog leg demo as this method should be used throughout lesson 5 too.

The last topic I want to talk about is texture and detail. Some of your textural work is very much heading in the right direction, and I thought some of the doughnut-shaped textural forms you implied on the abdomen on this spider were very well done. The texture on other pages is a bit mixed, with the texture on the far side legs of this construction appearing more haphazard. If you’re trying to push the far side legs back, applying straight parallel hatching lines will do the trick. Adding this amount of detail to the far side legs actually draws more attention to them, which we probably don’t want to do, and we should be working with individually designed shadow shapes, rather than relying on randomness.

The large areas of solid black on this construction and this beetle don’t really provide information about the surface texture, but actually remove information, by obscuring the underlying construction. As discussed in this video we want to focus on cast shadows when describing texture. A form shadow occurs when the surface of a form faces away from the light source, but for a cast shadow to occur one form must block the light, stopping it from hitting another surface. This diagram shows the difference between a form shadow and a cast shadow using a sausage form as an example, and how we can apply this to texture by drawing the small shadows cast by the textural forms running along the surface of the sausage. This allows us to imply the surface texture without having to explicitly outline every tiny bump.

All right, your constructions are coming along well and I’ll go ahead and mark this lesson as complete. Please refer to this critique as you tackle your animal constructions in the next lesson, so we can build on the points discussed here in your next critique.