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

Starting with your organic forms you're doing a good job of sticking to the characteristics of simple sausages that are introduced here. Occasionally one end of a form gets slightly flattened or pointy instead of staying rounded like a half sphere but most of these are really close to what we're aiming for in this exercise.

Your contour curves are coming out well too, and I'm happy to see that you're experimenting with varying their degree. Keep in mind that the degree of your contour lines should generally 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 have done this correctly in the cases where both ends of the form face the viewer, or neither ends face the viewer, but where one end faces the viewer it looks like you may be slightly unsure of how to vary the degree of your curves. You can see a good example of how to apply this in this diagram.

Moving on to your insect constructions you're doing a great job. You're starting your constructions with simple solid forms and gradually building complexity piece by piece without undermining the solidity of the forms you have already established. Your showing a good understanding of how the forms you draw exist in 3D space and connect together with specific relationships. Nicely done.

Normally I need to spend some time explaining the difference between taking 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, and 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.

What stops me in my tracks a little is when a student is already taking the vast majority of their actions in 3D, as you have done here.

I can see that you've gone to considerable effort to avoid cutting back inside the silhouettes of forms you have already drawn, as was requested by ThatOneMushroomGuy in your lesson 3 feedback.

I did spot one small area where I think you accidentally cut back inside one of your forms. If you take a look at this leaf hopper we can see that by choosing the inner line of your (2D) ellipse to represent the silhouette of your (3D) abdomen form, you left a stray line floating outside of your construction, which undermines the 3D illusion a little. There is a way we can work with a loose ellipse and still build a solid construction. What you need to do if there is a gap between passes of your ellipse is to use the outer line as the foundation for your construction. Treat the outermost perimeter as though it is the silhouette's edge - doesn't matter if that particular line tucks back in and another one goes on to define that outermost perimeter - as long as we treat that outer perimeter as the silhouette's edge, all of the loose additional lines remain contained within the silhouette rather than existing as stray lines to undermine the 3D illusion. This diagram shows which lines to use on a loose ellipse.

So, 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.

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.

Now, this is something you're already doing great at. I can see oodles of places where you're building up complexity in your constructions with compete 3D forms and the results are feeling really solid. I did spot a couple of places where you'd added a little bit of extra complexity with a line or partial shape, as noted here on this section of your crab.

I also want you to avoid trying to describe 3D structures with single lines, as seen on the antennae of this dobsonfly. A single line is infinitely thin, and does not provide enough information for the viewer to understand how it exists in 3D space. Instead use one of the 3D forms that you have learned how to construct in this course. You may end up with something that looks a little different from the reference image. We aren't to focus on reproducing the reference image at all costs, but rather to treat is as a source of information that helps us determine the direction of our goal.

The next thing I wanted to talk about is leg construction. I'm happy to see that you're working with the sausage method of leg construction throughout your pages. 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 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.

While your leg constructions are definitely hitting the right notes, I did notice a tendency for you to add extra contour curves on the surface of your sausage forms, which as noted on the sausage method diagram will stiffen them needlessly. Instead, as noted on this section of your leaf hopper we only apply these contour curves at the joints, where they represent the intersection between these two forms in 3D space.

As a more general note, there are places where you seem to be using quite a few additional contour curves on a single form. Contour lines themselves fall into two categories. You've got those that sit along the surface of a single form (this is how they were first introduced in the organic forms with contour lines exercise, because it is the easiest way to do so), and you've got those that define the relationship and intersection between multiple forms - like those from the form intersections exercise. By their very nature, the form intersection type only really allows you to draw one such contour line per intersection, but the first type allows you to draw as many as you want. The question comes down to this: "how many do you really need?"

Unfortunately, that first type of contour line suffers from diminishing returns. The first one you add will probably help a great deal in making that given form feel three dimensional. The second however will help much less - but this still may be enough to be useful. The third, the fourth... their effectiveness and contribution will continue to drop off sharply, and you're very quickly going to end up in a situation where adding another will not help. I find it pretty rare that more than two is really necessary. Anything else just becomes excessive.

Be sure to consider this when you go through the planning phase of the contour lines you wish to add. Ask yourself what they're meant to contribute. Furthermore, ask yourself if you can actually use the second (form intersection) type instead - these are by their very nature vastly more effective, because of how they actually define the relationship between forms. This relationship causes each form to reinforce the other, solidifying the illusion that they exist in three dimensions. They'll often make the first type somewhat obsolete in many cases.

I have one more tip for you before I wrap this critique up. If you're going to add the shape of a cast shadow underneath your constructions, it will help to reinforce your 3D illusion if you consider the shape of this shadow a bit more carefully. Right now, some of them look like they were added as an afterthought, and they're not really adding information to your drawing, but conflicting what is already there. I've done a quick redraw of the cast shadow shape under your dobsonfly as an example. Notice how where the legs touch the ground plane they also touch this shadow shape, this will help make them feel more grounded, instead of looking like the insect is floating. I've also made the shape much more specific- as a general rule of thumb, if the ground plane is flat it may help if you consider the shadow shape to be a projection of the silhouette of your construction.

All right, you're doing a great job so I'll go ahead and mark this lesson as complete.