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

Starting with your organic forms it looks like you're trying to stick to the characteristics of simple sausages that are introduced here, and some of your forms are pretty close. I'm seeing a bit of a tendency for one end of your forms to get a little stretched out and become "pointy" or sometimes be a bit lopsided. Focus on keeping both ends rounded, like balls.

I noticed a few places where you'd redrawn parts of your contour curves, presumably to make corrections. 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.

There's also some signs of hesitation on a few of these contour curves, so as introduced here, remember to always prioritise a smooth confident stroke first and foremost. We achieve this by making use of the ghosting method, and using our whole arm to draw. This point also applies to your insect constructions, where I'm seeing a mixture of some smooth confident line work, and some areas that show some stiffness and hesitation.

I can see you've made a real effort to experiment with shifting the degree of your contour curves, good work! 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.

Moving on to your insect constructions your work is kind of mixed. There are elements of what you're doing here that are very good - such as how you usually attempt to work from simple to complex, and generally avoid jumping too far ahead in the complexity of any one thing. The way in which you approach aspects of construction however does have a tendency to lean more towards actions taken in 2D space - where we're just putting marks down on a page, and taking all the liberties that allows us - rather than taking actions in 3D space, where we're forced to always think about how the things we're introducing exist in 3D space, and how they're attaching to structures that are similarly also 3D.

Let's look at the whole 2D vs 3D action thing first, as I'm sure you're kind of confused as to what I mean. 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 haven't cut back inside the silhouette of forms you have already drawn very often. I found this example on the leg of your jewel bug, which I've highlighted in red. Here it looks like you'd established a sausage form for the lower leg, then when you came back with a pass of detail to refine the construction, you'd ended up cutting inside that sausage, undermining its solidity. Something that happens more frequently is a tendency to extend 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. I've marked some examples of these extensions in blue on your dragonfly.

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.

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.

Before I move on, I'll talk through one more example of how we can build up our constructions with solid forms. If we take a look at this section of your treehopper, I've highlighted in blue where you'd got some flat partial shapes connecting a series of solid ball forms together. Here I've put together a diagram to show how we can build a similar arrangement from solid forms. If we assume that the protrusion is symmetrical, then the centre of the purple additional form will attach to the centre line on the body. I've used an ellipse as an approximation of the "footprint" where the purple form connects to the red form in 3D space. Then in green I've extended sausage-like forms off the purple one. The lines get a little cluttered where they attach but basically what I've done is similar to how the legs are attached to the body of your louse using ellipses. Finally the ball-like forms have been attached to the ends of the sausage structures, in blue. When faced with complex structures such as this, always start with big simple forms, and work your way towards smaller elements, adding complexity in successive passes.

This only pops up on a couple of pages, but I'll go ahead an mention it anyway. There are some pages like this beetle where your construction was quite small, and a lot of the space on the page was unused. Drawing small can make it more difficult to think through the spatial reasoning puzzles involved with these constructions, as well as trickier to engage our whole arm and draw from the shoulder. The best approach to use here is to ensure that the first drawing on a given page is given as much room as it requires. Only when that drawing is done should we assess whether there is enough room for another. If there is, we should certainly add it, and reassess once again. If there isn't, it's perfectly okay to have just one drawing on a given page as long as it is making full use of the space available to it. In the case of your beetle, this would likely have benefited from turning your paper 90 degrees (to landscape format) and drawing the construction larger.

The next thing I wanted to talk about is leg construction. You're showing some familiarity with the sausage method as introduced here, though you don't always follow the method to the letter.

• You'll sometimes only draw parts of your forms where they overlap, so they become flat partial shapes. Much like how you "drew through" overlapping leaves and petals in the previous lesson, we'd like students to drawn through their forms here too, to gain a stronger understanding of how these pieces exist in their entirety, and connect together in 3D space.

• Some constructions such as this mantis some of the leg forms are straying pretty far from the characteristics of simple sausages (as introduced in the organic forms exercise).

• There appear to be some constructions that are missing the contour lines at the joints which we use to communicate how these sausage forms intersect and connect together in 3D space.

• Rather than using a centre line to plan your leg sausages, I find it helps to keep the construction clearer to use a dot (usually at the joint) instead.

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.

Now the last thing I want to discuss is in regards to your approach to the detail phase, once the construction is handled. In some places you appear to be getting caught up in decorating your drawings (making them more visually interesting and pleasing by whatever means at your disposal - usually pulling information from direct observation and drawing it as you see it), which is not what the texture section of Lesson 2 really describes. Decoration itself is not a clear goal - there's no specific point at which we've added "enough".

What we're doing in this course can be broken into two distinct sections - construction and texture - and they both focus on the same concept. With construction we're communicating to the viewer what they need to know to understand how they might manipulate this object with their hands, were it in front of them. With texture, we're communicating to the viewer what they need to know to understand what it'd feel like to run their fingers over the object's various surfaces. Both of these focus on communicating three dimensional information. Both sections have specific jobs to accomplish, and none of it has to do with making the drawing look nice.

Instead of focusing on decoration, what we draw here comes down to what is actually physically present in our construction, just on a smaller scale. As discussed back in Lesson 2's texture section, we focus on each individual textural form, focusing on them one at a time and using the information present in the reference image to help identify and understand how every such textural form sits in 3D space, and how it relates within that space to its neighbours. Once we understand how the textural form sits in the world, we then design the appropriate shadow shape that it would cast on its surroundings. The shadow shape is important, because it's that specific shape which helps define the relationship between the form casting it, and the surface receiving it.

As a result of this approach, you'll find yourself thinking less about excuses to add more ink, and instead you'll be working in the opposite - trying to get the information across while putting as little ink down as is strictly needed, and using those implicit markmaking techniques from Lesson 2 to help you with that. In particular, these notes are a good section to review.

I've marked some specific examples of texture that has room for improvement on your jewel bug.

• Sometimes you'll add substantial patches of black to places that seem arbitrary. Remember we're using areas of filled black for cast shadows only. For the sake of these constructions you can ignore colour patterns and imagine your subject has been painted solid white or grey. Sometimes it can be difficult to distinguish between form shadows and cast shadows. Here is a diagram showing the difference. You can also find an explanation on cast shadows in this video.

• Sometimes your application of texture looks explicit as you tend to focus on outlining your details. I've included some examples of drawing implicitly in the notes on your work, but I'll also share this diagram which illustrates the difference at a larger scale.

Okay, I think that covers it. On the whole, you're not far off, but I am concerned enough about what I feel is a tendency to prioritise detail and decoration over the solidity of the 3D construction that I will be assigning some revisions. This feedback is quite dense, so in brief this is what we're aiming for:

• Always respecting the fact that what you're building up is real, solid, and 3D. The page is just a window looking out onto your creation.

• Smooth confident linework. (You do this correctly a lot of the time, this is encouragement to be more consistent.)

• Correct application of the sausage method of leg construction.

• If you choose to add texture (it is optional in this lesson) do your best to follow the guidance for texture set out in lesson 2.

I suggest you take a good bit of time to go through everything I've shared with you here - all of the points I've raised, and all of the diagrams I've provided. It is likely to take multiple read throughs at different times to really absorb it all, so don't expect to jump right into your revisions right away. That said, once you've had plenty of time to absorb my feedback, you'll find your revisions assigned below.