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

Starting with your organic forms these are looking considerably more smooth and confident than your lesson 2 pages for this exercise. There's an occasional wobble here and there, but I do want to congratulate you on the improvement and encourage you to keep it up.

It is clear that you're working towards the characteristics of simple sausages that are introduced here. There are a few subtle deformities to some of the forms, such as ends getting slightly flattened or pointy, or some slight bulging through the midsection, but you're on the right track, good job.

There are a couple of spots where you've drawn a contour ellipse on an end of a form where the contour curves tell us the tip faces away from the viewer. I've crossed them out and added two that were missing here. Remember that these ellipses are no different from the contour curves, in that they're all just contour lines running along the surface of the form. It's just that when the tip faces the viewer, we can see all the way around the surface, resulting in a full ellipse rather than just a partial curve. But where the end is pointing away from us, there would be no ellipse at all. Take a look at this breakdown of the different ways in which our contour lines can change the way in which the sausage is perceived - note how the contour curves and the ellipses are always consistent, giving the same impression of which ends are facing towards the viewer and which are facing away.

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 image from the previous paragraph showing the different ways in which our contour lines can change the way in which the sausage is perceived.

Remember to draw around the small ellipses on the end(s) of the forms 2 full times before lifting your pen off the page. This will help to execute them smoothly and is something we ask you to do for every ellipse that you freehand in this course, as explained here in lesson 1.

Moving on to your insect constructions these are coming along nicely, you're doing a good job of starting your constructions with simple solid forms, and gradually building them into something more complex, piece by piece. I like that you're (usually) drawing through your forms, as this will help you to develop your understanding of 3D space, so please keep that up.

I do have some points that should help you get more out of these constructional exercises in the future.

The first of these relates to differentiating between the actions we can take when interacting with a construction, which fall into two groups:

• 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.

• 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. We draw them in a manner that actually respects the 3D nature of what's already there, and even reinforces it.

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.

For example, I've marked on your weevil in red where it looks like you cut back inside the silhouette of forms you had already drawn. One thing I did notice is that some of the instances of cutting into forms (though not all) came down to the fact that your ellipses would come out a little loose (which is totally normal), and then you'd pick one of the inner edges to serve as the silhouette of the ball form you were constructing. This unfortunately would leave some stray marks outside of its silhouette, 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.

On the same image I marked in blue some places where 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.

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.

Here I've made a couple of edits to the weevil construction. If you look at the snout, rather than stopping the line where it meets the edge of the ball form for the head, I've run the line across the surface of the ball, establishing how the snout connects to the ball in 3D and giving the new addition a its own complete silhouette. I've drawn the armoured shell on top of the abdomen larger, so that it wraps around the ball forms you had already drawn, rather than cutting back inside them.

Once again I need to remind you to draw around your ellipses two full times before lifting your pen of the page. You're doing this correctly often enough that I think you understand that it is a requirement, but there are some cases like this spider where the large ellipses aren't drawn around twice (and are getting stiff as a result) which suggests you may want to be more conscious of the individual actions you're taking when working through these exercises.

The next thing I wanted to talk about is leg construction. It is good that you made the effort to attempt to use the sausage method for some of your constructions. 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.

So, while I do see that you're trying to use the sausage method, it looks like you've quite frequently struggled to stick with simple sausage forms as introduced with the organic forms exercise. There are various things like pointy ends, swelling midsections, random bulges etc. This is most likely due to one or more of the following:

• Attempting to draw the entire leg with the sausage forms, instead of treating them as a starting point on which we will build all these bumps and bulges later.

• Getting overwhelmed with the number of forms it is necessary to draw in order to construct a full set of insect legs, and devoting less time to each individual form than is necessary to draw them to the best of your current ability. Remember to take your time and use the ghosting method to full effect for every line or form you draw in these exercises. You can also place a dot on the page for where you want the end of your form to go, so you have something to aim for when ghosting them. You are welcome, and encouraged, to split a construction over multiple sittings/days if necessary.

• Mechanical difficulties drawing organic forms when they get small or skinny. They can be quite tricky! This may seem counter-intuitive, but make sure you keep using your whole arm to draw these, even when they get small, as this will help you to keep your marks smooth. You may also find it helpful to include practising smaller/skinnier sausage forms for a few minutes as part of your warm ups.

When using the sausage method remember to include a contour curve at each joint, to show how these sausage forms intersect in space. I've highlighted them in red on this copy of the sausage method diagram. These little curves might seem trivial, but they are a very useful tool, they help to reinforce the 3D illusion of these structures very effectively, and It saves us from having to add other stand-alone contour lines along the length of individual forms.

The last thing I wanted to talk abut relates to your comment about this mantidfly that it is "too complex." While I do understand the frustration here, it is worth pointing out that you do get to choose what kinds of insects you'd like to draw. I think it's great that you chose a more challenging subject here, and that the complexity is quite reasonable. (Sometimes I see students constructing centipedes and I don't envy them, sooo many legs.)

If when you observe your reference, you find you aren't able to identify the subject's basic construction (as discussed in this section) then I'd recommend finding another reference that you can more easily understand. This doesn't necessarily mean you have to pick a simpler subject, sometimes seeing the same species from a different pose or angle can make it easier to figure out what forms you're looking at. For example this mantidfly would probably be easier to understand if its raptorial forelegs were reaching forward, instead of all bunched up underneath its head.

There is plenty going right in your mantidfly construction, you've identified the major forms of the head thorax, and abdomen, and connected them together with some smaller forms, building things up piece by piece. I've done a quick construction of this insect here and the first step is remarkably similar to your own.

The next image I meant to separate into more stages for you but accidentally worked the green and blue on the same layer. Green is establishing the base for where the wings, legs and arms will connect, as well as dropping in the eyes. Blue is some central flow lines for the wings, and sausage forms for the legs. It looks like a lot, but if you're patient and methodical, working one form at a time and carefully observing the reference to make sure the form is derived from the information present in the reference (rather than what we remember) then it is well within your capabilities.

The next image shows in pink adding contour lines for the intersections at the joints on the legs, connecting the sides of the wings, and constructing the antennae and the front of the face from simple forms. We could take this further, adding the segmentation to the abdomen, constructing the armour plating on top of the thorax, and building all the bumps and claws on the legs, but I've kept this simple so it will hopefully feel approachable. On the last image I've used black to add extra line weight to help clarify some of the overlaps. I hope that this makes this construction feel a bit less daunting.

Conclusion I've called out a few areas where there is room for growth, but you're heading in the right direction and all the points I've talked about here can continue to be addressed into the next lesson, so I'll go ahead and mark this one as complete. Please be sure to actively tackle these points as you handle your animals. It's not uncommon for students to acknowledge these points here, but forget about them once they move on, resulting in me having to repeat it in the next critique (which we certainly want to avoid). If anything said to you here is unclear or confusing you are allowed to ask questions.