Jumping right in with your arrows, you're off to an excellent start. Not only are you doing a great job of keeping the physical widths of your arrows consistent (that is, in 3D space, with consideration to perspective), you're also keeping in mind how the same perspective compression applies to the negative space, the gaps between the zigzagging sections, to really effectively convey the depth in the scene.

That awareness of how what you're drawing sits in a three dimensional space carries over nicely into both your organic forms with contour ellipses and contour curves - you're adhering very nicely to the characteristics of simple sausages, and your contour lines are smoothly executed while factoring in the behaviour of that shifting degree to demonstrate how the various cross-sections move around in space. I did notice a minor hiccup on this sausage here where the degree of your contour ellipses should have been getting wider as they move farther back from the viewer (since the relatively simple sausage itself doesn't appear to have been doing any dramatic turning to warrant straying too far from the basic principle of the degree shift). The slight widening for the contour ellipse just before the smaller tip to the right side does make sense however - just before that we hit the narrowest contour ellipse, at which point the sausage starts turning away from the viewer again, as shown here. I did push the tip ellipse over a little to account for the structure turning away from the viewer, however.

Continuing onto the texture section, one thing to keep in mind is that the concepts we introduce relating to texture rely on skills our students generally don't have right now - because they're the skills this entire course is designed to develop. That is, spatial reasoning. Understanding how the textural forms sit on a given surface, and how they relate to the surfaces around them (which is necessary to design the shadow they would cast) is a matter of understanding 3D spatial relationships. The reason we introduce it here is to provide context and direction for what we'll explore later - similarly to the rotated boxes/organic perspective boxes in Lesson 1 introducing a problem we engage with more thoroughly in the box challenge. Ultimately my concern right now is just how closely you're adhering to the underlying steps and procedure we prescribe (especially those in these reminders).

As a whole however, your work is showing a great deal of care and patience, and I'm very pleased to see how much you're leaning into the idea of working with filled areas of solid black, and being intentional in how you design those shapes. As you continue to push through the course, there are a few things I want you to keep in mind however:

• When dealing with textures that are made up of cracks, grooves, holes, etc. - basically anything where the thing you refer to by a noun refers not to a physical structure but rather an empty "negative" space, you're going to feel tempted to simply draw that thing and fill it in with black. Your tree bark texture is a good example of this happening. Keep in mind that the things you're actually drawing, the filled black shapes you're designing, are always cast shadows. So you have to think about what physical structure is casting it, and which surfaces are receiving it. This diagram should help somewhat, but ultimately I just want you to keep this concept in mind as you continue forwards, as it's not something I remotely expect students to be comfortable with right now.

• For the scales texture, you seem to have forgotten that the goal is to work towards a bar of solid white on the far right. In addition to this, it seems you might be thinking more about thickening the lines of the individual scales, rather than thinking as much about your marks representing actual cast shadows. This results in you being locked into some degree of outline for each scale, rather than being able to transition smoothly from white to black. These notes should be helpful to this effect, especially the bit about "lost and found edges" on the diagram.

Your dissections demonstrate a similarly developing grasp of this concept, but keep pushing yourself to think of every mark you draw in terms of texture as being a cast shadow. That said, your work is coming along great here - I don't usually provide direct feedback on this section because it's not really worth the trouble, given the purpose it is meant to serve. So, don't take my critique as a sign that you've done anything wrong, but rather that you're so much on the right track with this that you earned a little extra.

Continuing onto your form intersections, in a lot of ways these share a similar goal to the texture section - they serve as a representation of spatial reasoning at its most concentrated, and so it's entirely normal for students to be completely bewildered by the intersections themselves. Our interest in this is really only in introducing the problem, and in ensuring that students are able to apply the ghosting method patiently and mindfully with increasingly complex tasks. Not only have you done that remarkably well, but your form intersections themselves are far ahead of our expectations at this point, both in terms the arguably simpler intersections between flat surfaces, and those involving more complex curving surfaces.

This exercise will come up again in Lesson 6 and Lesson 7, as we want to see how the work develops after lesson 3-5's focus on constructional drawing exercises (which is where this course specifically targets and develops spatial reasoning skills - everything prior to this point has been getting students equipped to tackle them effectively). But in truth, your work would be very well done even for a submission included in Lesson 6.

Lastly, your organic intersections are coming along very nicely too, although there's one thing I want you to keep in mind going forward. When tackling this exercise, I want you to avoid making modifications to the silhouettes of your sausages after the fact, like cutting into those silhouettes as we can see in this portion, where you introduce a new edge along with the cast shadow to demonstrate how one sausage curves around the other. This is something you should be capturing in how you design the sausage form's silhouette initially. It's also the reason why we always build these piles from the bottom up - once drawn, the lower sausages won't be able to "respond" to the inclusion of another sausage beneath them, since they've already been drawn - and so, with each new sausage added, we consider how it would rest at the top of the stack, and ensure that the silhouette is drawn in a way that captures this properly.

So! All in all, fantastic work. I'll go ahead and mark this lesson as complete.