I'll start out by answering your questions, and if there's anything left to add at the end, I'll do so. While questions can in most submissions be a bit of a pain, they help add structure to critique for challenges like this one where the work is often more open-ended.

When drawing, should I visualize the texture and surface where the shadows will be cast on the paper, and then add the shadows? (I think I’m finally getting this, but I want to confirm).

This question depends on what you mean by 'visualize' - nothing in this course specifically expects students to actually visualize in the sense of seeing things through their mind's eye, for two reasons:

• Firstly, I have aphantasia, so I actually can't do that - my mind's eye is totally blank. You can learn more about this in this video I made for the Proko youtube channel.

• Secondly, the spatial reasoning skills we teach throughout the course develop a different kind of "visualization" - rather than being able to see things, it's more about understanding the spatial relationships between forms on an intuitive level. Kind of like how you can navigate your bedroom in the dark because you're familiar enough with where all of the furniture is, despite not being able to see it.

As explained in these reminders from Lesson 2, the process we employ in studying our textures is one that requires us to understand the nature of the forms we're trying to convey, and how they relate to the areas around them. We pull that understanding by observing our reference and considering what we're looking at, and then it's that understanding which we use to design the shadow shapes we then draw.

So if we interpret your "visualization" as understanding the relationship between those 3D elements spatially, then yeah - first you consider the relationship, then you design the shadow that would be cast based on it (as an outline), and finally you fill it in. If however you're talking about visualizing it in a sense of trying to project the shape you want on the page, and then simply tracing over what you're visualizing, then no, and that's exactly what makes it so difficult. We have to consider the shadow shape this form is going to cast without being able to actually see the form, based purely on an invisible spatial understanding of it. It's very hard to do, and is something that develops with practice, alongside the larger spatial reasoning we develop throughout the course (which is why we recommend spreading the challenge out as you work through the rest of the course).

Can I sketch with a pencil first and then add the cast shadows afterward, or does that contradict my previous question?

No. As I noted in the previous point, what we're asking you to do is hard, so it's natural to want to reach for a tool or a strategy that'll make it easier - but it's hard because what it's designed to train your brain, the way in which it is meant to rewire your brain's behaviour and how it tackles certain kinds of problems, is very different from what you're used to doing. The solution is not always to find a way to make the task easier - sometimes a task is just difficult because the skills it's meant to develop are challenging. Sometimes there's no way around a mountain, you just have to make your way through it.

To be clear, that is within the context of this exercise, just as our general use of ink and rejection of pencil is specific to the context of this course. That's not to say you can't do that when adding texture to your own drawings - what we do here all has very specific purposes, to train and rewire the way in which your brain works, so that when you're drawing your own things, you don't have to worry so much about the "how", and you can focus more of your cognitive resources on the what of what you're drawing.

In the left (darker) part of the third column, I often struggle because I feel the need to include form shadows (instead of cast shadows) to achieve the desired effect. What’s your take on this?

Form shading simply doesn't play a role in what we're doing for this course, and definitely not in what we're doing in this exercise. What I'm going to share is something I also mentioned in the critique you linked to, but it essentially illustrates the mechanics we're leveraging in this exercise, and how it works to achieve the "desired effect" of the gradient from light to black, going from right to left:

As shown in this diagram, depending on how far the form is from the light source, the angle of the light rays will hit the object at shallower angles the farther away they are, resulting in the shadow itself being projected farther.

Given an infinite distance from the light source, the shadow being cast will be infinitely large, based on what's show in that diagram. So, you don't need form shading to obscure the hard edge of that black bar - you just need to be willing to allow your cast shadows to get big enough that they all start merging together in a singular complex shape.

Where the problem arises is when you're not necessarily working with cast shadows. For example, in the wool fabric texture at the top of this page, the areas you filled in started out more as form shading rather than cast shadows, and this led easily into you simply filling in the spaces in between. Cast shadows require us to think about the shadow shape and how we're designing it - it's the shape itself that conveys the relationship between the form casting it and the surface receiving it. If you're not thinking about how to design the shape of each individual form and are instead jumping ahead to the result (without consideration for the process that is meant to lead to that result), then you essentially end up with the same kinds of problems that arise with explicit markmaking. That is, achieving the gradient becomes very difficult, and the "rules" of the exercise fall apart.

We can see similar outcomes on the bottom texture of this page (the crocodile skin), where you appear to have focused on filling in the negative space between the scales, and then made that negative space expand more and more, making the scales themselves shrink. Again - these "shadows" were not designed individually as shapes, you were chasing the end result in the absence of the prescribed process.

The cauliflower texture at the top of this page was much better executed - you still outlined the clusters of cauliflower individually which is not a good idea, but internally you were focusing much more on the 3D structures present, and how those forms relate to one another. So you're definitely making progress in this regard, but you tend to avoid designing those cast shadow shapes more often than you face them head-on.

What’s the correct way to interpret and depict the light: coming from the left or from above?

The nature of the gradient means that the light source is always coming from the far right, and the shadows are cast towards the left. The diagram from the previous section demonstrates why this is the case, and I can see a number of cases where you did more correctly try to work with cast shadow shapes, but where you ran into difficulties because your shadows were being cast in other directions. For example, the top and middle textures on this page, and the texture at the bottom of this page.

There is some perspective in the image I’m drawing. Often, the center of the image is seen from above, with light coming from above as well. On the left and right sides, forms and shadows appear in perspective, but in opposite directions. Should I stick to one approach or combine both and reproduce the perspective effect? It might be easier to settle on one option.

This suggests to me that you might be more focused on drawing the reference image, which isn't really the goal here. As mentioned earlier when I talked about these reminders from Lesson 2, we're looking at the reference image as a source of information, to understand how the different forms that are present relate to one another. We then use that information to create our gradient - but we're not drawing what we see. We're simply understanding what we see, and then using that information for our own purposes. So a reference image may be shown at a different point of view than fully top-down, or laid flat, but your brain is still capable of translating that information such that you can arrange it on a flat surface (and of course with practice through this exercise, your ability to do that will improve - as long as that is what you're attempting to do). To be clear though, as this is important, the big point here is that you're not just drawing the reference image as you see it.

It takes me at least one hour to complete a panel. So more than 5 hours per page is it too long? For the results this does not seem relevant.

It is indeed not relevant. As stressed in Lesson 0, how long it takes you to do an exercise doesn't matter - all that matters is that you're doing your best to follow the instructions as they're prescribed.

I fall in love with this work: https://imgur.com/a/AgsTWid, and especially the hair on the third page. Could you please help me to reach that?

I really can't stress this enough - the results do not matter. Producing something pretty for the purposes of your homework for this course isn't going to change anything. What matters is following the process and adhering to it so it can impact your brain and help change the way your brain understands and processes the kind of information we're working with. It is very easy, and very common, for students to shift their approach because they're excited about the short-term goal of producing something nice and pretty right now - but in so doing, they end up straying from what will allow them to achieve the long term goals that really matter.

That is one of the most important things about this course, and it's why it tends to have a much more direct impact than many others. We put an emphasis on the things that really matter - one does not have to create pretty drawings in order to pass a lesson, and one does not have to demonstrate mastery of any specific skill to continue forward either. Students are only ever held back if their misunderstandings are significant enough to require that the student be able to demonstrate that they understand now.

Before I call this done, I wanted to provide you with one additional diagram/set of notes - although this is more for the sake of completeness, rather than you specifically requiring them. Your work on the last texture, the one on this page actually shows what the notes address being handled very well.

When it comes to those tires with shallow grooves, or really any texture consisting of holes, cracks, etc. it's very common for us to view these named things (the grooves, the cracks, etc.) as being the textural forms in question - but of course they're not forms at all. They're empty, negative space, and it's the structures that surround these empty spaces that are the actual forms for us to consider when designing the shadows they'll cast. This is demonstrated in this diagram. This doesn't always actually result in a different result at the end of the day, but as these are all exercises, how we think about them and how we come to that result is just as important - if not moreso.

With that, I'll go ahead and mark this challenge as complete. There are a lot of points about how this exercise is to be done that you unfortunately did stray from at various points and to varying degrees - but I expect my answers to your questions should help you practice this exercise more correctly going forward, so you can continue to develop and hone those related skills on your own.