250 Cylinder Challenge

1:39 AM, Sunday May 23rd 2021

DrawABox: 250 Cylinder Challenge - Album on Imgur

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Post with 19 views. DrawABox: 250 Cylinder Challenge

There is no victory here, only poorly-drawn cylinders.

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3:41 PM, Monday May 24th 2021

Starting with your cylinders around arbitrary minor axes, nice work! I'm very pleased t osee the wide variety of proportions and rates of foreshortening, and the fastidiousness with which you've checked each and every ellipse's minor axis alignment. For this section, there's just one thing to point out, in order to keep you on the right track as you continue to move forwards.

The ends of our cylinders "shift" in two distinct ways - they'll get smaller in overall scale as they move away from the viewer (scale shift) and they'll also get wider in degree as they move away from the viewer (degree shift). So the farther end is generally going to be both smaller in scale, and wider in degree, than the end closer to the viewer.

Taking that one step further, both of these shifts are manifestations of foreshortening, as applied to the form. They're visual cues that tell the viewer how much "unseen" space there is between those ends. After all, when a cylinder - or any form - runs primarily across the viewer's field of view (like from left to right), we know that we're basically able to see the full length of the cylinder. If however the cylinder is oriented towards the viewer - like we're looking down its length, as one would look down a telescope - we know there is space and distance between its ends, but we cannot actually see them on the page. It is the foreshortening instead that helps relay this information to the viewer.

The critical point here is that both of these shifts need to remain consistent. If there's a more dramatic shift in scale, with the far end being much smaller than the closer end, then there should also be a dramatic shift in degree to match. Conversely, if there's virtually no shift in degree, there should be virtually no shift in scale. Of course there will generally be a little shift (as long as there is some distance between those ends, and the form is not running completely perpendicular to the viewer's angle of sight which would result in a vanishing point at infinity as discussed back in Lesson 1), but the main thing to take away here is that the shifts need to be consistent with one another.

In your cylinders, this doesn't always appear to be the case. If you look at 128, for instance, you've got a really dramatic shift in scale, but the degree remains roughly the same. There are many others like this as well, so that's just something you need to keep in mind.

Continuing onto your cylinders in boxes, I think you had a bit of a rough start with this one, but as you progressed through the set, you did start to get some ground beneath your legs and pushed through reasonably well. The key thing that I'm seeing is that as your cylinder/box gets longer, you pretty consistently end up with lines that converge in pairs (separated by the length of the form) rather than converging all 4 together (where the lines of a given set on either side of the form converge to the same vanishing point). That's a common issue, and something to keep in mind - as that form gets longer, you're going to need to angle your lines more dramatically to have them converge together all the same.

As a whole, I am seeing that you are making good use of this exercise towards its main goal - that is, to develop a student's intuitive grasp of how to draw a box that features two opposite faces which are proportionally square. After all, these line extensions we've added with the ellipses - those of the minor axes and contact points - allow us to check whether the ellipses themselves represent circles in 3D space which rest along the surface of the box. If their lines converge towards the box's own vanishing points, then the ellipses represent such circles. As an extension of that, this also means that the plane enclosing them would represent a square in 3D space. The more we test those line extensions, and the more we adjust how we approach drawing the boxes to bring those extensions further in alignment, the more we rewire our brain to better grasp these kinds of proportions as they exist in 3D space.

Long story short - nice work! Your work is coming along well, just keep an eye on those longer boxes. I'll go ahead and mark this challenge as complete.

Next Steps:

Feel free to move onto lesson 6.

This critique marks this lesson as complete.
11:29 PM, Monday May 24th 2021
edited at 12:24 AM, May 26th 2021

Thanks, I think I feel better then?

Regarding the ellipses with the longer boxes -- I was finding that when I tried to get all the points to converge, the center line of my actual ellipse was consistently way off from the rest of the lines, so I started getting really conservative with the degree/angle of the box edges because I couldn't figure out why that was happening (and still haven't). I thought it had something to do with how the instructions highlighted ensuring that the box was properly square and not rectangular and we thus expected the cylinders to be circles for the exercise; I touched base with the Discord folks and people advised that I make my angles less extreme, thus I ended up more with the issue you pointed out where convergences are paired up instead of wholly convergent for a side (which seemed to be the lesser of two evils). I feel like I am missing something in how to achieve the actual desired result there.

I think I am also not 100% wrapping my head around the foreshortening concepts you outlined for the cylinders; I can understand the "what" (circle on far end get small and wide when foreshortening big), but a little shaky on the application of the "why"...but I think for this piece I just need to draw more cylinders in warmups and stuff and eventually it'll stick.

Thanks again for the feedback.

edited at 12:24 AM, May 26th 2021
4:07 PM, Tuesday May 25th 2021

You can think of the exercise as being broken down into two parts- firstly, there's what we focused on with the box challenge, which is simply drawing arbitrary boxes whose lines converge fairly consistently towards the same vanishing point. It doesn't actually matter if the foreshortening itself is dramatic or shallow - either way, it comes down to thinking of all 4 edges simultaneously, and considering how they need to be angled to converge together. The best way to address this is just to do more freely rotated boxes (this should already be one of the many exercises you cycle through in your warmups, so you can keep sharpening those skills).

The second part is the addition of the ellipses, which effectively tests the proportions. Based on the ellipses' own line extensions, and their relationships with the box's line extensions, you'll be able to make adjustments to which proportions you choose to use, based on the general orientation of your box in space.

Of course, if your box's own lines aren't converging entirely consistently, then that will mean you'll have to eyeball the relationship between those line extensions and the ellipse's with some margin for error. You can still of course progress through this exercise meaningfully without perfect boxes - in fact, it's not really expected that your boxes will be perfect - but it means that you have two distinct things to deal with, and remembering that they are separate issues will help you address them each in turn.

As for the why behind those aspects of foreshortening, the best explanation I have right now is in the more recently updated Ellipses video for lesson 1. Here I actually use a little prop of two cardboard discs connected by a toothpick to show how the degree of the end closer to the viewer and the degree of the end farther away will shift in degree.

The rate of foreshortening itself is largely determined by the form's proximity to the viewer and the form's own length, so in this video you don't get a lot of variation in that. You do however get to see the third factor, which is the orientation of the form relative to the viewer, with that foreshortening getting more notable as we turn the cylinder to face the camera. Hopefully that demonstration will help.

1:04 AM, Wednesday May 26th 2021

Hmm...okay, thanks. I read this a couple times, watched the video (it did help), and then cut a toilet roll in half and stared at it for a while...after that I drew a few more boxed ellipses and I think I get it a little more now.

Much appreciated.

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