# Thread: Assignment 3 & 4: Cubes

1. ## Assignment 3 & 4: Cubes

Post the results of assignment 3 & 4, the cubes, in this thread please. This thread is for my mentees only, unless you've got any tips or hints to share. I won't react on your work if you're not one of my mentees. Thank you

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Assignment 3: Cubes

This will actually be the first real assignment complete with deadline and all Now that we have the basic idea of lines and perspective behind us, we can start the drawing of shapes in perspective. I'll start with cubes. The reason for this is simple, by combining cubes and some of its cross sections you can already make quite a complicated drawing. Cubes are often used to keep proportions and measurements in check, as foreshortening makes it sometimes difficult to judge these without them as guideline.

You can already get an idea of what I'm going to ask of you in the sketch above, but I'll now explain how to get there in a few simple steps. The reason I want you to follow these steps is that they provide a good way to spread decision making in your drawing. Unlike a mere block shape, cubes have more rules For one, a cube measures the same length on all of it's ribs. This makes them ideal to use as a check for proportions. However, judging whether a cube is actually a cube takes some training.

Above you see 6 steps in which I want you to try to follow through until you end up with the cube. If you feel uncomfortable following these step by step feel free to come up with your own order, but in my experience this works quite well to begin with.

Step 1: Start out with drawing the vertical front rib of the cube. The length of this rib defines the total size of the cube, so you can just put two points on it already to have a guide for the rest. Then, draw a horizontal line on the lowest point. This line doesn't exist in reality, and after you got some cubes down you may drop it completely if you like. The reason for this line becomes clear in step 2.

Step 2: Draw the two base ribs that rest on the ground. Make sure there is an angle between them and the horizontal line you just drew, otherwise you'll end up with a cube in sideview without any perspective. Also, make one of the two angles larger than the others, check with the examples below for the why This difference in angle means one of the sides gets more foreshortening than the other. You can choose to make either Alpha or Beta smaller or larger, that is up to you.

Step 3: The next step is to draw one of the two vertical ribs on the corner right or left. It is easiest to start with the side that has the least foreshortening. The place of this line has to be guessed, because as this is not a perfect sideview, the side of the cube will have some foreshortening (and thus appear smaller). To help judge these though, you can measure the length of the front vertical along your pen and then measure the horizontal distance between the two verticals. This should be somewhat less than the total height. The bigger the angle Alpha is in my drawing, the shorter the side will appear to be. Keep in mind that in the end, each side must appear to be a square in perspective.

Step 4: Next step is similar to step 3, now take the more foreshortened side and again, judge the horizontal distance between the lines.

Step 5: Now add the two 'horizontal' lines on top, this way you close the first two sides of your cube. Keep in mind the story about perspective I put up above. Step 4 and 5 are interchangable, you can start finishing one side before going on or you can do it the way I did it.

Step 6: Now finish the cube. Draw all the lines, even those which you can't see. This will be very usefull and even necessary in coming assignments. Again, take the perspective and vanishing points into account. As you can see, I made several mistakes in this drawing but instead of starting over or erasing parts, I simply drew another line to correct my mistake. At this point you might also find some of the points found by the crossing of perspective lines will not line up properly (see the rear vertical rib, it doesn't really end at the crossing of the two rear horizontal ribs at the top). This is fine, as making a perfect cube isn't easy. When you see this happen, try to make your own estimate and see where you can adjust the lines to correct it.

Step 7: This would be the result: a nice cube I toned one side with my C3 marker, just to punch out the shape a bit more. I also made the lines where the cube sits on the ground a bit stronger, as a sort of shadow. This works to make the drawing a bit more 3d. In this example you might already have noticed how important the training in line thickness and straight lines is.

The figure above is to show some examples of, well, not mistakes. But drawing a cube like one of those might give problems you don't want, so try to stay away from these if possible.

You may notice that I do draw the lines slightly longer than need be, and I also start slightly before the actual starting point I need. The reason for this is that it prevents you from doing the opposite. If you do not draw all the lines up to the point you want them to go, you lose information an clarity in your drawing. If you need for example the diagonal line on one of the sides of the cube, you need to make sure it passes through the right point. If you do not draw it through that point but stop somewhere before that, it doesn't always read very well where the line originally came from.I advise to always draw the lines all the way through and even a bit longer than that.

Another important aspect, draw big. This forces you to practice your lines etc. but also gives a better opportunity to correct your drawing withouth having to erase anything or start over. If you draw too small, the drawing will easily become full of lines that start to obscure the actual form you're trying to get across. Try to make all the drawings for this about handsize. This means aim for something roughly 15cm x 15cm.

Now, the first real assignment is for you to draw a couple of cubes. Take about 10-15 minutes for each cube, and make it a total of about 6-8 cubes on one sheet. They all have to be a cube, so no block shapes or anything, but cubes. Also, put a tone on one side like I did in the example nr. 7 (I'll explain more about shadow etc. later on). Then, when you're done with them, put a circle around the two you think are the best cubes. This way you also learn to judge your own drawing. To be delivered in this thread before Saturday 26th.

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Assignment 4: Cubes as a guide for construction

This is the follow up of assignment 3, as that one shouldn't cost you too much time. Now, we'll see that with only a simple cube we can already do quite complicated stuff. Part of drawing these constructions is actually very close to -if not just plain- mathematics.

Below you'll see how we go from a basic cube to a whole range of cubes in the same perspective. Funny thing I noticed, these cubes are all exactly the same, but when I put them in a row they seem to turn towards the viewer as you expect them to have the same vanishing point from left to right

The ability to draw straight thin lines becomes important in this assignment, as the construction requires a lot of lines and will quickly become unreadable if all your lines are thick. If you don't feel sure you'll be able to keep them all thin, try drawing the cube bigger so line thickness becomes less of an issue. Keeping the lines straight will become harder of course.

The reason for this exercise is that sometimes when you design something and start drawing it, you might need to find where certain points of your drawing are in space. You could guess them, and eventually you'll learn to do so, but it'll always be less sure than if you make the full construction. Drawing the shape into such a system of cubes is one way to do it (possibly the most difficult at that too). You won't use this construction very often, but it helps to create that feeling for where points are in space and in relation to one another.

Step 1: Start out with a simple cube. Take care that is has to be a cube and not a block shape, as this will make the construction less of use to measure proportions. If it turns out a block, it gets harder to show things like 'the object is twice as long as it is high' etc. Make the cube large, say 20cm x 20cm so as not to get problems later on.

Step 2: Now, devide the side surface into four squares. To do this properly in perspective, you need to first draw the diagonal lines in this surface. The thing with perspective is that the further away an object is, the smaller it gets. Therefore, the squares at the back should be smaller than at the front, which makes it harder to simply guess the middle. So, draw the diagonals and on the crossing of the two you'll find the middle of the cube. Now, draw the vertical and horizontal line in the surface (the horizontal one will be in perspective. To find it's direction without too much guessing, you might find it usefull to first divide the front rib in two. Since we use only 2 points perspective, this line appears without foreshortening and can therefore safely be divided into two equal halves. See point B in the drawing) Notice how line CD is longer than DE, while AB and BC are of the same length.

Step 3: Now do the same with the front surface. You might find that it already gets a bit difficult to distinguish the lines from each other as the start crossing and run over each other. This is sometimes inevitable, especially in a construction like this and might make it hard to find the right lines and points later on. Try to see through it. Also, sometimes if your lines don't end up real straight or just miss the corners, you'll have to adjust it a bit by eye. This, again is inevitable and require you to train your eye to see these things intuitively.

Step 4: Repeat the steps above until you've covered all sides of the cube, including top and bottom. Notice that if your point of view is too low on this one (i.o.w. angle Alpha and Beta are too small as seen in assignment 3) you'll have a hard time doing so in the top and bottom surface. We're almost done now, we just need a few more lines.

Step 5: Now devide the cube down the middle as well by drawing the three crosssections as seen in the last drawing above. You already got all the information you need to draw these surfaces from the construction on the sides of the cube, but to be on the safe side you can still add the diagonals as well to find the exact middle of the cube. As you can see, the construction has already gotten quite complex while we're still only talking about a simple cube. In the last figure of this assignment you'll see it gets much better readable again by applying some shading.

The above method is a construction from the outside in, and works well to minimize mistakes in the initial cube. Another method to draw the same figure is by starting out with a small cube and multiply it with the following constructing method. The problem here is that you also multiply any mistake in the original cube, so you might end up with a worse result than above.

Step 1: Again, start out with a single cube. This time make the horizontal lines in perspective longer than really necessary, as you'll need the extra length later on. Now, divide the rear rib of the cube into two equal halves (point A). Since this line doesn't have any foreshortening, this should be eay

Step 2: Draw the diagonals through A from both point B and C. You actually only need one of those, as you'll see that line BD is much harder to get right (it's longer and if only you miss the right spot D the differences are much larger). Line CE is the most accurate as it minimizes any mistakes.

Step 3: Now you can draw the second cube behind the first with help of the point you just found.

As you see in the image above on the left, putting some tone on the drawing immediately makes it much easier to read. This is an easy method to cover up any mistakes, or even to show one cube is missing! I did this by simply choosing to put shade on a different surface which I had already found by the earlier construction. Note that even while I originally constructed the whole cube, by putting the shade on the right spot you're able to make things in your drawing 'dissappear'. It is often important however to still construct the whole of the shape, as the lines I now do not use still tell a lot about the overall shape, even while they're not supposed to be there.

On the right you see the actual assignment: Start out by drawing the cube in the fist part, then substract one cube from the total as I just explained. Add another cube to the back or front, choose you're own side I'd say. And last, put another cube on top of it all. How to do that is up to you to find out (it's not difficult at all )

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Deadline on both is Friday 25 January.
Last edited by yoitisi; January 29th, 2008 at 06:07 PM.

2. About how big should the cubes be?

3. Asmodie: I think I said something about that in one of the assignments, but for clarity: they should be about handsize (15cm x 15cm) each, which means you can probably fit 6-8 on one sheet of A3. I'll repost the assignment in this thread as well I think, so it becomes a little easier to get to it.

4. ## Assignment #3 - Practices

Worked on some cube practices this last night. Going okay I think, but I need some more definition when drawing each line, currently they end up a bit scribbley.

Would it be right to say that the length of the angled sides is comparable to the ratio between the angle A or B and 90°. So a 45° angle is half of the total 90° so the length of the angled side will be half that of the vertical?

5. Don't worry about the handwritten words. At the top I was chiding myself for selecting the wrong point of view. The writing on the second sheet is about how that one cube has the most cubelike dimensions, but I fouled it up by making the lines all wonky.
Last edited by arttorney; January 21st, 2008 at 02:33 PM.

6. I put up the rest of the assignment for this week, so you don't have to get bored I'll comment on your work later on.

One important note, and I realised I should've said this earier: If you draw lines for cubes and the like, you might find it useful not to follow the points to strictly but start the line somewhere before it and don't stop right on the point you're aiming for but draw through it. An example mentioned in the thread for assignment 1 & 2 was the golf-swing. Don't stop swinging the club the moment you hit the ball but continue the swing. There's a couple of benefits here, first that the lines tend to be more on target and second that your drawing will look more alive if you draw this way.

7. I made another six cubes. I'm still making them taller than they are wide. Concentrate though I may, I can't seem to invest more than 5 minutes per cube. At least this photo looks more clear.
Last edited by arttorney; January 21st, 2008 at 02:34 PM.

8. Am I correct in interpreting step 5 as calling for a subdivision of the three internal planes similar to the vertical internal plane I bolded on that pathetic attempt I labeled "First try"? When I made "first try" I didn't really get that last step, but then I think it dawned on me while I was making "2nd try."
Last edited by arttorney; January 21st, 2008 at 04:57 PM.

9. This is my attempt at lesson 4. I prefer the subdividing method.
Last edited by arttorney; January 21st, 2008 at 02:34 PM.

10. Arttorney: Good to see you're already pouring some work out I'm currently damn busy because I've got several deadlines that are killing me, but I'll comment as soon as I can.

11. Assignment3. Drawing cubes is different from those straight line practice, it's more difficult when you don't have more chance to get your hand to used to the line. Those two cubes aren't even cubes I think.

Assignment4. I had redrawn it about 5 or 6 times to get it right, yet the work just got messy while I was trying to draw another line to replace the wrong one. As the instruction of the assignment, the result has almost been decided when you place your pen onto the paper in method2.

12. No hurry Yoitisi. Because of work (and my 6.5 hour drive home next Friday) my choice is turn in early, or turn in late. I am not a big fan of the "turn in late" option.

I know what you mean Unsharpened. The cubes are humbling. I used to think I could sorta draw.

13. The third assignment...here it comes.
My scanner screwed with the colors.

Last edited by yoitisi; January 22nd, 2008 at 01:13 PM. Reason: attachment

14. Some of the parallels lines I did are seriously off
Also, I just used my pen for a couple of days and it's line start fainting like it is running out of ink.

Last edited by yoitisi; January 22nd, 2008 at 01:15 PM. Reason: attachments

15. I completely agree with you arttorney. These really made me feel like I couldn't even draw cubes. Yet a good thing is that I found it's a useful practice for pre-planning the work you are going to do, otherwise it only ends up with catastrophe.

16. i keep making them too tall, definitely harder than it looks.
i'm gonna make some more later. yoitisi, do you prefer if i post them in this same post or in a new one?

Last edited by yoitisi; January 23rd, 2008 at 06:16 AM. Reason: attachment thingy

17. This assignment made me realize how sucky I am.
I think I threw away about 10 sheets for this one. And I'm still not satisfied.

Last edited by yoitisi; January 23rd, 2008 at 06:17 AM. Reason: attachment thingy

18. Allrighty, time for some comments here It's going to take me a while I'm afraid, so I might do it in more than one session.

First of all, its good (in a way) to see you find yourself struggling with something as 'simple' as a cube. This is perfectly normal, so don't be afraid that you totally suck or whatever. You won't anymore after we're done here. This stuff simply takes practice and practice and then some to get down properly. I've gone through the same process in my first year, and sometimes I really hated to pick up my pen simply because I was being humbled by my own incompetence However, if you keep following the exercises and keep studying them you should be able to do these damned cubes in your sleep.

So, now for some hands on crits:

D-Holme: You're right there, the length of the angled sides does relate to the angles Alpha and Beta. It might be handy to keep in mind when drawing and evaluating these cubes, but there is a little snag: the estimation of angles is rather difficult for the human eye (as I've seen by many students). To put a number on any given angle is quite hard, and now imagine doing that when you do no longer draw the horizontal. About your cubes, I think the middle left and middle bottom are the better cubes, just take care that you don't lose the rear rib behind the front rib of the cube (iow: don't make A and B the same angle).

Arttorney: What I liked to see about your work was that you improved with each post In the beginnig you made all of them too tall indeed, but the subdivided cube looks like a proper cube to me. Your right that that method results in a better drawing, but it also cost more time to do in most cases. One thing though, if you find you drew the cubes to high try to correct it in the drawing itself before making a completely new cube. Don't erase the initial lines, but just draw in the right lines on top of the old ones. This is much easier to start with because the basis of your cube is already there. Then draw a new cube and try to implement what you saw on the last one. Also, keep an eye on the (virtual) vanishing points, in some of the earlier cubes the lines are off by miles. Then again, the last couple are an improvement on this.

Unsharpened: You're right, whats more I thing both cubes at the right of the ones you marked as 'cubes' are actually better Judging your own work is an important aspect of these exercises. As with Arttorney though, the last one is an improvement even though it took a couple of tryouts. Keep an eye on the perspective, as even in that last one some lines are dangerously close to be parallel to each other rather than converge to the same vanishing point. For the multiplying method, make sure you take one of the side surfaces and not the top or bottom! Only the vertical lines can be divided precisely into two equal halves as they have no foreshortening towards a 3rd vanishing point. The lines to the vanishing points to the left and right do, which means the middle of the rib isn't the exact middle of the line that represents that rib.

Hamtaro69: Your lines look good You tend to make the same mistake in most of these cubes though: the side with the most foreshortening (where the angle A or B is largest) is too long. In the last one (bottom right) you corrected this, but when looking at the top surface it still looks too long. This has also got to do with the perspective, which is a little off on the rear ribs. In some of the other cubes the perspective is there but you made the cube too long again. Try to combine this into one perfect cube

Okay, time for some food here. I'll continue later on.
Last edited by yoitisi; January 23rd, 2008 at 11:11 AM.

Asmodie: I think the middle one at the bottom in your first cubes-post is indeed the better one. It misses a line but that might be caused by the scanner. One thing you must watch out for is that you choose both angle A and B very large, which makes that you see the cube almost from the top and then you should actually start using the third vanishing point as well. Choose either A or B a bit sharper so you see the cube a bit more from the side. As soon as the angle between A and B (the one that completes the full 180 degrees) becomes about 90 degrees, it means your floorplane of the cube becomes a square which in turn means your looking at it straight from the top and you wouldn't be able to see any of the sides. The last cube construction goes wrong because the initial cube isn't a real cube. What might help is to first draw the cube and correct it untill it really is a cube no matter how many lines you need. Then take out a new sheet, put it on top of the first cube and copy the cornerpoints of the underlay. Then draw the lines in between much like the first assignments, and you have a solid base to make the construction. This way it costs you less paper, effort and time, and you end up with a better result. Don't go and copy the whole cube though, as this will inevitably result in wonky lines I can see it if this happens.

Enrigo: Yeah if you use your fineliners frequently you might need a lot of them because they do run out of ink and tip fast. A couple of days is a bit much though, are you sure you don't press too hard or dropped it so the tip dissappeared? Your cubes look okay, although most of them tend to be either a tad bit too high or too deep, but that'll get better the more you do them. Do watch out with the perspective though, you might want to check on the vanishing points in the one at the bottom left. Maybe try a couple without the horizontal starting line as well, just to see if you can pull it off.

Pomegranate: A single post is preferable, as long as I haven't commented on them that is. If you are going to post new stuff do it in a new post as I commented on your first now Most of your cubes look indeed a bit too high, although the one on the far right in the middle looks okay as well, but I agree that the one with the circle around it is the best. Just keep practicing them to train your eye and arm to get the shape right. The perspective seems to go okay.

So far I've missed a couple of people in here, post your work if you got some. Would be great if I don't have to comment on it all in one go at the end so spread the workload for me please 8) Also, this is not something I recommend you rush on the last day as you won't get as much out of it as you could by doing these assigments on a regular basis. People I miss in here (correct me if I'm wrong): Legato, Ixupi, Lez, Jorge Gecov and form2function.
Last edited by yoitisi; January 23rd, 2008 at 03:00 PM.

20. Thanks. I needed to be told about the virtual vanishing points. Any improvement there was probably not the result of conscious design.

21. Hi!
Here is my results.

22. Here comes more cubes. Liked this way better..

23. had to wait till today to scan these in at school *shakes fist at traditional artwork*

did love the markers though, and oddly enough i apparently suck at doing cubes the right way, and consistently made better ones by eyeballing and free-handing them rather than doing all the guide line stuff :/

(my usual server seems to be acting up atm, so lets see if my domain can host these)

Last edited by Legato; January 24th, 2008 at 04:19 PM.

24. ## Blocks & stuff....

A couple of quick block studies - not brilliant, it would have helped with the first one if I'd given the base angle more variance (as was mentioned before but it seems to be my particular heel)- idea is there though. Up to my eye but I'll try and get some more complete practices done for the end of tomorrow.

Edit: Added up some more practice pieces - not any better then the first for the cubic-'network' but I understand the idea, I'll just have to give it some more practice.
Last edited by D-Holme; January 29th, 2008 at 06:12 AM.

25. Lez
Marcus Albertsson Level 1 Gladiator: Andabatae
Join Date
Jan 2008
Location
Arvika / Sweden
Posts
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Wasn't able to upload the project yesterday due to the downtime... Will get it up asap

26. As CA 4.0 is still under construction and the site is sometimes down, I think I'll shift the deadline to monday so everyone has a chance to put his work up. I'm still missing a couple of people...

I'll put up the next assignment soon as I can, but apart from CA being down I have to finish an animation this weekend so it might not be until monday I'm afraid. After that things get easier here so I'll have a little more time to keep this going

27. Here's my second part of the assignment.

Are there any technique to get the parallel lines right ? I have a lot of problem getting them to look right.

28. I think I'm simply going to close this thread tomorrow when the deadline is over instead of leaving it open so people can keep posting, just to keep things tidy in here. If you haven't posted your exercises yet, do so quickly or face eternal doom!

I'll try to set up some further comments later on, as well as the next assignment. I think I have some time tomorrow to do so. I'll change the order of lessons a little bit because I realised we need to do ellipses first before we go on with fun stuff

29. Yey....ellipses...looking forward to the next assignments
Still drawing cubes...did I say I owned the DNS cubicempire.net?

30. Yeah, ellipses, they are the most deceiving thing ever. I had to do one drawing of a mechanical object for my school portfolio and I picked a flashlight. I thought it is going to be a breeze, but doing the ellipses turns out to be one of the most frustrating experince for me so far .

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