How (And How Not)(Actually Mostly How Not) To Draw 3D Intersections

Posted by pladd on March 12, 2016

Paul drew more intersections! Look at that image up there. Those words are definitely representative of all of the intersections I drew. They all look perfect and wonderful and great. Gosh golly what a good job I did. I can promise you that none of them look like this:

Okay, fine. So I may have made one mistake—

Okay maybe more than one—

FINE. Lots of mistakes.

See, last time, it was just boxes. Boxes are easy, which is why I didn’t mess any of them up.


Anyway, the obvious problem is that three-dimensional forms aren’t limited to boxes. People aren’t made of boxes. If you are made of boxes, seek help from a medical professional.

When you start bringing three-dimensional curves into the mix, things tend to get complicated. And when you have curves intersecting with other curves, things get cray. Pardon my French.

Of course, this is all part of the whole “learning” thing. I’m supposed to make mistakes! And, since I’m working entirely in ink, those mistakes will sit on the page and stare me in the face, forcing me to acknowledge them. “Hey, Paul!” they chirp, like chicks in a nest. “We’re ugly and it’s your fault! Our existence is a nightmare. Why did you create us? Please, have mercy!”

I am, of course, happy with some of the intersections I drew, and the exercises definitely got me a lot more comfortable with trying to draw in three-dimensional space. But why dwell on the positives? Let’s go into the major mistakes I found across all of my intersection exercises. As always, here are the links to the full pages: one, two, three, and four.

Mistake 1: Bad, Bad Ellipses

This is entirely a mechanical practice issue. Look at this thing:

What are you doing there, faint line? Why are you in the middle of the circle? Nobody knows, except that I know, and it’s because my arm sometimes jerks when drawing round shapes instead of moving smoothly.

Sometimes this isn’t an issue, though. Check out this bad boy:

That is one tight ellipse. That bad boy is tighter than a tight end closing a pickle jar too hard while crawling through one of those claustrophobia-inducing tiny caves.

I just need to practice more. Right now, all of my warmups consist of straight lines, so I should probably throw more ellipse exercises in there.

Mistake 2: Not Drawing Ellipses At All

“Oh, Paul,” you’re saying, shaking your head like a disappointed father. “You just talked about drawing ellipses. Go home, you are obviously drunk on drugs.”

First off, let me say this: You’re not my real dad! I hate you!

Secondly, I both did and didn’t draw enough ellipses in these exercises. See, when a flat plane intersects with a curved surface that it loves very much, its intersection looks like an ellipse drawn along that plane:

So when a curved shape intersects, it can help a lot to actually draw the resulting ellipse. And I did that!


I think I got scared of the aforementioned Ellipse Instability (dibs on the band name), so I decided to just take a stab at the intersection line without drawing the entire ellipse, with mixed results. Same root problem as Mistake #1, just manifested differently.

Mistake 3: Too Much Heavy

Since I’m drawing all of the shaped before figuring out where they intersect, I need to draw all of every shape. Which is fine! One of the major goals of this exercise is to draw 3D shapes that feel like they correctly coexist in the same space without looking weird. (See this example from Draw A Box - it’s a really subtle mistake that I probably still make.)

So I drew the entirety of each shape, but I’m not really very subtle with my linework yet, so lots of the lines ended up at Maximum Heaviness from the start (dibs on the band name again).

Why is that a problem? Well, when I come in later to draw the intersection between two Maximum Heavy shapes, it’s really hard to visually distinguish the intersection lines from the shape lines. Let’s bring this guy back one more time:

The combination of this mistake with Mistake #1 makes it hard to tell that there even is an intersection. You may have noticed that some of my intersection lines are SUPER MEGA dark, which was my attempt to offset this mistake. And some of those attempts resulted in the final major mistake I see:

Mistake 4: Straight-Up Drawing The Wrong Damn Line

Look at this so-called “cone.”

“Why did you not stay your hand?” rings its plaintive cry in my ear. “You could have stopped this! You could have stopped this.

Sometimes my attention just up and wavered. My willpower failed. “No need to ghost my lines,” I said to myself. “My arm has had literally hours of training, there’s no way I could possibly screw up OH NO AH NO WAIT AHHHHH”

Sometimes this would even happen when I was attempting to darken an intersection to make it “pop” against the existing form lines. I would stop paying attention and just draw on the pretty lines, and then look back and realize that I had just reinforced a line that was specifically supposed to be ignored:

And now your brain doesn’t know which line is real and which one is fake. Reality falls away. Left is right, green is red, your hands sweat without provocation. Welcome to every day of my life.

In Conclusion

I’m almost done with the “basics” section of Draw A Box. After this, I’ll progress to the “try to draw actual real life things with what you’ve been taught” lessons. If I just continue to not ever make any mistakes at all, I should be golden.