Game Development Stack Exchange is a question and answer site for professional and independent game developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

This may be a silly question but I want to know the answer to it. I saw this thing called the "impossible object", while they're many different images of this online, it's suppost to be impossible geometry.

Here is an example:

enter image description here

Now as far as logic goes, I know you don't have to obey it in games, such as a flying cow, or an impossible object. So that's out of the way, but what stands in my way is whether or not there is a way to draw this onto a 3D scene. Like is there a way to represent it as a 3D object? Thanks!

share|improve this question
Sure.. just disable z-buffer and mess up the sorting order, and voilá, you have that object.. =) – Jari Komppa May 27 '13 at 5:49
I've done this, only I called it "the horrible mistake, gimme a sec to fix that" =) – Patrick Hughes May 28 '13 at 0:54
up vote 10 down vote accepted

3D computer graphics works based on the mathematics of 3D space. Objects like that cube cannot exist in 3D space - that's why they're "impossible objects" - so they cannot be directly modeled in computer graphics either.

Of course it is possible to build objects that, when seen from a certain camera angle, produce an optical illusion that makes them look like an impossible object.

Penrose stairs in Inception

Or as Jari Komppa commented, it's possible to render things "incorrectly" (mis-sorted for example) and make things look like impossible geometry that way. And there are games that play with 2D/3D perspective deliberately, such as echochrome, Fez, and Perspective.

share|improve this answer

Sure you can, just modify the geometry as the player goes through.

There was a game called Antichamber that was built entirely around this idea, where the maze changed as you went through it.

So like you start at this point right, where you choose which dir to go

enter image description here

You go up the stairs,

enter image description here

Turn the corner,

enter image description here

Then end up back at the same point

enter image description here

Physically impossible, done with (apparently portals as Nathan says in this post)

share|improve this answer
That sounds like Antichamber. – Nathan Reed Nov 9 '13 at 20:51
Yes, I read the name in your other post, thanks Mr Nathan – bobobobo Nov 9 '13 at 21:33

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.