I have no idea when I read Paul Watzlawick’s How Real Is Real? the first time. I was amazed by the theories buried deep within the book and read everything I could. One sentence is still sticking – and seems to be a paradigm of my thinking: One cannot not communicate.

I nearly forgot this sentence, when I raced through visualisation books for my master’s thesis some years ago. Human perception is reliable: One cannot not see 3D. Let this sentence sit. And then think about the modern flat design which is everywhere nowadays. Everybody is talking about this, but most of the people have no clue that their idea of flat means that it is not 3D. Which is actually wrong…

Here is why:

Let us make a small detour and think what seeing and perceiving 3D means. According to Colin Ware’s Information Visualization, Third Edition: Perception for Design (Interactive Technologies) there are plenty of hints for depth which all somehow rely on occlusion. Think of occlusion as one object in front of another and therefore blocking your view.

What are those hints?

1. Stereo vision: basically meaning you use two eyes and their pictures overlap. Not everybody has this ability, but still can see in 3D! Flat design tries to omit these hints.
2. Kinetic depth: By moving an object you see different parts of it. The widely used parallax effect (things in the background move slower than objects in the foreground) can also be seen in this category. Parallax effect tries to give back the order by depth in flat design.
3. Vergence: This wonderful word means changing the way the eyes are positioned to focus on an object. Hold your finger close to your face, than look into the distance and back again. Your eyes changed angle. I have no idea why I have it in this list. It has no meaning for flat design.
4. Perspective: Lines running toward a point are the obvious hints for perspective. In flat design this principle is omitted by using isometric models or 2D drawings.
5. Texture gradient: You could call this gradient the perspective effect for areas. Because the perspective is omitted this hint is also.
6. Shading: Flat design omits shading gradients, but you can find super subtle gradients in recent works. The gradient is due to lighting which would give that unwanted plasticity. I have to admit that I am in love with the subtle gradients…
7. Shadow: If something is flat it has no shadow hence the absence of shadows. Often the shadow is reintroduced as a stylistic element – but always in the form of a hard shadow, not a soft or blurry shadow.
8. Depth of field: Human perception is limited by optics – there is a zone where you can focus and you cannot do anything about it. In flat design you have no blurry background. But what you have are other depth of field effects: Objects which farther away have less detail or are of lighter hues – think of haze.
9. Occlusion: Occlusion is the king of 3D. All the other hints are just additional clues which add up. It is also the simplest thing and works all the time. Even the black letters you read right now are nearer to you than the white background.

So there is no way to not see 3D, flat design is actually 3D and clean, because you human perception cannot change the way it works and light is everywhere. And we haven’t started talking about colors…

If you spin this idea into an extreme. Every 2D thing is 3D because you are hard wired. Now let’s throw in Watzlawick again and think of communication. Because there is definitely a person who wants to tell you something with their design. So when the 2D/3D fails the communication will fail.

Flat design was just an extreme after the era of opulent graphics. It was definitely paving the way for something else. What was it? Maybe it was the beginning of subtle effects. What do you think? Where will this road lead to?