I’ve learned that video game ‘clipping’ is caused by high velocity, thin colliders, and too-slow physics updates. Why are terrain surfaces in most 3D video games paper-thin? Why isn’t terrain given extra fill/thickness inside and under it to prevent ‘falling through the map into the void’?

Question

I could see why you might not want to fill under the terrain in a game that features things like underground caves, but thin terrain seems to be present in a huge majority of 3D games (even those without underground features) and is not engine-specific. Why is terrain almost always a fragile piece of origami that’s so easily punctured?

In: Technology

Answer 1

In the 3D world there is no such thing as actual, solid thickness. Take a look at [this image](https://i.imgur.com/aX3YNKQ.png)

The first shape is a single flat plane. You can “thicken” it if you like (second shape), but in reality, if you actually looked inside it, you’ll see it is still hollow (third shape).

So if you try to thicken the terrain, you’ll only be adding another thin plane underneath it, not actually thickening it.