For me, the prime instance of that is Outer Wilds. Nevertheless, it applies to different related video games. Within the recreation, the participant explores a photo voltaic system. This has the next implications:
- We now have an enormous house to discover.
- There are planets are shifting on a regular basis anyway.
Since the whole lot is shifting anyway, then shifting the whole lot as an alternative of shifting the participant character isn’t actually an additional value.
And why would you wish to transfer the whole lot as an alternative of shifting the participant character? As a result of floating level precision.
For instance of the issues that floating level precision brings, allow us to see a recreation with enormous worlds that doesn’t do that: Minecraft. See THE TRUE END of the MINECRAFT WORLD!.
As you progress away type the origin you’ll begin to see issues.
It’s because floating level numbers can symbolize extra values close to zero than away from zero.
In case you aren’t aware of how floating level numbers work, to begin with, listed below are a pair movies: Why Computer systems are Dangerous at Algebra | Infinite Sequence and Floating Level Numbers – Computerphile.
Nevertheless, for the needs of this reply, you’ll be able to consider them as a scientific notation (with a mantissa and an exponent), or you’ll be able to consider it as shifting the decimal level (therefore the identify). These are the identical concept: Because the exponent turns into bigger, you might be shifting the decimal level to the precise, in order that there are much less digits after it.
Thus, the primary symptom is that movement turns into jittery. It’s because the distinction between a floating level quantity worth and the subsequent turns into giant sufficient that it’s noticeable. Due to rounding, movement continues to be posible, however not clean.
Ultimately there there aren’t any digits after the decimal level. And you then preserve shifting the decimal level (i.e. rising the exponent), and the floating level numbers start to skip integers altogether. Once you attain these values we have now one other attention-grabbing conduct: a floating quantity worth plus one is identical floating quantity worth. As a result of the subsequent integer can’t be represented as a floating level quantity, and is rounded down.
I remind you that the hole between values that may be represented turns into bigger and bigger. So for any hole you’ll be able to consider, there will likely be a place the place the hole between values that may be represented is bigger… Nicely, ultimately you attain the bigger quantity that may be represented, and that’s that.
What I am going with that is this: ultimately the gap that the participant character would transfer is simply too small to make the hole between values that may be represented, after which the character cannot preserve shifting.
And, in fact, for some other system that is dependent upon the place in your recreation (e.g. movement, fashions, lighting and shadows, world era, and so on) the progressive lose of precision as you progress away from the origin will introduce weirder and weirder conduct.
To keep away from all that you just wish to preserve the participant character close to the origin. And that will imply to maneuver the world.
