Unreal Engine 5 brought about significant sweeping changes and many new additions. One of those changes is the Large World Coordinate system that introduced support for double-precision floats throughout the engine.
In Unreal Engine 4, a float represented a 32-bit floating point data type. This data type was limited to roughly seven digits. A double-precision float represents a 64-bit floating point data type with a limit of roughly 16 digits.
To clarify, double-precision floats have been a part of the engine for a long time, just not natively supported in-editor and many underlying systems until Unreal Engine 5.
With the addition of proper double-precision float support, this allows multiple systems to become way more accurate as it can hold more than double the data. And the main reason for the addition is to support large worlds (thus why it’s called Large World Coordinates).
In Unreal Engine 5, all float variables will be double-precision. When the blueprint is compiled, the float will be casted to either be a single or double floating point number based on it’s value.
If you’re upgrading your project from Unreal Engine 4 to Unreal Engine 5, the 32-bit floats will automatically be upgraded to 64-bit floats.
Double-precision floats are a huge deal, but only if you’re pushing the limits of your Unreal Engine world.
If you’re interested in learning more about variables in Unreal Engine, check out my article — Blueprint Variables: What you need to know — as I cover every aspect of a blueprint variable.