Units (Unreal)
Information regarding the types of values used in Unreal Engine is a crucial yet often overlooked area at the beginning and even later down the road.
You can usually get a few days into development before the inevitable conversion monster visits you. It has many common forms: a house-sized human, a human-sized house, and a hidden object (My Favorite).
Overview
| Type | Unit |
|---|---|
| Distance | Centimeter |
| Mass | Kilogram |
| Angle | Degree |
| Velocity | Meters Per Second |
| Force | Newtons |
| Light | Candela |
Unreal Engine uses mostly metric units by default but can change to several other options. The selected units will influence the engine and your pipeline, such as model importing and coordinates.
Knowing the unit type when doing specific tasks is essential. Trying to troubleshoot a missed channel trace because you mixed up the distance units with Meters instead of Centimeters is never fun.
Most of the units are the usual except for Distance and Light. These are a bit off standard and could cause some issues if not careful.
Default units can be changed in the project settings. (Edit -> Project Settings -> Editor - Appearance)
Unless there is a specific reason to switch unit types, staying with the defaults is best.
Distance
Distance units are used in many places, namely the Location variable in the Transform class.
It is easy to run into issues due to the default being Centimeters.
Most Modeling programs work in Meters as their default unit; this requires some conversions when importing objects into the engine.
