Units and Coordinates in Holodeck

Holodeck uses meters for units and a left-handed coordinate system for all locations, distances, and offsets.

Coordinate System

Since Holodeck depends on Unreal Engine, we use a left handed coordinate system with positive z being up. This is something baked deep into the engine that we can’t easily change.

So, when you need to specify a location in Holodeck, the format is as follows

[x, y, z] where:

  • Positive x is forward
  • Positive y is right
  • Positive z is up
../_images/axis.png

Remember that the units for [x, y, z] are in meters (Unreal Engine defaults to centimeters, we’ve changed this to make things a bit easier).

Rotations

Rotations are specified in [roll, pitch, yaw] / [x, y, z] format, in in degrees. This means

  • Roll: Rotation around the forward (x) axis
  • Pitch: Rotation around the right (y) axis
  • Yaw: Rotation around the up (z) axis

(source)