`Scene` coordinate system is y-up, right-handed

In general, this space conforms to expectations from Three.js
An infinite three-dimensional space
Floating-point coordinates define each of the three axes
Center of the space is at 0,0,0
Annotations (of any kind) can exist in this 3D coordinate system, with an associated position to be defined through other user stories.
Three.js coordinate system is +Y up and right-handed (+Z pointing toward viewer)

IIIF / api