For anyone interested in exploring Godot are working on a json spec for 4D Shapes for rendering and physics -- it's called G4MF (Good 4D Model Format) loosely based on Khronos glTF -- still a work in progress but there is playground editor support for x/y/z/w
Thanks! I didn’t know about G4MF — looks cool. What I’ve missed more often, though, is 5×5 matrices for real 4D transformations.