[nhatbui]

What application can I use to generate those JSONs for the models?

[alex2401]

For the models you may generate their file with blender or other 3d editing tool.

But if you mean things like spheres, boxes, tetrahedrons and others - you may write them manually, isn't it easy(?)

It's 50% chance that we will make an editor for it (cause it will be super easy with such API)