Let me propose another solution. If you want fine grained control on positioning the annotations I suggest to add markers in the GLB (or whatever format you use).
Example for Blender:
Parent your mesh with an Empty (becomes a TransformNode in babylon.js).
Add an Empty for each your annotation position. I added two, one in the corner of the cube and one in the middle of one side of the cube,
Name this Empty objects as you wish. I used 1 and 2.
Then use this code to attach the annotations:
With this approach you can absoutely precisely position your annotations even on complex meshes. And they naturaly follow the transformation of the mesh. The code is mucb more simpler and readable.
