three.js - ThreeJS Minimum screen width for a single object -

i using similar project example: https://developers.arcgis.com/javascript/latest/sample-code/scene-external-renderer-threejs/index.html

this application displaying 3d object (iss). if zoom out, object gets smaller (logical), want have minimum size object. want object take @ least 10 % of screen width.

how can achieve goal?

i don't want restrict camera movement metods, want enlarge object itself.

to working need:

1. compute bounding spehre on geometry of object using boundingsphere (geometry)

2. project bounding spere (example of projection: converting world coordinates screen coordinates in three.js using projection)

3. check if pojected object width not less 10% of window width.