Randomize spheres in a specified area

 From:  Frenchy Pilou (PILOU)
10037.16 
If you want a complet tuto about MS Physics (for SketchUP) take a look at this ;)
26 little videos :) ps Sketchup is 10 times more easy than Blender! :)

EDITED: 22 Nov 2020 by PILOU