I went and quickly modeled basic shapes of all the polyhedral dice, I have included the step file so they can be imported into Fusion 360 or a compatible program to have logos, numbering or whatever else added to them.

The sizing of the dice is (face to face):

D20: 20mm

D12: 18mm

RD12: 16mm

D10/%: 16mm

D8: 15mm

D6: 15mm

D4: 18mm (base to point)