BenjaminTuttle (11/7/2019)
One thing that can be done is simply make a meter cube.
iClone's built-in Box shape is actually suited for that, as it has sides of 1 meter.
EDIT: There is also a free ruler in the Market Place:
https://marketplace.reallusion.com/ruler. It's in feet, but you can make it metric by re-texturing.