I also need to only change the measurements system to metric (the international). How to do it? Editing some config file?

java -jar /usr/share/java/sweethome3d.jar -Dcom.eteks.sweethome3d.j3d.checkOffScreenSupport=false

Doesn't work.

Arch Linux, jre8-openjdk 8.u66, sweethome3d 5.1