On my laptop installed SH3D as per download page i.e. extracted files to / and maintained the directory structure of the archive
- checked permissions for executable and behaviour = run software
=> doubleclicking Sweethome3D run software starts but the nothing happens
=> for terminal : cd to SH3D directory then SweetHome3D results in command not found

java version :
openjdk version "11.0.9" 2020-10-20
OpenJDK Runtime Environment (build 11.0.9+11-Ubuntu-0ubuntu1.20.04)
OpenJDK 64-Bit Server VM (build 11.0.9+11-Ubuntu-0ubuntu1.20.04, mixed mode, sharing)