1. Lumion 8.x and newer
Version 7.5 and older: Please see section 2 below.
1.1: Save a copy of the Scene to an .LS file.
Files button -> Save Scene tab:
1.2: Move the .LS file to the other PC and open it.
Files button -> Load Scene tab:
2. Lumion 7.x
Version 8.0 and newer: Please see section 1 above.
2.1: Save a copy of the Scene to an .LS file.
Files button -> Save Scene and Models tab:
2.2: Move the .LS file to the other PC and open it.
Files button -> Load Scene and Models tab: