It seems Live Interior 3D home and interior design software supports export to PDF and thus can export saved designs (*.li3d) as pdf documents. This most likely just creates 2D image of the design and save it on a page of the document.
Convert BeLight Live Interior 3D design file to Adobe Portable document format.
We found one software available in the database for this conversion.
Apple macOS / Mac OS X software - convert li3d to pdf on OS X
A Home and interior design application for Mac
Convert from li3d file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.