Although not that common, some 3D models or shapes can be saved in KMZ format (compressed Keyhole markup language). Some 3D modeling programs supports import of these files and can convert them to other 3D formats, including .xgl (XGL 3D). This can for example be done using AccuTrans 3D, but it is likely other programs may also perform this conversion.
Convert Compressed Keyhole Markup Language (Google Earth) data to XGL 3D CAD model.
We found one software available in the database for this conversion.
Microsoft Windows software - convert kmz to xgl on Windows
A CAD 3D geometry translation software
Convert from kmz 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.