I've used VistaPro landscapes in LightWave. It took several steps but the LightWave render was good. This is what I did (from memory).
I generated the landscape file in VistaPro, which if I remember correctly, can save in TurboSilver format. This is the old Imagine format.
Anyway, I then used the MagicLink mesh converter to get the .lwo file. The MagicLink tool was included with C4D on CUCD27 or with the original C4D package.
If this is of any interest, I'll dig a bit deeper into my hard drive.
Cheers,
JaX