Attached Link: http://www.smartconverter.com/

One format that Carrara uses for this output is Photoshop .psd files using the G-buffer settings. I really don't know whether it's possible to convert from .psd to .rpf (one coverter I looked at would read but not write the formats) but you might try the software at the link. Otherwise, cross-grade to 3DSMAX? ;-)