Having created a RIB archive, simply run
bbgen xxx.riband a bounding box will be printed out. This can then be used directly as part of the RiProcedural command. The current version is 0.2, which has numerous fixes and improvements over the original.
Note that this program should be run on a RIB Archive, and not a comeplete RIB. Unforunatly Angel does not currently support Procedural calls.
Displacement bounds are ignored.
Blobby objects are unsupported.
The current release can be downloaded for freeBSD, Linux, Windows and SGI . As always could any users please register their usage by emailing me.