We've always been able to export terrain meshes, but with Bryce 6.1 you can now export a boolean conversion, that is if you take a positive and a negative and boolean them, you will get a 'convert' icon [c] on the icon column. You can then export this as an obj, dxf, etc.......
Hope this helps.

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All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...