You can also use UV mapping in wings3D and save the model and import it in to Bryce.

Wings3D is excellent and completely free.

David Brinnen has a very good tutorial on how to do it here:

https://www.youtube.com/watch?v=Qi_QdTlRY6E&list=UUldbpx-WrHFHUD-w3IaIKkw

This was my first attempt following the tutorial.

http://www.renderosity.com/mod/gallery/index.php?image_id=2523372&user_id=472626&np&np