Goodday schemers,

I've made an extension to octrees, called a 27-tree.
Paper is here :
http://soft.vub.ac.be/~jceuppen/papers/paper27tree.ps

Python code with ultima 8 game is here:
http://soft.vub.ac.be/~jceuppen/python/koboldsquest-2.1.tar.gz

Finally a scheme implementation which can be used with my former framebuffer code, to make a 3D engine, is here:
http://soft.vub.ac.be/~jceuppen/scheme/
(version 0.3 has been tested in guile and s48, fb extension is also in that directory)

Enjoy,
Johan