Greetings!
I just wanted to show here a little something that I use to export scene from 3ds max to CrystalSpace (just a rip-off of original exporter, I just wanted something more dumb-proof and easier), since I'm unable to do anything else for a week. I think it's good enough to be considered as being alpha or beta version that doesn't support terraforming (because I don't use it yet) and many more features, like LOD and others...
I can't remember much
Ok. Now a little information on how to use it:
There's only one requirement (that I can remember): geometry objects should be UV-mapped
Dynavis is used as culler at the moment
For single-sector level just place objects where you want them to be.
Omni-lights are exported as light sources
Primitives that can be used without "Edit Mesh" modifier to be used in CS are sphere and box.
Other objects (at least editable meshes) WITHOUT CUSTOM PROPERTIES will be considered as genMesh objects (and factories also will be automatically created)
If you want several objects to share one factory, just create Instances then. Instanced objects will have one factory (randomly chosen).
Don't use different colours for one of the instances, colours will be set in factory only anyway (todo, I hope to add this feature soon)
For multiple-sector level just use dummies with "SECTOR" custom property. Their names will be used to name sectors, and their children objects will be exported...
Materials: 3 maps can be used: diffuse, bumpmap and displacement map (I use it to export normal maps X) )
Transparency depends on "Opacity" in Blinn's basic parameters: 100% - nothing, 50% - binary, anything else - smooth.
Something similar for "Self-Illumination": If you'll choose white colour (255, 255, 255) then "fullbright" shader will be used.
If no map is assigned then color values will be used
If no material is assigned then object's wireColor will be used
Scene custom properties: Default scale is "1"
Default room name is "room"
These values will be written to scene custom properties on level export (at least if it was successfull)
To change roomname you need to do it manually from custom properties
Scale parameter is being overwritten each time you export a level, so just change it in exporter.
Sky: (by adding custom property "SKY" to an object)
Don't use Instances for this type of objects since their position against player is set in the factory and cannot be changed.
Note: As partially said above position of these objects is set against the player's starting position.
Portals: Only quad portals with custom property "PORTAL = TargetSector" at the moment...
P.S. If this exporter will be at least somewhat useful, I'll add info here. Just ask questions then...
Exporter should run on 3ds max versions from 5.1 to 9 I think. And I'm not responsible for the results of its "work"

Attached file is a ZIP file actually