Maybe the work I'm doing could help you whith the Walkmesh/Texture-Overlay function we talked about..
What I actually did was:
-Open the fire Cavern entrance file
-Copy each f*kin* vertices coordinates of each point of the walkmesh one by one and placing them in 3Ds Max
-Rebuild the walkmesh Plane
-Created a camera and alligned it to the camera position showed by the editor (but seems wrong or I didn't actually understood something..)
-Created another camera and now I'm tryng to use a custom texture (positioned in front of the camera) and try to get the right position and angle for the camera manually..
here's a screen that could help to understand my method
If anyone could tell me how to export the walkmesh coordinates into a single text file (or better how to export the walkmesh to a 3D file format) I'd be very thankful to him/her..