Some more pictures. I figured out how to correctly render separate geometry in the file.
Fallengate Entrance

Fallengate Marketplace

Freeport North wall

Commonlands Terrain

Really good job Andrew, I have a little question, there is a big CPU charge when you load hit or render it ?
And this is possible to translate that in a geodata engine ?

It's a 3D collision mesh so you will be able to load it up into a physics engine.
There's some more data in here such as boundary information and leaf data. I assume they're used to find which part of the mesh the player is interacting with for optimisation, but it's not a big deal right now.
Loading the hit file takes less then a second.

Small update. I figured out 90% of the format now, although in some files there is one polygon that seems to not want to render, don't know why.
Bridge in commonlands

Neriak Tunnel

Commonlands Terrain

The pic above shows the village in the middle of commonlands. The black hole you can see in the pic is where the well is.
Problem now is that there are multiple hit files for a zone and I have to figure out how the client puts them together.

Andrew wrote: Problem now is that there are multiple hit files for a zone and I have to figure out how the client puts them together.

In the "spawn info" structure you have a field called a grid ID. Any chance these .hit files happen to have some of these in there?

Check out the first page in this thread for an example of all the file data..
I don't think grid id is in there.. I think something else calls the individual hit files, but please take alook at the data maybe it'll make sense to you.