As it looks like we will have classes using the Crysis Sandbox editor to create real-time visualisations this coming session, I was just poking around at the kind of compatibility we might expect with other tools.
There are threads like this one on SketchUcation on boards about the place showing people doing this kind of thing. It all feels very beta-like as the process could use some real refinement. We have 3ds Max, which will help no doubt, but it would be nice to have a fluid way to get from model to 3D real-time... The Crymod site and forums are is the main place for such things though. I like the work some of the folks are doing in using data from things like Google Earth. The levels using the US Geological Survey data are awesome and there is a tute by 4K1R4 showing how he does it.
Enter ZapWizard, he is doing some very cool stuff getting assets from various places into Sandbox 2. In this thread he takes a SketchUp model into XSI then into Sandbox2 (Crysis) as a test. Here are the 3 images showing the steps - very cool. Note also the Collada interaction as well.
[3 images showing ZapWizard bring a Sketchup model into Crysis via Crymod - shrunk]
Next trick from ZapWizard is shown in this thread where he takes some Google Earth data and creates this area in Crysis. It is cool to think that this is a real-time engine we are seeing here - not a render. The first image below is a photo of the place from here. Then we have his grab of the Google Earth data and then his map inside the Crytek Engine. More pics to be found of the map here as well.
[Photo, then Google Earth then Crysis Engine images - all shrunk]
Lastly lets just pop back a little to ZapWizard's version of the Castaway Island in the Crysis engine as well. I dont have enough time in the day to play with all these goodies at this second, but I cant wait to get into it - soon soon soon.