I will effectivement need some camera movement in it.  The camera will pull away from the central point in direct line until it pass in the wall and exist outside in the forest.

Someone suggest me some image projection... How can i do that in vue? Is there any good tutorial about that?

For the shape this is a idea to madel it somehere else...

I made a new test using a new technic. I used a difference boleen function on 2 terrain to obtain the cavern this time. I think the look is better. I still need some better texture... But i think it is better.

http://www.imaginethisproductions.net/p3/grotte_p3_gen2.jpg

Shadu