I did some research and here are some of the few 3d Engines that I consider downloading.
SIO2, Unity3d, ShiVa 3d.
Can anyone advise me which of these 3 are beginner friendly?
I tried Unity 3d and went through their beginner tutorials and videos, and I felt that maybe there are other engines that are easier to pick-up.
My plan of using this 3d engine is to create an app that can create dungeon based on the user's input.
eg: if I want a 10 tile dungeon, the app will create a 10 tile dungeon.
If you're targeting mobile platform i would suggest just pick emulator and start write some code.
By writing from scratch you get best optimization. Personally i suggest to write your own code . Should not be so hard.