Hi,
Now you can create, edit and customize 3D digital content within Unity Game Engine , everything is done on top of the engine!
GameDraw is a new way of facilitating the assets creation process to Indies and a new appealing and easy way for professionals to edit create and optimize models , it can be used to do level designs in Unity and can be also used to complement the work flow of 3rd party modeling tools such as 3Ds Max and Blender ...
You can find tutorials and Showcase videos here
You can find the free version here
Cheers