I need to develop an interior designing software :)

Much like a virtual room designing software. 

There will be pre-designed 3D objects and they can dragged on to the room. You can change the room size etc... Much like a conventional home designing software :) After the room is designed i should be able to to make the user walk through it...

I know that is a lot of requirements...

But are there any open source IDE's/API's/Engines that can i use to achieve similar results?