For the last few years I have been working on and off on what is hopefully a WYSIWYG 3D level editor!
To use it you must have XNA Game Studio (http://create.msdn.com/en-US) Installed!
The current state is pretty stable, it's current supported features are:
- Working Scale, Rotate and Translate Gizmo.
- Common selection methods (Drag box, Shift Click, Ctrl+A etc.)
- Saving / Loading.
- Undo / Redo.
- Organise elements of the scene into groups.
- Import Models on the fly.
- Imported models automatically added to the ContentProject.
- Support for loading and saving height maps.
- Tools to raise, lower, smooth, create ramps and paint terrain.
- Colour map generation based on normals and terrain height (Incomplete).
- Alpha mapped models such as trees.
For this reason I thought it might be useful to you the community; hopefully it will help you speed up creating your own games so you don't have to worry about making tools from scratch!
Terrain support was only added very recently to the editor so may not fully work as expected! If you find a bug, let me know!
P.S Use the save button on the terrain tab to save the terrain, saving the scene doesn't save the terrain yet!
If you have any questions just ask and i'll try and help as best I can.
I hope you enjoy using it!