I need to make grid based levels with 3d models for a dungeon crawler ( as a recent example Legend of Grimrock), but i need to have several layers and place entities with properties and position, angle, etc. I was considering Tiled, using layers as height for each level, but it's very hard to work with and visualize. What can i use for this pourpose? The output format needs to be json, xml, or something i can use on my engine. Ideally i'd want something like Tiled with a 3d visualization/edit mode and support for loading models or at least some visual representation of them.
You can try TuDee:
I have used it successfully for 3D tile-games. It exports XML, so it is easy to read into whatever game engine you are using. It supports multiple maps (useful for different levels), as well as layers, entities, custom variables, and many other features.
Here is some more info: