I spent some time yesterday and today making a tool for Unity that uses physic simulations to place objects in a scene by letting them fall "naturally" so your placement of them is less tedious and more accurate to the worlds curvature and feel.
You can find the tool, MIT licensed, here on my github. I just released a version 3 this evening that has most of what I want it to do. There are still some things I'm going to consider adding such as smooth simulation so that you can see it happen rather than it skipping to the last frame of the simulation immediately.