I am working on projects involving imaginary cities. These would often be on non-flat surfaces (like going up a mountain).
So what I currently do is create a bunch of instances of simple building geometry, either manually distributed or with the "scatter" compound object. When I want a "line" of buildings, such as along a street, I use a plugin called PropLine.
Once I have them where I want in top view, I then use the "scripted glue" plugin to drop them down to the mountain geometry.
This becomes less tenable and rather tedious when dealing with very large/complex/distant scenes, however. It can be difficult to tell how exactly they are going to fall onto the mountain with my current approach, and performance can get laggy very quickly with the likes of Propline.
What I really want to do is "spray paint" my buildings directly in the viewport, with lots of control over rotation, size variability, clumping-without-overlapping, flipping, and also the option for billboarding. Whatever it takes not to weigh down an already hypercomplex scene. I definitely still want to add groups of plants as well, but getting a "natural forest distribution" is lower on my priority list. I'd rather have options for "irregular grid" patterns that are more common in city maps.
BTW, I have already tried Carbon Scatter for Max awhile back and it was terrible, causing constant crashes and not appearing to have many options (although hard to tell just how limited it was due to the crashing). I'm now looking at "MultiScatter" and "Forest Pack Pro." It does seem that with these, I'm paying for all the "natural" forest capabilities, which is less of my priority. I'm also a freelancer just breaking into this space, so funds are limited, but I'll still shell out $$$ if I really have to in order to accomplish this goal.
So if you know of a good plugin/native workflow for this purpose, I'm all ears. I'm in Max 2015, BTW. Thanks!