Ha! I am working on a very similar project at the moment. City buildings of in the distance and to the horizon is not a big issue since you can't see clearly how they relate to each other and any road infrastructure you may have. Intersecting buildings are likely to happen but at that distance will not be a visual problem.
I would load each building object separately and have four population nodes with their rotation limited to min 0 max 0, min 90 max 90, min 180 max 180 and min 270 max 270 respectively.
Also look at the "
Spacing variation in a,b", setting this to 0, 0 will create a perfect grid.
You will need to calculate your "
Object spacing a,b" to allow sufficient gaps for other populations and the more populations you have the trickier this will become.
Of course you can create a custom mask (
Use density shader) for each population but realise that this will calculate the distribution masking based on the objects centre and NOT its bounding box so make allowances for that.
As regards the illuminated windows as long as the buildings are UV mapped all you will need to do is make an appropriate image and plug it into the luminosity channel of the default shader.
Hope this helps and looking forward to seeing your results (if you can post them)