Measuring a concentration of points on a surface for Galapagos

Does anybody know how to measure concentration of points on a surface? I have variable arrangements of basically the same number of points on a surface and I would like to know which variation gives me the higher concentration (cluster) of them (per m2, let's say).

I am calculating the reflections of the sun on a curtain wall facade. I need to find out the reflections throughout the year (using the variable sun vector from heliotrope) from a freeform surface facade to see if they focalize on to another facade opposite this building.

I am trying to obtain the moment in time, by running galapagos to the genome of a julian day calendar, when the reflected sun rays that intersect the other facade concentrate the most (sort of like the focal point). Any idea??

I am attaching my definition.

Thanks.