Patterns in Revit using the Reactor Principle

Last year I posted a video on YouTube, which was a teaser for a presentation that I subsequently did at the Revit Technology Conferences in both Queensland (RTC 2011 Australia) and in California (RTC 2011 USA).  These showed the "Reactor Principle" that used the movement of a single control point to modify the colour of a series of fins on a building facade depending on how far they are from the control point.  I hope to describe at some point in the future a little bit about how that was achieved.  In the meantime, what I did not show was how it is possible to create an almost random pattern using the same technique.

Here is a snapshot of the building facade where the colour change is controlled by a calculation based on a sine wave.  The first image shows the facade with the wavelength pattern set to repeat at 18 metre intervals, which is about two thirds of the building length:

 

If you change the value of just one parameter - the wavelength pattern to repeat at a very small number - say 100mm then you start to lose any visual repitition, so it looks almost random, as below:

It is obviously not totally random, as you can see some repetition in the middle row.  But that could be dealt with by moving the control point out of that row so that it is above or below the building facade.