Instead of keeping track of one global time value, use multiple bounded low-frequency oscillators. This will keep working for an unlimited amount of time.

This was causing a compiler warning

https://code.google.com/p/nanoflann/

From nanoflann-1.1.7

Tested on MIPS OpenWRT router

This gives us opportunities to improve performance, since particles have a finite distance over which they
provide a contribution to the scene. This also includes kernel function and its derivative for use by subclasses.