Box#3
Box#3 Display Only Nth Particles
Quick Box#3 setup to only display every Nth particle in the viewport (or render, or viewport/render).
You filter out every nth particle, so for instance if you want to display every 10th particle, take your birth index and you nth integer of 10 pipe them to a division remainder function set an integer condition to equal 0, pipe that to the Output Visibility Viewport filter boolean. Pipe a Scalar Boolean False to the the Input of the Output Visibility. Now if a particle registers false it filtered out and will not be shown in the viewport. Propz go to Oatz (Khye Kading) for re-educating me about Division Remainders years ago 
Hope you find it handy 
Burning Paper
Been a while, here is something…
All particles rendered in Krakatoa and colored via the new KCM (Krakatoa Channel Modifier), just a couple million with the exception of the ground plane. Mostly about flame structure and scale study but thought i’d post it.
The paper is over a million particles image mapped in pflow. The burn is controlled by a animated gradient ramp and a box#3 test. The box#3 data test samples the color of the gradient ramp object, when true (the burn line) it assigns an integer value to the particle and passes it to a new event. This integer value is then acquired by a KCM and colored when the particle data is brought back into a PRT Loader.
The fire is generated in two different passes. It consist of approx 2.25 million particles (a little overkill I might add for the amount of burn happening). The first pass, the base flames, are generated via a spawn the works with the burn line as described above. These particles are simulated then fed back through pflow to generate the second fire pass, the long tendrils. Both of these simulations are then individually saved back to separate Krakatoa PRTs. The particles data is then reloaded using a PRT loader and colored via KCM using both age+lifespan and temperature+gradient ramp.
The six passes were comped in fusion. The background, Paper & debris particle passes, the shadows, and the two fire passes. Some post blur to soften the fire particles, that’s it though.
I hope to get some more time to revisit it, I have a few other ideas I would like to implement.
Random Particle Color
A small box#3 data preset to randomly change your particle color at random times
More Info HERE
Particle Flow – particle flow R&D some new some old
8.0 MB QT
Ground Vortex. A test using a vortex space warp along with a spherical wind, gravity and a few deflectors.
July 6, 2008
Built a new (my first really) Box#3 operator called “Simple Vortex”. It can be used to simulate a particle vortex in particle flow. You can download the operator and watch a 20 second clip that shows what it does. More…
June 23, 2008
Particle Flow arrows 2.3 MB Quicktime
