Houdini Wisp Generator HDA

Over the Winter of 2022, I was reading through papers in preparation to write my own Thesis when I stumbled across this paper from Yujie Shu on Wisps. I remembered some of the lectures I had from Dr. Tessendorf, and decided that I wanted to work to create a tool that would let me use Fractal Flames / Wisps in Houdini as practice for doing them with code in a later class. I turned my practice into HDA’s for creating Fractal Flames / Wisps that I could use for later projects, and have posted a few examples and a breakdown here!

FSPN Wisps

Fractal Sum Perlin Noise Wisps have been used to create the illusion of whitewater along with other magical effects. They are created by displacing several hundred or thousand points with FSPN and animating it over time in order to make it move.

I created a setup for creating either individual wisps or several wisps from a POPnet as well as converting those resulting points to volumes for rendering purposes. I have also included functionality that will allow me to control the wisps over their lifetimes in order to fine tune my effects.

The biggest reason that I decided to experiment with wisps was due to their extremely fast processing time and from them not being dependent on the previous frame. On the relatively slow computers from Clemson’s campus, it has been great to be able to change an entire volume without needing to have the entire project re-sim.

Below are some of the settings that I have on my controllers for my wisp generation. I am still experimenting with wisps and adding different parameters, so the final release may be different than the tool pictured below. These different parameters seemed to be the most relevant towards getting my project done, and all of the ramps are based around the age / life of the particles that are being used to source the wisps.

Practical Application with Whitewater

Here is an example that I rendered out of using wisps to imitate a waterfall. This would be used in conjunction with a water simulation, but for the time being I have rendered this as a test of what I can do with wisps. I hope to use them for whitewater in the future, and I have been enjoying the control that they offer.