Tornado – FX

Task: sim and render of the elements tornado, debris and rain.
Software : Houdini 14
Technique : I’ve used a point distribution animated procedurally to generate velocity and density source fields to drive a low res smoke simulation. In order to maintain the simulation art-directable , at every time step I’ve replaced 95% of the simulated velocity with the source velocity. The resulting low res sim is fast (~1 fps). All the details of the Tornado have been added at render time using a volume procedural shader, which allowed me to advect the original low-res density along vector noise fields mixed with the velocity field itself.
Debris , Debris Skirt and Rain are particle simulations.