This is a final render of my thesis 'Art Directable Tornadoes'. Curves were used to animate the shape. Each of the elements, funnel, debris, dust and cloud were simulated using particle systems (POPs) and fluids (DOPs). Particles are acted upon by vortex and directional forces within Metaball force fields. Each of the particles were used as a source for smoke. The basic idea is to drive fluids using particles. Fracturing was done using voronoi fracture asset and attaching fractured pieces to particles, which are influenced by particle forces.
Rendering was achieved using Houdini's Mantra renderer and billowy smoke shader was used to shade the fluids.