Dust Devil

Simulation

The simulations for this project can be separated into three parts: the main dust column, the surrounding cloud, and the ambient dust.  The source for the main column and the surrounding cloud was a thin cylinder underneath the ground plane. The velocity volume that was fed into the sim was generated by interpolating between the world up vector and surface tangent vector of a cylindrical surface and then transferring that attribute to points in a volume. Velocity was not modified using micro solvers when simulating the dust cloud to keep it simpler. The density source was sampled from cubes large enough to cover the screen that were turned into volumes. The velocity was injected into the sim using gas wind and gas turbulence micro solvers. 

The debris was created using nParticles in Maya.

Rendering

The project was rendered using Redshift in Maya. The volumes were cached out as VDBs and brought in as seperate Redshift volumes. 

All of the volumes were rendered on separate layers. The ambient dust was rendered with a default dome light. The dust column and the surrounding dust cloud were rendered with a blue dome light and a red directional light for the sun. The sky was turned into an opacity map for a default shader that was applied to a sphere that blocked the sunlight. To get the proper holdout for the surrounding dust cloud, the dust column was rendered with a green tint, which effectively turned it into a matte object when lit with a red and blue light. The alphas for the volumes were rendered separately. 

The ground in the back plate was a grid with 5 different desert ground materials layered on each other. The sky and mountains were matte painted and projected on a card.

The plate and the debris were each rendered on their own layers without any AOVs.