Thursday, 16 April 2015

Dry Ice Simulation : Maya Fluids

Dry Ice is a very popular cinematic effect used in Commercials and Films. Dry ice in its simplest form is called as Solid form of Carbon dioxide which is pressurized and given with a form of Cube. The Dry Ice is used as a refrigerant as its extreme cold quality of having temperature upto -78oC has made this element unique.

The Dry Ice is also used for fun and creating astonishing effects. We can pour some cubes of Dry ice into a bowl and can add few quantity of hot water inside it, the moment water is allowed to react with Dry ice a cold smoke is released and attracts people eyes. This unique smoke is so different than other smokes because its stays low as being cold in nature. Some people also add chemical flavor to produce interesting color effects.

Now the question comes, How to create this stunning impact with Visual Effects. We are using Maya to create this impact, the main lead is Fluids. We need to have an emitter which could be spherical and scaled off to y-axis a little bit.

Add density of 10 to 6 in density emitter and use turbulence of 10 to 12 in Fluids Emitter.
Now, we are required to have fluid container make it 10, 10, 10 in size from all axis. In simulation settings use following attributes.

1. Viscosity of about .020, Damp .010, High Detail Solve to ---ALL,Simulation Rate scale—1.

2. Use Density and Velocity Grids only.

3. Give -10 Buoyancy and .25 Dissipation with .25 Noises and 15 Gradient Force. Most important to use Density pressure 3 and Density Pressure Threshold of 1.

4. Velocity use swirl of 6 only.

5. Under color use any color u wish to use.

6. Opacity Graph is a bit tricky use carefully, create three points on graph and assume them in linear

 Now, the first point is raised with 5 values from y axis followed by 25 value of second point and 60 to the last point. Don’t stretch the third point to highest value of graph in y axis...

Use in built fluid light system to avoid heavy rendering of Fluids and opt for Mental Ray.

Use resolution of 100 and took a Play blast for 75 Frames..............Enjoy and Urs Dry Ice is done.