The
Air attributes can be found in the bifrostAeroProperties attributes.
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Density
- The mass per volume of the surrounding medium in kg/m3. The default value of 1.225 corresponds to the approximate density of air at sea level at about room temperature.
-
Temperature
- The temperature of the surrounding medium in degrees Celsius (°C). The default value of 20 corresponds to 68 degrees Fahrenheit, or about room temperature.
-
Smoke Threshold
- The threshold of the smoke channel below which particles get culled. During a simulation, the gas diffuses across space, so that there may be large regions that have non-zero amounts of gas, but still not enough gas to see. The threshold prevents these regions from being included in the computation, thereby decreasing simulation time and memory requirements. Setting this value too low may cause unnecessary calculations across a large volume. On the other hand, setting this value too high may produce very little gas, or cause "popping" and other artifacts when visible particles are killed particularly if
Density
Scale is also set to a high value in the bifrostAeroMaterial shader.
- Smoke Dissipation
- Controls the dissipation of the smoke channel to reproduce effects like evaporation. At a value of 0.0, there is no dissipation.
The smoke channel is used to cull particles when its value falls below the
Smoke Threshold. It is also used by the bifrostAeroMaterial shader to control opacity by default.
- Randomize Velocity
- Controls the amount of randomness added to the velocities. This can be used to mimic turbulence and add detail to break up overly smooth flows.
- Wind Magnitude
- Controls how strongly the gas tends toward the wind direction and speed. Setting this value too high may dampen the gas if the velocity of the simulation is faster than the wind.
- Wind X,
Wind Y
- The speed of the wind in the corresponding world axes. This controls both the direction and the speed of the wind.