How to mix the force in with the incoming velocities.

A global scale on the amount of buoyancy to apply. Hot gas expands, causing it to rise due to lowered density. Acceleration due to buoyancy is calculated using the values of the ambient and reference temperatures, as well as the Gravity Acceleration scale.

Temperature corresponding to value of 0 in the temperature field (in Kelvin). This represents the ambient temperature of the environment.

Temperature corresponding to a value of 1 in the temperature field (in Kelvin). The temperature range is used to calculate the strength of the buoyancy force.

Hot gas rises in the buoyancy direction where temperature values are above this ambient temperature, and falls where they are below it. Since newly activated areas have zero temperature, this usually needs to be zero to leave dead-space unaffected. This is useful for simulating cloud formation where gases can rise and fall.

Acceleration due to gravity. Stronger gravity results in a stronger buoyancy force.

The direction in which temperatures hotter than the ambient temperature will be forced.

Mask out the effect using the threshold field. Threshold fields are intended to provide harsh on/off effects, but the range can be used to soften the transition.

The value of the threshold field is mapped from this range to 0-1 and applied as a multiplier on top of Scale. The default 0.01 to 0 range is designed to concentrate the effect on the edges and empty regions of the threshold field, but not inside it. When the threshold field is a Vector VDB, this value represents the length of the given vector field.

Turns on the Threshold Ramp, to change how the threshold field should scale the effect between the minimum and maximum values of Threshold Range.

This ramp controls how the threshold field values are mapped between the minimum and maximum values of Threshold Range.

Mask out the effect using the control field. Control fields are usually used the same way as masks, and represent a smooth engagement of the effect.

The value of the control field is mapped from this range to 0-1 and applied as a multiplier on top of Scale. The default 0 to 1 range is designed to concentrate the effect on regions with higher control field values. When the control field is a Vector VDB, this value represents the length of the given vector field.

Turns on the Control Ramp, to change how the control field should scale the effect between the minimum and maximum values of Control Range.

This ramp controls how the control field values are mapped between the minimum and maximum values of Control Range.

Mask out the effect by the angle between the velocity field values and a direction vector.

The reference vector used to calculate the angle deviation against the velocity field.

The value of the calculated angle is mapped until this angle range to 1-0 and applied as a multiplier on top of Scale. At the default 90 degrees, the effect is strongest where the vectors align, and gradually diminishes to zero as the angle reaches this value.

Turns on the Angle Control Ramp, to change how the angle deviation should scale the effect between the aligned vectors and the given Spread Angle.

This ramp controls how the angle deviation is mapped between the aligned vectors and the given Spread Angle.

Mask out the effect along an axis direction. Rather than requiring the construction of VDBs to represent this, this allows direct specification of the world space range over which the effect is to be scaled.

The reference vector along which the effect will be masked.

The position along the axis mask is mapped from this range to 0-1 and applied as a multiplier on top of Scale.

Turns on the Axis Control Ramp, to change how the position along the axis should scale the effect between the minimum and maximum values of Axis Range.

This ramp controls how the position is mapped between the minimum and maximum values of Axis Range.