Add Drag Force Node apply drag force to the Simulation Data. Field velocity is slow down by this node.

Input / Simulation Data:
Input simulation data for Add Drag Force. You must connect this input for work.

Input / mask Grid:
Input field grid data for masking. The mask makes gradient effect between min Mask Falloff and max Mask Falloff.
Input SDF Grid will be convert to Fog grid(surface = 0.0 / deepest = 1.0) and use that value for the gradient and effect.

Output / Simulation Data:
output result simulation data.

Drag:
Defines intensity of the drag force.

Invert Mask
Inverts the mask.

min Mask Falloff:
Start (or End) Falloff and use this value if the mask voxel value is more than it.

max Mask Falloff:
End (or Start) Falloff and use this value if the mask voxel value is less than it.