Page History

...

Box – Cells are displayed as cubes. There is no blending between neighbor cells. The fastest mode.
Linear – Blends between neighbor cells linearly to smooth out the effect's appearance. Sometimes this option might result in a visible grid-like effect. This type is roughly 20-30% faster than the Spherical type.
Spherical – Uses special weight-based sampling for the smoothest-looking fluid. With increasing resolution, the visual advantage over the Linear method becomes less noticeable. 

Surface channel – Controls which physical channel represents the isosurface. By default it is the liquid channel, but smoke or other channels can be rendered as isosurface geometry.

Texture
Temperature
Smoke
Speed
Fuel

– Specifies the channel that defines the surface of the fluid. It is used for solid rendering and displacement.

Texture - the values of a custom texture will define the liquid surface.
Liquid/Temperature - the Liquid/Temperature channel will define the liquid surface. Temperature is typically in the range 0-1 for Liquid simulations and 600-2000 for Fire / Smoke simulations.
Smoke - the Smoke channel will define the liquid surface. Smoke is typically in the range of 0-1 for Fire / Smoke simulations.
Speed - the Speed channel will define the liquid surface. Speed channel output has to be enabled for this to work. Speed is calculated as the length of the velocity vector for each voxel.  
Fuel - the Fuel channel will define the liquid surface. Fuel channel output has to be enabled for this to work. 

Isosurface level – Allows you to specify a treshold value for the generation of the liquid surface. Grid cells below this value will be ignored. By default, the Isosurface Level is set to 0.5 and should only be modified if there is flickering in the generated geometry. Isosurface Level is used only in Isosurface and Mesh modesIsosurface level – The threshold level that determines which cells are considered full/empty. Only cells with values above this level will actually be rendered. The higher the value, the smaller the volume of the isosurface geometry, and vice versa. With higher values, fewer cells will have enough liquid to be visible. Note that for OpenVDB level sets, this should be set to 0.0 to get an accurate result.

Invert volume – By default, the values above the surface level are considered internal. When enabled, this option swaps the inside and outside. Note that this should be enabled for OpenVDB level sets.

...