(Not available on fluid texture.) Increase this value to increase the number of samples per ray used in the render, thereby increasing the shading quality of the render.
By mapping a texture to this attribute, you could define exactly which regions of a fluid got the highest shading quality (although the slowdown due to texturing might negate any benefits).
(Not available on fluid texture.) Defines the maximum contrast in the effective transparency of a volume span allowed by the Adaptive subdivisions sample method. When the contrast between two spans is greater than this value Maya subdivides the span. The contrast is defined as the effective difference in accumulated transparency from the viewpoint.
If this value is high, then the sampling will look like Uniform sampling.
If the Contrast Tolerance is low then the quality improves and the render time increases, although you will not require as many samples as uniform sampling for a given render quality.
The Quality setting should be just high enough that you do not miss dense regions altogether (this creates artifacts like dotty fringes around clouds).
(Not available on fluid texture.) Controls how the fluid is sampled during rendering. Jitter avoids banding artifacts, but adds noise to the final image unless the Quality is set high.
Select the interpolation algorithm to use when retrieving values from fractional points within a fluid voxel when shading a ray. Sharply contrasting densities may show grid artifacts (like a mesh with no normal smoothing) with Linear interpolation. Smooth interpolation renders slower, but eliminates these problems.