Frame Offset

This offset is added to the current frame number to determine the frame used for rendering. You can use this to create instances of the container that render with a different frame offset each.

Frame Step

By default the render sequence will be the same as the simulation sequence. If you want to render a simulation in backward order, set this value to -1 and the Frame Offset to the end of the frame range. You can also skip frames by using values larger than 1 (or smaller than -1). Using a values of 0 allows you to freeze a fluid frame while animating the rest of the scene.

Step Size

Specifies the step size as a percentage of a voxel that is used to sample the fluid container. Large values make renders faster but can introduce noise. Smaller values reduce noise but need more time.

You should reduce this value only if you see noise artifacts in your renders to avoid increasing the render times unnecessarily.

Shadow Step Size

Shadow rays are usually more robust wrt. noise artifacts. Setting a higher step size for these rays allows you to save render time. This is particularly effective for lit smoke renders.


Specifies the way values are interpolated from the simulation grids.

Fast can be somewhat blurry and have banding artifacts. Smooth is the blurriest but avoids banding completely. Sharp avoids blurriness but can have banding artifacts.

Note that you can always reduce or even remove blurriness by using steep Mapping curves in the shader settings, even when using Smooth interpolation. Also note that the illumination method (see below) can be the reason for banding as well.

Use Distance/Opacity Mapping

Enable the mapping of distance from camera to fluid opacity. See below for details.

Distance/Opacity Mapping

Maps the distance from the camera to an opacity for fluid rendering. This can be used when flying the camera through a cloud. Voxels that are very close to the camera may occlude too much of the cloud or they may simply be too big and look blobby. You can fade away their opacity using this mapping.