The rendering preferences pane contains advanced options and parameters for how the data should be played back and rendered.

Playback

Playback rate during continuous playback. A value of 1 will show every frame, 2 will show every other frame, etc. (Default: 1)

Skeleton Alpha

Set the opacity of the skeletons, 3D segments, and local coordinate systems rendered in the 2D views. The slider ranges from 0 (transparent) to 100 (opaque).

Render Smooth IK

If selected, the filtered pose of the skeletons will be rendered. If not selected, the unfiltered pose will be rendered. (Default: Off)