None

Select None in the Rotation Filter menu if you do not want to apply any rotation filters.

Gimbal Killer

Select the Gimbal Killer option to compensate for gimbal locking effects by adding additional keyframes to your rotation function curves. These additional keyframes compensate for sudden flipping or shaking caused by the interpolation between keyframes during large rotational changes. Gimbal lock is most often encountered when you plot animation onto the skeleton of your model.

Unroll

Select the Unroll option to unroll equivalent Euler rotations, making the curves continuous.