ForeArmRoll

The ForeArmRoll object represents roll nulls along the length of a bone. When used as deformers on an envelope they evenly distribute twist along the length of a bone giving a more natural skin deformation.

The start and end rotations are determined differently for a forearm roll and bicep roll (see BicepRoll). In forearm roll, the starting rotation is the forearm's rotation minus any spin, calculated using the bicep's rotation. The end rotation is the next bone's rotation (wrist) with spin. Roll division rotations are then interpolated between the start and end. In the case of bicep roll the bicep bone is used for both start and end rotations. The start rotation is the bone's rotation minus spin, the end rotation is its rotation with spin.