Abstract: Systems for generating custom motion trajectories for robot animation are disclosed. One system includes a robot configured to maintain a current emotion state for the robot and a mapping between emotion state values and respective sets of custom motion parameters, in which the custom motion parameters control how procedural animations are performed by the robot, to receive one or more animation parameters of a procedural animation to be performed by the robot, to obtain a value of the current emotion state for the robot, to obtain one or more custom motion parameters to which the current emotion state is mapped, to compute a custom motion trajectory from the one or more animation parameters of the procedural animation and the obtained one or more custom motion parameters to which the current emotion state for the robot is mapped; and to perform the procedural animation according to the computed custom motion trajectory.