These settings affect the interpolations in movie making. See also mview, which has arguments power, bias, simple, hand and linear.
motion_bias (float, default: -1.0) with bias>1, the motion will pause for some frames around the keyframe
motion_hand (int, default: 1) determins the rotation direction for full 180° turns
motion_linear (float, default: 0.0)
motion_power (float, default: 0.0) With power<1 the motion will slow down at keyframes, with power=1 it will not change the speed.
motion_simple (int, default: 0)