Improve performance Frame::getSpatialAcceleration() by removing redundant computation
Improve performance Frame::getSpatialAcceleration() by removing redundant computation

axeisghost/DART6motionBlur,dartsim/dart,axeisghost/DART6motionBlur,axeisghost/DART6motionBlur,dartsim/dart,dartsim/dart,dartsim/dart,dartsim/dart