private void DoTranslation(Vector3 axis) { if (rigidBodyEnabled) { rigidBody.AddRelativeForce(deltaV * axis, ForceMode.VelocityChange); } else { // for a massless (wrt e.g. Earth) ship, applyimpulse will just do a change in velocity ge.ApplyImpulse(nbody, GravityScaler.ScaleVelSceneToPhys(deltaV * axis)); } }