缓慢启动 meaning in English

hanging start
slow start
slowstart

It needs the designer to set some key frames manually , and at every key frame , the designer should also set the object ' s motion property according to his experience or scientific compute results . then computer gives some interpolatory values and realizes the whole movie . though a lot of commercial soft wares have some intelligence and can set the interpolatory values to achieve users " requirement in some degree , these soft wares ca n ' t satisfy users " requirement well , especially when users want to express their interactive desire
虽然目前优秀的商业应用软件已经具备了一定的智能，对这些关键帧之间的插值算法进行某些设定，如使物体运动的速度在两个关键帧之间呈抛物线分布，达到缓慢启动和停止的效果，使之具备一定的真实感，然而这些工作仍然远远不够，尤其是用户想在运动过程中想表达交互愿望时，这些软件的表现更是难以满足。