private void initSpeed()
{
if(this.type==TweenAction.MOVE_CURVED || this.type==TweenAction.MOVE_CURVED_LOCAL){
this.time = this._optional.path.distance / this.speed;
}else if(this.type==TweenAction.MOVE_SPLINE || this.type==TweenAction.MOVE_SPLINE_LOCAL){
this.time = this._optional.spline.distance/ this.speed;
}else{
this.time = (this.to - this.from).magnitude / this.speed;
}
}