[]龙骨动画残影

请问，为什么我的龙骨动画导入laya后，在动画片段转换之间(如第0个到第1个）会有残影？动画资源是直接用龙骨的官方DEMO转的。部分代码片段如下：
 private _onAnimationCreated(ani)
    {
        console.log("ani created:" + ani);
        this._hero = ani;
        this.addChild(this._hero);
        this._hero.pos(300, 400);
        this._hero.scale(0.3, 0.3);
        this._hero.on(Laya.Event.STOPPED, this, this._onPlayed);
        this._play();
        

        
    }

    private _play()
    {
        if (this._curAction >= this._hero.getAnimNum())
        {
            this._curAction = 0;
        }

                    
        this._hero.play(this._curAction, false);
        ++this._curAction;
        
    }

    private _onPlayed()
    {
        console.log("played");
        
        this._play();
    }