PIXI如何绘制离屏canvas到舞台上

//微信共享canvas
let openDataContext = wx.getOpenDataContext();
            let scanvas = openDataContext.canvas;
            let btexture = new PIXI.BaseTexture(scanvas);
            let sprite = new PIXI.Sprite(new PIXI.Texture(btexture));
            sprite.x = game.stageCenterX;
            sprite.y = game.stageCenterY;
            sprite.anchor.set(0.5);
            sprite.scale.set(1.5);
            this.addChild(sprite);