可以参考这个示例
https://layaair.ldc.layabox.com/demo2/?language=ch&category=3d&group=Camera&name=D3SpaceToD2Space
private animate(): void {
this._position.x = Math.sin(this.scaleDelta += 0.01);
this.layaMonkey3D.transform.position = this._position;
this.layaMonkey3D.transform.scale = this.scale;
//转换坐标
this.camera.viewport.project(this.layaMonkey3D.transform.position, this.camera.projectionViewMatrix, this._outPos);
//赋值给2D
this.layaMonkey2D.pos(this._outPos.x / Laya.stage.clientScaleX, this._outPos.y / Laya.stage.clientScaleY);
}