先上unity和laya效果的对比图

import ModelViewer from "./ModelViewer";
import Scene = Laya.Scene;
export default class Game3D extends Scene {
	constructor() {
		super();
		//初始化引擎
		Laya3D.init(0, 0);
		var scene_360 = Laya.loader.getRes("LayaScene_PUCHENG3D/Conventional/PUCHENG3D.ls") as Laya.Scene3D;
		Laya.stage.addChildAt(scene_360, 0);
		var camera = (scene_360 as Laya.Node).getChildByName('Main Camera') as Laya.Camera;
		// var camera = new Laya.Camera(0, 0.1, 100);
		// scene_360.addChild(camera);
		camera.transform.rotationEuler = new Laya.Vector3(-32, -75, 0);
		camera.transform.position = new Laya.Vector3(-8.2, 5.3, 2.2);
		var modelViewer = camera.addComponent(ModelViewer);
		modelViewer.AroundPos = Laya.Vector3._ZERO;
		
		var directionLight = (scene_360 as Laya.Node).getChildByName('Directional light') as Laya.DirectionLight;
		//灯光开启阴影
		directionLight.shadow = true;
		//可见阴影距离
		directionLight.shadowDistance = 20;
		directionLight.shadowResolution = 2048;
		var receiveShadowgroup = (scene_360 as Laya.Node).getChildByName('PuCheng').getChildByName('receiveShadow');
		var castShadowgroup = (scene_360 as Laya.Node).getChildByName('PuCheng').getChildByName('castShadow');
		receiveShadowgroup._children.forEach(_model => {
			//(_model as Laya.MeshSprite3D).meshRenderer.castShadow = true;
			(_model as Laya.MeshSprite3D).meshRenderer.receiveShadow = true;
		});
		castShadowgroup._children.forEach(_model => {
			(_model as Laya.MeshSprite3D).meshRenderer.castShadow = true;
			//(_model as Laya.MeshSprite3D).meshRenderer.receiveShadow = true;
		});
	}
}

以上代码是对灯光阴影的设置，和模型网格光照信息设置。（好坑，unity设置的接收阴影产生阴影都不管用，得重新代码撸！！）

模型用的材质是'PBR(Standard)'，求大佬和技术人员解惑，看看我这是啥地方出了问题。