如何以3D模型的倍数打开（显示）深度阴影？

Question

我尝试在模型的深度部分显示阴影。我已经尝试将代码隐藏起来以显示阴影吗？

        var light = SCNLight()
        var lightNode = SCNNode()
        light.castsShadow = true
        light.automaticallyAdjustsShadowProjection = true
        light.maximumShadowDistance = 40.0
        light.orthographicScale = 1
        light.type = .directional
        light.shadowMapSize = CGSize(width: 2048, height: 2048)
        light.shadowMode = .forward
        light.shadowSampleCount = 128
        light.shadowRadius = 3
        light.shadowBias  = 32
        light.zNear=1;
        light.zFar=1000;
        light.shadowColor = UIColor.black.withAlphaComponent(1)
        lightNode.light = light
        //lightNodeb2.position = SCNVector3(x: -1, y: 10, z: 1)
        lightNodeb2.rotation = SCNVector4Make(2, 0, 0, -Float.pi / 3)
        self.sceneView.scene.rootNode.addChildNode(lightNode)

我已附上当前结果和预期结果。

当前结果

预期结果