Cesium Primitive报错：Appearance/Geometry mismatch

Cesium 在用Primitive创建对象时报错：Appearance/Geometry mismatch

An error occurred while rendering.  Rendering has stopped.
DeveloperError: Appearance/Geometry mismatch.  The appearance requires vertex shader attribute input 'color', which was not computed as part of the Geometry.  Use the appearance's vertexFormat property when constructing the geometry.

错误的大致意思就是实体的顶点和材质不匹配，导致渲染出错；

解决方案：

①类似BoxOutlineGeometry这类几何，不能使用光照，需要将appearance中的flat属性设置为true，即关闭光照。

正常代码：

      // 创建boxOutline的几何实例let boxOutlineInstance = new Cesium.GeometryInstance({geometry: boxOutlineGeometry,modelMatrix: Cesium.Matrix4.multiplyByTranslation(Cesium.Transforms.eastNorthUpToFixedFrame(Cesium.Cartesian3.fromDegrees(120, 40)),new Cesium.Cartesian3(0.0, 0.0, 1000.0),new Cesium.Matrix4()),id: "boxOutline",attributes: {color: Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.RED),},});// 创建图元let primitive = new Cesium.Primitive({geometryInstances: boxOutlineInstance,appearance: new Cesium.PerInstanceColorAppearance({flat: true,faceForward: true,translucent: false,closed: false,}),show: true,modelMatrix: Cesium.Matrix4.IDENTITY,vertexCacheOptimize: false,interleave: false,compressVertices: true,releaseGeometryInstances: true,allowPicking: true,cull: true,asynchronous: true,debugShowBoundingVolume: false,shadows: Cesium.ShadowMode.DISABLED,});viewer.scene.primitives.add(primitive);

②绘制Primitive实体时，几何图形的vertexFormat确定它是否可以与其他几何图形组合。两个几何图形不必是相同的类型，但它们需要匹配的顶点格式。我们可以理解成实体的vertexFormat需要与他的appearance定义的材质形式一致。

错误代码：

      let primitive = new Cesium.Primitive({geometryInstances: new Cesium.GeometryInstance({geometry: new Cesium.PolylineGeometry({positions: Cesium.Cartesian3.fromDegreesArray(positions),width: 3.0,vertexFormat: Cesium.PolylineColorAppearance.VERTEX_FORMAT,}),}),appearance: new Cesium.PolylineMaterialAppearance({flat: true,material: Cesium.Material.fromType(Cesium.Material.PolylineDashType, {color: Cesium.Color.CYAN, //线条颜色gapColor: Cesium.Color.TRANSPARENT, //间隔颜色dashLength: 20, //短划线长度}),}),});viewer.scene.primitives.add(primitive);

 正确代码：注意vertexFormat形式更改为PolylineMaterialAppearance

      let primitive = new Cesium.Primitive({geometryInstances: new Cesium.GeometryInstance({geometry: new Cesium.PolylineGeometry({positions: Cesium.Cartesian3.fromDegreesArray(positions),width: 3.0,vertexFormat: Cesium.PolylineMaterialAppearance.VERTEX_FORMAT,}),}),appearance: new Cesium.PolylineMaterialAppearance({material: Cesium.Material.fromType(Cesium.Material.PolylineDashType, {color: Cesium.Color.CYAN, //线条颜色gapColor: Cesium.Color.TRANSPARENT, //间隔颜色dashLength: 20, //短划线长度}),}),});viewer.scene.primitives.add(primitive);