PolylineGeometry with marterial of PerInstanceColorAppearance does not work

[a873054267]

I want to render the polyline with the marterial of PerInstanceColorAppearance，But it's seem to not take effet with the following code.
I finally made it when I use SimplePolylineGeometry to construct instance.So I want to understand what's the diffrent of PolylineGeometry and SimplePolylineGeometry on this point.

instanceFunction

function getGeometryInstance (lineStringArray) { return new Cesium.GeometryInstance({ geometry : new Cesium.SimplePolylineGeometry({ positions : Cesium.Cartesian3.fromDegreesArrayHeights(lineStringArray), width : this.style.width, dashLength : 60, vertexFormat : Cesium.PolylineColorAppearance.POSITION_ONLY }), attributes : { color :Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.fromRandom({alpha : 0.5})) } }); }

var instances=[]
let arr=[116.2440766312067, 40.07389305730007, 34.855640866749, 116.24395125626549, 40.07382653757002, 34.9963782427669]
instances.push(getGeometryInstance(arr))
arr=[116.24393223274961, 40.073864289142065, 34.97, 116.24400014887023, 40.07389668017142, 34.870453622917]
instances.push(getGeometryInstance(arr))

addprimitive

var primitive= viewer.scene.primitives.add(new Cesium.Primitive({
geometryInstances : instances,
appearance : new Cesium.PerInstanceColorAppearance({
flat : true,
translucent : false
}),
asynchronous:false,
}))

[hpinkos]

Hi @a873054267, See this example: https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Apps/Sandcastle/gallery/development/Simple%20Polyline.html

Unless you have a reason not to, I would recommend adding polylines using the Entity API https://sandcastle.cesium.com/?src=Polyline.html&label=Geometries

Next time you have a question, please ask on our forum: https://groups.google.com/forum/#!forum/cesium-dev