entity path for non timed data

Hello I am starting with Cesium and trying to put an entity with initial position and after modifying the position ,

    function doSend(){
        var xp = tick *0.5;
        var yp= tick * 1000;
        var zp = tick * 100;
        entity.position = Cesium.Cartesian3.fromDegrees(xp+lon,lat,z);

then non timing as in CZML stream .
The question is , why I can't see the path that I configured as :

...entity {
                new Cesium.ColorMaterialProperty ({

Maybe is not possible to see the path if no timing reference are in place ?


you need to use a SampledPositionProperty, I also found in my application I needed to set availability but I may have done something wrong