entity path for non timed data

CesiumJS
1

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

setInterval(function(){doSend();},500);
    function doSend(){
        tick++;
        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 {
            path:{
            show:true,
            width:10,
            material:
                new Cesium.ColorMaterialProperty ({
                    color:{
                        rgba:[255,0,255,255]
                    }
                }),
            resolution:120,
            leadTime:60,
            trailTime:60
        }
}

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

thanks

2

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