AnimationMaterialProperty

Example:

viewer.entities.add({
 name: 'PolylineTrail',
 polyline: {
     positions: Cesium.Cartesian3.fromDegreesArrayHeights([lon, lat, 2500,
         lon + 10, lat, 2500,
         lon + 10, lat + 10, 2500,
     ]),
     width: 15,
     material: new TS.AnimationMaterialProperty({
         // color: Cesium.Color.ORANGE,
         duration: 3000,
         image: "./img/flow.png",
         // repeat:new Cesium.Cartesian2(30,1),
			axisY: true
         })
     }
 });