调用高亮的关键代码：     
 let graphictruck = new mars3d.graphic.ModelEntity({
        position: [116.327881, 31.018378, 5000],
        style: {
          url: '//data.mars3d.cn/gltf/mars/qiche.gltf',
          heading: 90,
          scale: 0.9,
          minimumPixelSize: 300,
        },
        clampToGround: true
      })

      graphicLayer.addGraphic(graphictruck);


      $("#btnSelPoint").click(function () {
        graphictruck.openHighlight({
          silhouette: true,
          silhouetteColor: "#00ffff",
          silhouetteSize: 8,
        })
      });

      $("#btnUnSelPoint").click(function () {
        graphictruck.closeHighlight()
      });