var instance = new Cesium.GeometryInstance({
geometry : new Cesium.PolygonGeometry({
polygonHierarchy: {
positions: positions,
},
height: 150,
rotation : Cesium.Math.PI_OVER_FOUR,
vertexFormat : Cesium.VertexFormat.POSITION_AND_ST
})
});
scene.primitives.add(new Cesium.Primitive({
geometryInstances : instance,
allowPicking: false,
appearance : new Cesium.EllipsoidSurfaceAppearance({
material : Cesium.Material.fromType('Color',{
color : new Cesium.Color(0.0, 1.0, 0, 0.3)
})
})
}));
我想对这个Primitive加上边框线,请问需要怎么设置参数?