Cesium的model初识

学习Cesium的model的基础知识。

#primitve方式加载模型

// Cesium.Transforms.eastNorthUpToFixedFrame去创建了一个以经纬度为原点的enu（east-north-up ）局部坐标系。 
var modelmatrix=Cesium.Transforms.eastNorthUpToFixedFrame(Cesium.Cartesian3.fromDegrees(118,31,1000)); 
var model = viewer.scene.primitives.add(
    Cesium.Model.fromGltf({
        url:"../data/models/CesiumAir/Cesium_Air.glTF",
        modelMatrix:modelmatrix,
　　　　//模型大小系数
        scale:100,
　　　　//裁剪面
        clippingPlanes: clippingplans           
    }));

#模型运动显示

//设置开始时间
var startTime = new Cesium.JulianDate.now();
//加载后activeAnimations.addAll({})
Cesium.when(model.readyPromise).then(function(model){
    model.activeAnimations.addAll({
//the style of thr model movement,thiS MIRRORED_REPEAT style means "moving clockwise and then moving anti-clockwise" 
        loop:Cesium.ModelAnimationLoop.MIRRORED_REPEAT,
        startTime:startTime,
　　　　//stopTime: startTime,stoptime(seconds),create new time (new Cesium.JulianDate())　　　　
        stopTime:Cesium.JulianDate.addSeconds(startTime,10,new Cesium.JulianDate())
    })
});

#clippingPlane

the core  :ax+by+cz=d; a,b,c,d is four parameters

try to understand this by mathmatics

var clippingPlane= new Cesium.ClippingPlane(new Cesium.Cartesian3(0,1,0),0);//(a,b,c),d
var clippingplans = new Cesium.ClippingPlaneCollection({
    planes:[clippingPlane]
    });

#pick the model

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
handler.setInputAction(function(movement){
    var pick = scene.pick(movement.endPosition);
    if (Cesium.defined(pick) && Cesium.defined(pick.node) ) {
        console.log('node: ' + pick.node.name + '. mesh: ' + pick.mesh.name);
    }
},Cesium.ScreenSpaceEventType.MOUSE_MOVE)