cesium入门（八）

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cesium入门（八）

交互

• 我们可以通过三种方式来通过鼠标和cesium交互
  
  1. scene.pick 通过窗口坐标来取一个对象
  2. scene.drillPick取一个对象列表
  3. Globe.pick 根据光线和地形取一个对象

 // If the mouse is over a point of interest, change the entity billboard scale and color
    var previousPickedEntity;
    var handler = viewer.screenSpaceEventHandler;
    //监听操作类型和处理函数
    handler.setInputAction(function (movement) {
        var pickedPrimitive = viewer.scene.pick(movement.endPosition);
        var pickedEntity = Cesium.defined(pickedPrimitive) ? pickedPrimitive.id : undefined;
        // Unhighlight the previously picked entity
        if (Cesium.defined(previousPickedEntity)) {
            previousPickedEntity.billboard.scale = 1.0;
            previousPickedEntity.billboard.color = Cesium.Color.WHITE;
        }
        // Highlight the currently picked entity
        if (Cesium.defined(pickedEntity) && Cesium.defined(pickedEntity.billboard)) {
            pickedEntity.billboard.scale = 2.0;
            pickedEntity.billboard.color = Cesium.Color.ORANGERED;
            previousPickedEntity = pickedEntity;
        }
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

相机模型

• 两种一种是静态的也是默认的给那在那，第二种是动态的可以自动根据参照物调整

// Create a follow camera by tracking the drone entity
function setViewMode() {
    if (droneModeElement.checked) {
    //自动跟
        viewer.trackedEntity = drone;
    } else {
    //取消第一步先给值underfined第二个飞回默认
        viewer.trackedEntity = undefined;
        viewer.scene.camera.flyTo(homeCameraView);
    }
}
var freeModeElement = document.getElementById('freeMode');
    var droneModeElement = document.getElementById('droneMode');

    // Create a follow camera by tracking the drone entity
    function setViewMode() {
        if (droneModeElement.checked) {
            viewer.trackedEntity = drone;
        } else {
            viewer.trackedEntity = undefined;
            viewer.scene.camera.flyTo(homeCameraView);
        }
    }

    freeModeElement.addEventListener('change', setViewMode);
    droneModeElement.addEventListener('change', setViewMode);

    viewer.trackedEntityChanged.addEventListener(function() {
        if (viewer.trackedEntity === drone) {
            freeModeElement.checked = false;
            droneModeElement.checked = true;
        }
    });

展现

-我们可以通过entity控制单个的，同样我们也可以控制它周边的。如下一般用不到没有研究

var shadowsElement = document.getElementById('shadows');
    var neighborhoodsElement =  document.getElementById('neighborhoods');

    shadowsElement.addEventListener('change', function (e) {
        viewer.shadows = e.target.checked;
    });

    neighborhoodsElement.addEventListener('change', function (e) {
        neighborhoods.show = e.target.checked;
    });

    // Finally, wait for the initial city to be ready before removing the loading indicator.
    var loadingIndicator = document.getElementById('loadingIndicator');
    loadingIndicator.style.display = 'block';
    city.readyPromise.then(function () {
        loadingIndicator.style.display = 'none';
    });