摘要：前言基于架構的可視化平臺平面圖導航一中已經完成了面板與我們的場景的簡單交互，下面我們繼續完善并給頁加上鼠標懸停事件讓頁的標簽和我們場景中的一起動起來。

前言

基于WebGL架構的3D可視化平臺—平面圖導航（一）中已經完成了iframe面板與我們的3D場景的簡單交互，下面我們繼續完善并給iframe頁加上鼠標懸停事件讓iframe頁的img標簽和我們場景中的obj一起動起來。

實現

第一步，還是使用之前的場景接著上次的繼續，先編寫iframe頁。給每一個img標簽都加上onmouseover、onmouseout 事件。

第二步，房間里的物體不要要讓他“飛起來”，還要給他加一個“底座”。這里叫他SurveillanceCamera類，在自己編寫類的時候一定要注意，想要當前類生效一定要繼承THING.Thing，并且THING.factory.registerClass(‘ClassName’, ClassName);

class SurveillanceCamera extends THING.Thing {

constructor(app) {
    super(app);
    this.app = app;
    this.isFrustum = true;
    this.opacity = 1;
    this.color = 0xff00ff;
    this.vertices = [];
    this.near = 0.1;
    this.camera = null;
    this.node = new THREE.Object3D();
    this._frustum = new THREE.Frustum();
    this._projScreenMatrix = new THREE.Matrix4();

}

setup(param) {
    super.setup(param);
    this.fov = param["fov"];
    this.aspect = param["aspect"];
    this.far = param["far"];
    this.alpha = param["alpha"];
    this.lineAlpha = param["lineAlpha"];
    this.setupComplete(param);
}

setupComplete(param) {
    super.setupComplete(param);
    this.build();
}

build() {
    if (this.node.children.length > 0) {
        this.node.children = [];
    }

    if (this.camera != null) {
        this.camera = null;
    }

    var h = this.far * Math.tan(this.fov * 0.5 * 0.017453293);
    var w = this.aspect * h;

    var geometry = new THREE.Geometry();
    this.vertices = [new THREE.Vector3(0, 0, 0), new THREE.Vector3(w, -h, -this.far), new THREE.Vector3(w, h, -this.far), new THREE.Vector3(-w, h, -this.far), new THREE.Vector3(-w, -h, -this.far)];
    var faces = [new THREE.Face3(0, 1, 2), new THREE.Face3(0, 2, 3), new THREE.Face3(0, 3, 4), new THREE.Face3(0, 4, 1), new THREE.Face3(3, 4, 1), new THREE.Face3(3, 1, 2)];
    geometry.vertices = this.vertices;

    var line_mat = new THREE.LineBasicMaterial({
        color: "#b4f5f8",
        opacity: this.lineAlpha || 0.5,
    })

    var texture = THREE.ImageUtils.loadTexture("images/light2.png");
    texture.wrapS = THREE.RepeatWrapping;
    texture.wrapT = THREE.RepeatWrapping;
    var frustum_mat = new THREE.MeshBasicMaterial({
        color: "#0aa5ff",
        opacity: this.alpha || 0.5,
        transparent: true,
        side: THREE.DoubleSide,
    });
    var line_mesh = new THREE.Line(geometry, line_mat);

    var frustum_mesh = new THREE.Mesh(geometry, frustum_mat);
    geometry.faces = faces;
    this.node.add(frustum_mesh, line_mesh);

    this.camera = new THREE.PerspectiveCamera(this.fov, this.aspect, this.near, this.far);
    this.camera.position.set(this.position[0], this.position[1], this.position[2]);
    this.camera.rotation.copy(this.node.rotation);

    this.camera.updateMatrixWorld(true);
    this._updateFrustum();
}

setPosition() {
    this.camera.position.set(this.position[0], this.position[1], this.position[2]);
    this.camera.updateMatrixWorld(true);
    this._updateFrustum();
}

_updateFrustum() {
    if (this.camera) {
        this._projScreenMatrix.multiplyMatrices(this.camera.projectionMatrix, this.camera.matrixWorldInverse);
        this._frustum.setFromMatrix(this._projScreenMatrix);
    }
}

intersectsObject(object) {
    this._updateFrustum();
    return this._frustum.intersectsObject(object);
}

intersectsBox(box) {
    this._updateFrustum();
    return this._frustum.intersectsBox(box);
}

intersectsSphere(sphere) {
    this._updateFrustum();
    return this._frustum.intersectsSphere(sphere);
}

intersectsSprite(sprite) {
    this._updateFrustum();
    return this._frustum.intersectsSprite(sprite);
}

}

THING.factory.registerClass("SurveillanceCamera", SurveillanceCamera);

第三步，鼠標懸浮事件和鼠標離開事件，這里我們使用了之前創建的SurveillanceCamera類為obj加上了一個“底座”。

//鼠標懸浮事件
function onMouseOver(targetObj,viewPoint) {

if (currentModule != null)
    return;
overModule = app.query(targetObj)[0];
overModule.style.boundingBox = true;
overModule.moveTo({
    "offset": [0, 6, 0],
    "time": 80,
});
sCamera = app.create({
    type: "SurveillanceCamera",
    name: "SurveillanceCamera_",
    position:app.query(viewPoint)[0].position,
    fov: 65,
    aspect: 1.3,
    far: 6,
});
sCamera.angleX = 90;
sCamera.style.opacity = 0.1;

}
//鼠標離開事件
function onMouseOut(targetObj) {

if (currentModule != null)
    return;
if (sCamera) {
    sCamera.destroy();
    sCamera = null;
}
outModule = overModule;
outModule.style.boundingBox = false;
outModule.stopMoving();
outModule.position = [0, 0, 0];
outModule = null;

}

演示地址：EXAMPLE

總結

利用iframe與ThingJS進行交互完成了平面圖導航功能，通過自制的HTML界面，嵌入ThingJS的面板中，形成一個可自定義的導航界面，通過偏移實現相應的視覺效果。

制作一個視錐，達到投放影像的效果，這里運用面向對象的方式是為了，能夠更快捷的創建視錐，起到復用的作用。

在制作過程中，將物體懸浮的過程時出現了問題，發現如果快速的操作鼠標，物體不會達到預期的視覺效果，例如，鼠標快速的在兩個導航圖之間切換時，對應的兩個物體會不斷的上升，盡管將上升與還原的速度加快，也依然無法解決問題。最后解決的辦法是：新添加一個變量，將上一次懸浮的物體記錄下來，就是文中的 outModule，通過對 outModule 多帶帶操作來解決影響問題。