在 Mapbox 中添加一个 three.js 场景作为自定义层

Question

我正在尝试使用基于本教程的方法在 Mapbox 中可视化 three.js 场景：https://docs.mapbox.com/mapbox-gl-js/example/add-3d-model/

我有一个名为“threescene”的准备好的场景，我将它添加到自定义图层的场景中。它包含建筑物的几何形状。坐标在 WGS84 中，看起来它们会在教程代码中正确转换。

但是，图层根本不显示。我不知道我是否应该对坐标做其他事情，或者是否还有其他问题。我已经尝试标准化场景中的坐标。

我的代码如下：

    mapboxgl.accessToken = 'pk.eyJ1IjoiamxpZW1wdCIsImEiOiJjanpzZHNhOGwxZ3RjM2JuenBpcjN4eTh3In0.dnO_1v0NDfRMZBhv-hVvjQ';
    var map = window.map = new mapboxgl.Map({
        container: 'map',
        style: 'mapbox://styles/mapbox/light-v10',
        zoom: 18,
        center: [6.8309373573, 53.0475174735], // min of bbox
        pitch: 60,
        antialias: true // create the gl context with MSAA antialiasing, so custom layers are antialiased
  });

    // parameters to ensure the model is georeferenced correctly on the map
    var modelOrigin = [6.8309373573, 53.0475174735]; // min of bbox
    var modelAltitude = 0;
    var modelRotate = [Math.PI / 2, 0, 0];

    var modelAsMercatorCoordinate = mapboxgl.MercatorCoordinate.fromLngLat(modelOrigin, modelAltitude);

    // transformation parameters to position, rotate and scale the 3D model onto the map
    var modelTransform = {
        translateX: modelAsMercatorCoordinate.x,
        translateY: modelAsMercatorCoordinate.y,
        translateZ: modelAsMercatorCoordinate.z,
        rotateX: modelRotate[0],
        rotateY: modelRotate[1],
        rotateZ: modelRotate[2],
        /* Since our 3D model is in real world meters, a scale transform needs to be
         * applied since the CustomLayerInterface expects units in MercatorCoordinates.
         */
        scale: modelAsMercatorCoordinate.meterInMercatorCoordinateUnits()
    };

    var THREE = window.THREE;

    // configuration of the custom layer for a 3D model per the CustomLayerInterface
    var customLayer = {
        id: '3d-model',
        type: 'custom',
        renderingMode: '3d',
        onAdd: function(map, gl) {
            this.camera = new THREE.Camera();
            this.scene = new THREE.Scene();

            this.scene.add(threescene); // here I include my scene

            // create two three.js lights to illuminate the model
            var directionalLight = new THREE.DirectionalLight(0xffffff);
            directionalLight.position.set(0, -70, 100).normalize();
            this.scene.add(directionalLight);

            var directionalLight2 = new THREE.DirectionalLight(0xffffff);
            directionalLight2.position.set(0, 70, 100).normalize();
            this.scene.add(directionalLight2);

            this.map = map;

            // use the Mapbox GL JS map canvas for three.js
            this.renderer = new THREE.WebGLRenderer({
                canvas: map.getCanvas(),
                context: gl,
                antialias: true
            });

            this.renderer.autoClear = false;
        },
        render: function(gl, matrix) {
            var rotationX = new THREE.Matrix4().makeRotationAxis(new THREE.Vector3(1, 0, 0), modelTransform.rotateX);
            var rotationY = new THREE.Matrix4().makeRotationAxis(new THREE.Vector3(0, 1, 0), modelTransform.rotateY);
            var rotationZ = new THREE.Matrix4().makeRotationAxis(new THREE.Vector3(0, 0, 1), modelTransform.rotateZ);

            var m = new THREE.Matrix4().fromArray(matrix);
            var l = new THREE.Matrix4().makeTranslation(modelTransform.translateX, modelTransform.translateY, modelTransform.translateZ)
                .scale(new THREE.Vector3(modelTransform.scale, -modelTransform.scale, modelTransform.scale))
                .multiply(rotationX)
                .multiply(rotationY)
                .multiply(rotationZ);

            this.camera.projectionMatrix.elements = matrix;
            this.camera.projectionMatrix = m.multiply(l);
            this.renderer.state.reset();
            this.renderer.render(this.scene, this.camera);
            this.map.triggerRepaint();
        }
    };

    map.on('style.load', function() {
        map.addLayer(customLayer, 'waterway-label');
  });

Answer 1

你说你的坐标在 WGS84 中，所以你说你的模型在 WGS84 中，它有度数单位，但后来在代码中你继承了 modelScale 以米为单位。

那么，您的模型的单位是米还是度，它是哪个坐标参考系？因为您需要根据此应用正确的比例变换。