maptalks 开发GIS地图（19）maptalks.three.12

1. 建筑物轮廓为建筑的边缘线，内部不进行填充颜色，只有边缘线进行勾勒，效果也不错。

2. 将建筑物填充为黑色方块，获取建筑物的边线

        //default values
        var OPTIONS = {
            altitude: 0
        };

        //https://zhuanlan.zhihu.com/p/199353080
        class OutLine extends maptalks.BaseObject {
            constructor(mesh, options, material, layer) {
                options = maptalks.Util.extend({}, OPTIONS, options, { layer });
                super();
                //Initialize internal configuration
                // https://github.com/maptalks/maptalks.three/blob/1e45f5238f500225ada1deb09b8bab18c1b52cf2/src/BaseObject.js#L135
                this._initOptions(options);

                const edges = new THREE.EdgesGeometry(mesh.getObject3d().geometry, 1);
                const lineS = new THREE.LineSegments(edges, material);
                this._createGroup();
                this.getObject3d().add(lineS);
                //Initialize internal object3d
                // https://github.com/maptalks/maptalks.three/blob/1e45f5238f500225ada1deb09b8bab18c1b52cf2/src/BaseObject.js#L140

                //set object3d position
                this.getObject3d().position.copy(mesh.getObject3d().position);
            }
        }

3. 页面显示

4. 源码地址

https://github.com/WhatGIS/maptalkMap/tree/main/threelayer/demo