maptalks 开发GIS地图（26）maptalks.three.19

1. 自定义高架，每个高架路线为经纬度数组，

其中包括经度、纬度、高度。

2. 调用addLine函数添加对象。

 function addLine(lnglats, name, width = 8) {
            const lineString = new maptalks.LineString(lnglats);
            const altitudes = lnglats.map(lnglat => {
                return lnglat[2] / 10;
            });
            lineString.setProperties({ altitudes });
            const line = new Bridge(lineString, { width }, material, threeLayer);
            line.setToolTip(name, {
                showTimeout: 0,
                eventsPropagation: true,
                dx: 10
            });


            const { coordinates, height } = line.getOptions();
            const alts = coordinates.map(c => {
                return c[2];
            })
            const pLine = new maptalks.LineString(coordinates);
            pLine.setProperties({
                altitudes: alts
            });
            const edgeLine = new Line(pLine, { altitude: -0.05, offset: -0.05 }, edgeLineMaterial, threeLayer);
            const edgeLine1 = new Line(pLine, { altitude: height + 0.05, offset: height + 0.05 }, edgeLineMaterial, threeLayer);

            const centerLine = new Line(lineString, { altitude: 1.1, offset: 1.1 }, linematerial, threeLayer);

            threeLayer.addMesh([line, centerLine, edgeLine, edgeLine1]);
            meshes.push(line);

            helperMeshes.push(centerLine, edgeLine, edgeLine1);
        }

3. 其中的红黑效果，最后发现是通过不同的材质组合构成的。

   var material = new THREE.MeshBasicMaterial({ color: 'rgb(12,12,17)', transparent: true, wireframe: false });
        var highlightmaterial = new THREE.MeshBasicMaterial({ color: 'yellow', transparent: true });

        const material1 = new THREE.MeshLambertMaterial({
            color: '#000'
        });
        const highlightmaterial1 = new THREE.MeshLambertMaterial({
            color: 'red'
        });

        var edgeLineMaterial = new THREE.LineBasicMaterial({
            color: '#fff',
            transparent: true,
            opacity: 0.6
        });

        var linematerial = new THREE.LineDashedMaterial({
            color: '#fff',
            dashSize: 0.05,
            gapSize: 0.05
        });

4. 页面显示

5. 源码地址

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