How to merge multiple lines with gaps in threejs

问题

I am successfully loading a dataset with polygon data that represent buildings in a city. So every polygon represents a single building. In Threejs I can successfully represent them, but when I try to merg the separate lines into one geometry, all the lines are connected (I understand why this makes sense, since all the vertices are added to the same collection).

But how do I merge those separate building polygons into a single geometry without having the lines of the separate building polygons connected to each other?

The code I have right now:

var geometry = new THREE.Geometry();

            for (var i = 0; i < data.length; i++) {
                var temp = new THREE.Geometry();
                var polygon = data[i];
                for (var j = 0; j < polygon.length; j++) {
                    temp.vertices.push(new THREE.Vector3(polygon[j][0], polygon[j][1], 0));
                }
                temp.vertices.push(new THREE.Vector3(polygon[0][0], polygon[0][1], 0));

                THREE.GeometryUtils.merge(geometry, temp);
            }
            scene.add(new THREE.Line(geometry, buildingMaterial, THREE.LineStrip));

data is the variable that contains all the polygon data for the buildings.

回答1:

Solved:

            var cube = new THREE.Geometry();

            for (var i = 0; i < data.length; i++) {
                var shape = new THREE.Shape(_.uniq(_.map(data[i], function(d) { return new THREE.Vector3(d[0], d[1], 100); })));
                shape.extrude({amount: 100})
                var points = shape.createPointsGeometry();
                THREE.GeometryUtils.merge(cube, shape.extrude({amount: -1 - Math.random() * 1, bevelSegments: 0, steps: 1 , bevelSegments: 0, bevelSize: 0, bevelThickness: 0}));

            }

            var mesh = new THREE.Mesh(cube, new THREE.MeshBasicMaterial({color: 0x333333, wireframe: false}));
            scene.add(mesh);

来源：https://stackoverflow.com/questions/16773982/how-to-merge-multiple-lines-with-gaps-in-threejs