如何从 geojson 文件中获取多边形的坐标并从中挤出 3D 多边形？

Question

我正在尝试构建自定义多边形并使用图层数据的 geojson 格式将其拉伸到所需的高度。但是，我无法让图层显示在地图上。

这是我的代码目前的样子：

map.on('load', function() {
    map.addLayer({
        "id": "points",
        "type": "fill-extrusion",
        "source": {
            "type": "geojson",
            "data": {
                "type": "FeatureCollection",
                "features": [{
                    "type": "Feature",
                    "properties": {
                        "height": 20
                    },
                    "geometry": {
                        "type": "Polygon",
                        "coordinates": [[-77.95156674578604,43.21028611031018],[-77.9515685764367,43.21023621803456],[-77.95164127121708,43.21023640149863],[-77.95163950226289,43.20994159756599],[-77.95156746849948,43.20994229766657],[-77.95156608216422,43.20984647340193],[-77.95163884784701,43.2098471878642],[-77.95163818870492,43.20974779426955],[-77.95156665824665,43.20974844351096],[-77.95156615562892,43.2096483942845],[-77.95163707195606,43.20964807835471],[-77.95163793551596,43.20955241242493],[-77.95156647756606,43.20955241987652],[-77.9515664774183,43.2094545892833],[-77.95163793511105,43.20945458922404],[-77.95163696894726,43.20935746267753],[-77.95156551159552,43.20935675861833],[-77.95156647716871,43.20929763788168],[-77.95105728862093,43.20929848258431],[-77.95105728634326,43.20935651174059],[-77.95094326166087,43.20935664235909],[-77.9509445324407,43.2094533024724],[-77.95105528277132,43.20945365396392], [-77.95105519319713,43.20955170962569],[-77.9509434596672,43.20955220425741],[-77.95094421091157,43.20964816606944],[-77.95105501443713,43.20964756032618],[-77.95105491497931,43.20974624410085], [-77.95094329958742,43.20974576773256],[-77.95094365714365,43.20984690983914],[-77.95105721793563,43.20984632462195],[-77.95105737381726,43.20994209364298], [-77.95094302334114,43.2099429224098], [-77.95094306509297,43.21003748562214],[-77.95105440575118,43.21003746846881],[-77.95105570050066,43.21013103703177],[-77.95094276571092,43.21013059432006],[-77.95094112502309,43.21023730976442],[-77.95105416431622,43.21023720143463],[-77.95105549775089,43.21028580291442],[-77.95156674578604,43.21028611031018]]
                    }
                }]
            }
        },
        "paint": {
            "fill-extrusion-color": "#aaa",
            "fill-extrusion-height": ['get', 'height']
        }
    });
});

Answer 1

Polygon 是 GeoJSON 中的 LineString 数组（例如，参见 https://en.wikipedia.org/wiki/GeoJSON#Geometries）。因此，在您的情况下，坐标应如下所示：

"coordinates": [[[-77.95156674578604,43.21028611031018],[-77.9515685764367,43.21023621803456],[-77.95164127121708,43.21023640149863],[-77.95163950226289,43.20994159756599],[-77.95156746849948,43.20994229766657],[-77.95156608216422,43.20984647340193],[-77.95163884784701,43.2098471878642],[-77.95163818870492,43.20974779426955],[-77.95156665824665,43.20974844351096],[-77.95156615562892,43.2096483942845],[-77.95163707195606,43.20964807835471],[-77.95163793551596,43.20955241242493],[-77.95156647756606,43.20955241987652],[-77.9515664774183,43.2094545892833],[-77.95163793511105,43.20945458922404],[-77.95163696894726,43.20935746267753],[-77.95156551159552,43.20935675861833],[-77.95156647716871,43.20929763788168],[-77.95105728862093,43.20929848258431],[-77.95105728634326,43.20935651174059],[-77.95094326166087,43.20935664235909],[-77.9509445324407,43.2094533024724],[-77.95105528277132,43.20945365396392], [-77.95105519319713,43.20955170962569],[-77.9509434596672,43.20955220425741],[-77.95094421091157,43.20964816606944],[-77.95105501443713,43.20964756032618],[-77.95105491497931,43.20974624410085], [-77.95094329958742,43.20974576773256],[-77.95094365714365,43.20984690983914],[-77.95105721793563,43.20984632462195],[-77.95105737381726,43.20994209364298], [-77.95094302334114,43.2099429224098], [-77.95094306509297,43.21003748562214],[-77.95105440575118,43.21003746846881],[-77.95105570050066,43.21013103703177],[-77.95094276571092,43.21013059432006],[-77.95094112502309,43.21023730976442],[-77.95105416431622,43.21023720143463],[-77.95105549775089,43.21028580291442],[-77.95156674578604,43.21028611031018]]]

如何从 geojson 文件中获取多边形的坐标并从中挤出 3D 多边形？

How can I take coordinates for a polygon from a geojson file and extrude a 3D polygon from that?

mapbox-gl-js