Cesium 点线面文本模型贴地

1、entity 实体贴地（billboard 和 label 都可以配置）

可能还需要配合 heightReference: Cesium.HeightReference.CLAMP_TO_GROUND 的设置。

entity.billboard.disableDepthTestDistance = Number.POSITIVE_INFINITY; //去掉地形遮挡

entity.label.disableDepthTestDistance = Number.POSITIVE_INFINITY; //去掉地形遮挡2、polyline 线条设置贴地 clampToGround: true

3、polygon 贴地似乎不需要设置任何东西。但通常你需要结合边界线 polyline，这个 polyline 需要设置 clampToGround: true

// positions 的格式是一个笛卡尔数组 [, , , ...]

// 可以用这种方式转经纬度数组：const positions = Cesium.Cartesian3.fromDegreesArray(points)

const entity = viewer.entities.add({

name: 'name' + key,

polygon: {

hierarchy: new Cesium.PolygonHierarchy(positions),

material: Cesium.Color.fromCssColorString('#9b9bdd').withAlpha(0.35),

classificationType: Cesium.ClassificationType.BOTH, // classificationType: ClassificationType.TERRAIN,

},

polyline: {

positions: positions,

width: 2,

material: Cesium.Color.WHITE.withAlpha(0.5),

clampToGround: true,

},

})4、geojson 数据源设置贴地（未实战测试）

let promise = Cesium.GeoJsonDataSource.load(_geojsondata, { clampToGround: true })

// ---

const geoJsonDataSource = new Cesium.CustomDataSource('聚合图')

viewer.dataSources.add(geoJsonDataSource, { clampToGround: true })5、gltf 模型贴地

据说模型贴地需要设置 heightReference: Cesium.HeightReference.CLAMP_TO_GROUND，但我自测其实不需要。先记着吧。

viewer.entities.add({

id: `flag-1`,

name: "flag",

position: Cesium.Cartesian3.fromDegrees(...item.position),

model: {

heightReference: Cesium.HeightReference.CLAMP_TO_GROUND, // 让模型在地形上紧贴

scale: 10,

uri: './static/models/flag.glb'

}

})6、entities label 贴地

const label = viewer.entities.add({

position: position,

label: {

text: name,

fillColor: Cesium.Color.fromCssColorString('#ffffff'),

font: '28px',

horizontalOrigin: Cesium.HorizontalOrigin.CENTER,

verticalOrigin: Cesium.VerticalOrigin.TOP,

scaleByDistance: new Cesium.NearFarScalar(0, 1, 1200, 1),

distanceDisplayCondition: new Cesium.DistanceDisplayCondition(0, 10000),

// eyeOffset: new Cesium.Cartesian3(0, 0, -100),

// pixelOffset: new Cesium.Cartesian2(0, -40),

heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,

disableDepthTestDistance: Number.POSITIVE_INFINITY,

},

})