KBE3D / KBCore / Cesium / GroundPolylinePrimitive

类: GroundPolylinePrimitive

A GroundPolylinePrimitive represents a polyline draped over the terrain or 3D Tiles in the Scene. <p> Only to be used with GeometryInstances containing GroundPolylineGeometry. </p>

示例

// 1. Draw a polyline on terrain with a basic color material

const instance = new Cesium.GeometryInstance({
  geometry : new Cesium.GroundPolylineGeometry({
     positions : Cesium.Cartesian3.fromDegreesArray([
         -112.1340164450331, 36.05494287836128,
         -112.08821010582645, 36.097804071380715
     ]),
     width : 4.0
  }),
  id : 'object returned when this instance is picked and to get/set per-instance attributes'
});

scene.groundPrimitives.add(new Cesium.GroundPolylinePrimitive({
  geometryInstances : instance,
  appearance : new Cesium.PolylineMaterialAppearance()
}));

// 2. Draw a looped polyline on terrain with per-instance color and a distance display condition.
// Distance display conditions for polylines on terrain are based on an approximate terrain height
// instead of true terrain height.

const instance2 = new Cesium.GeometryInstance({
  geometry : new Cesium.GroundPolylineGeometry({
     positions : Cesium.Cartesian3.fromDegreesArray([
         -112.1340164450331, 36.05494287836128,
         -112.08821010582645, 36.097804071380715,
         -112.13296079730024, 36.168769146801104
     ]),
     loop : true,
     width : 4.0
  }),
  attributes : {
     color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.fromCssColorString('green').withAlpha(0.7)),
     distanceDisplayCondition : new Cesium.DistanceDisplayConditionGeometryInstanceAttribute(1000, 30000)
  },
  id : 'object returned when this instance is picked and to get/set per-instance attributes'
});

scene.groundPrimitives.add(new Cesium.GroundPolylinePrimitive({
  geometryInstances : instance2,
  appearance : new Cesium.PolylineColorAppearance()
}));

参数

Object with the following properties:

参数

GeometryInstances containing GroundPolylineGeometry

参数

The Appearance used to render the polyline. Defaults to a white color Material on a PolylineMaterialAppearance.

参数

Determines if this primitive will be shown.

参数

When <code>true</code>, geometry vertex attributes are interleaved, which can slightly improve rendering performance but increases load time.

参数

When <code>true</code>, the primitive does not keep a reference to the input <code>geometryInstances</code> to save memory.

参数

When <code>true</code>, each geometry instance will only be pickable with Scene#pick. When <code>false</code>, GPU memory is saved.

参数

Determines if the primitive will be created asynchronously or block until ready. If false initializeTerrainHeights() must be called first.

参数

Determines whether terrain, 3D Tiles or both will be classified.

参数

For debugging only. Determines if this primitive's commands' bounding spheres are shown.

参数

For debugging only. Determines if the shadow volume for each geometry in the primitive is drawn. Must be <code>true</code> on creation to have effect.

属性

geometryInstances

readonly geometryInstances: any[] | GeometryInstance

The geometry instances rendered with this primitive. This may be <code>undefined</code> if <code>options.releaseGeometryInstances</code> is <code>true</code> when the primitive is constructed. <p> Changing this property after the primitive is rendered has no effect. </p>

---

appearance

appearance: Appearance

The Appearance used to shade this primitive. Each geometry instance is shaded with the same appearance. Some appearances, like PolylineColorAppearance allow giving each instance unique properties.

---

show

show: boolean

Determines if the primitive will be shown. This affects all geometry instances in the primitive.

---

classificationType

classificationType: ClassificationType

Determines whether terrain, 3D Tiles or both will be classified.

---

debugShowBoundingVolume

debugShowBoundingVolume: boolean

This property is for debugging only; it is not for production use nor is it optimized. <p> Draws the bounding sphere for each draw command in the primitive. </p>

---

interleave

readonly interleave: boolean

Determines if geometry vertex attributes are interleaved, which can slightly improve rendering performance.

---

releaseGeometryInstances

readonly releaseGeometryInstances: boolean

When <code>true</code>, the primitive does not keep a reference to the input <code>geometryInstances</code> to save memory.

---

allowPicking

readonly allowPicking: boolean

When <code>true</code>, each geometry instance will only be pickable with Scene#pick. When <code>false</code>, GPU memory is saved.

---

asynchronous

readonly asynchronous: boolean

Determines if the geometry instances will be created and batched on a web worker.

---

ready

readonly ready: boolean

Determines if the primitive is complete and ready to render. If this property is true, the primitive will be rendered the next time that GroundPolylinePrimitive#update is called.

---

debugShowShadowVolume

readonly debugShowShadowVolume: boolean

This property is for debugging only; it is not for production use nor is it optimized. <p> If true, draws the shadow volume for each geometry in the primitive. </p>

方法

initializeTerrainHeights()

static initializeTerrainHeights(): Promise<void>

Initializes the minimum and maximum terrain heights. This only needs to be called if you are creating the GroundPolylinePrimitive synchronously.

返回

Promise<void>

A promise that will resolve once the terrain heights have been loaded.

---

isSupported()

static isSupported(scene: Scene): boolean

Checks if the given Scene supports GroundPolylinePrimitives. GroundPolylinePrimitives require support for the WEBGL_depth_texture extension.

参数

scene

Scene

The current scene.

返回

boolean

Whether or not the current scene supports GroundPolylinePrimitives.

---

update()

update(): void

Called when Viewer or CesiumWidget render the scene to get the draw commands needed to render this primitive. <p> Do not call this function directly. This is documented just to list the exceptions that may be propagated when the scene is rendered: </p>

返回

void

---

getGeometryInstanceAttributes()

getGeometryInstanceAttributes(id: any): any

Returns the modifiable per-instance attributes for a GeometryInstance.

参数

id

any

The id of the GeometryInstance.

返回

any

The typed array in the attribute's format or undefined if the is no instance with id.

示例

const attributes = primitive.getGeometryInstanceAttributes('an id');
attributes.color = Cesium.ColorGeometryInstanceAttribute.toValue(Cesium.Color.AQUA);
attributes.show = Cesium.ShowGeometryInstanceAttribute.toValue(true);

---

isDestroyed()

isDestroyed(): boolean

Returns true if this object was destroyed; otherwise, false. <p> If this object was destroyed, it should not be used; calling any function other than <code>isDestroyed</code> will result in a DeveloperError exception. </p>

返回

boolean

true if this object was destroyed; otherwise, false.

---

destroy()

destroy(): void

Destroys the WebGL resources held by this object. Destroying an object allows for deterministic release of WebGL resources, instead of relying on the garbage collector to destroy this object. <p> Once an object is destroyed, it should not be used; calling any function other than <code>isDestroyed</code> will result in a DeveloperError exception. Therefore, assign the return value (<code>undefined</code>) to the object as done in the example. </p>

返回

void

示例

e = e && e.destroy();

构造函数

构造函数

new GroundPolylinePrimitive(options?: { geometryInstances?: any[] | GeometryInstance; appearance?: Appearance; show?: boolean; interleave?: boolean; releaseGeometryInstances?: boolean; allowPicking?: boolean; asynchronous?: boolean; classificationType?: ClassificationType; debugShowBoundingVolume?: boolean; debugShowShadowVolume?: boolean; }): GroundPolylinePrimitive

参数

options?

geometryInstances?

any[] | GeometryInstance

appearance?

Appearance

show?

boolean

interleave?

boolean

releaseGeometryInstances?

boolean

allowPicking?

boolean

asynchronous?

boolean

classificationType?

ClassificationType

debugShowBoundingVolume?

boolean

debugShowShadowVolume?

boolean

返回

GroundPolylinePrimitive