Occluder

new Cesium.Occluder(occluderBoundingSphere, cameraPosition)
engine/Source/Core/Occluder.js 29

创建从对象的位置和半径以及摄像机位置派生的 Occluder。 遮挡物可用于确定其他对象是否可见或隐藏在 由 Occluder 和 Camera Position 定义的可见地平线。
Name Type Description
occluderBoundingSphere BoundingSphere 围绕遮挡物的边界球体。
cameraPosition Cartesian3 查看器/相机的坐标。
Example:
// Construct an occluder one unit away from the origin with a radius of one.
const cameraPosition = Cesium.Cartesian3.ZERO;
const occluderBoundingSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 1);
const occluder = new Cesium.Occluder(occluderBoundingSphere, cameraPosition);

Members

cameraPosition : Cartesian3
engine/Source/Core/Occluder.js 81

相机的位置。

position : Cartesian3
engine/Source/Core/Occluder.js 59

遮挡物的位置。

radius : number
engine/Source/Core/Occluder.js 70

遮挡物的半径。

Methods

static Cesium.Occluder.computeOccludeePoint(occluderBoundingSphere, occludeePosition, positions) → object
engine/Source/Core/Occluder.js 404

计算可用作可见性函数的遮挡位置的点。 对遮挡对象半径使用零的半径。 通常，用户会计算一个围绕 用于可见性的对象;但是，也可以计算一个点，如果 seen/not seen 还将指示对象是否可见/不可见。 这个功能比较好 适用于不相对于遮挡物移动且较大的对象，例如 地形。 最好不要调用此函数，而是将对象的边界球体用于对象 例如卫星或地面车辆。
Name Type Description
occluderBoundingSphere BoundingSphere 围绕遮挡物的边界球体。
occludeePosition Cartesian3 被遮挡物(半径为 0 的边界球体)所在的点。
positions Array.<Cartesian3> 遮挡物表面附近地平线上的高度点列表。
Returns:
包含两个属性的对象：occludeePoint 和 valid 的 Boolean 值。
Throws:
  • DeveloperError : positions must contain at least one element.
  • DeveloperError : occludeePosition must have a value other than occluderBoundingSphere.center.
Example:
const cameraPosition = new Cesium.Cartesian3(0, 0, 0);
const occluderBoundingSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -8), 2);
const occluder = new Cesium.Occluder(occluderBoundingSphere, cameraPosition);
const positions = [new Cesium.Cartesian3(-0.25, 0, -5.3), new Cesium.Cartesian3(0.25, 0, -5.3)];
const tileOccluderSphere = Cesium.BoundingSphere.fromPoints(positions);
const occludeePosition = tileOccluderSphere.center;
const occludeePt = Cesium.Occluder.computeOccludeePoint(occluderBoundingSphere, occludeePosition, positions);

static Cesium.Occluder.computeOccludeePointFromRectangle(rectangle, ellipsoid) → object
engine/Source/Core/Occluder.js 503

计算一个点，该点可用作矩形中可见性函数的遮挡位置。
Name Type Default Description
rectangle Rectangle 用于创建边界球体的矩形。
ellipsoid Ellipsoid Ellipsoid.default optional 用于确定矩形位置的椭球体。
Returns:
包含两个属性的对象：occludeePoint 和 valid 的 Boolean 值。

static Cesium.Occluder.fromBoundingSphere(occluderBoundingSphere, cameraPosition, result) → Occluder
engine/Source/Core/Occluder.js 145

从边界球体和相机位置创建遮挡物。
Name Type Description
occluderBoundingSphere BoundingSphere 围绕遮挡物的边界球体。
cameraPosition Cartesian3 查看器/相机的坐标。
result Occluder optional 要在其上存储结果的对象。
Returns:
从对象的位置和半径以及相机位置派生的遮挡物。

computeVisibility(occludeeBS) → Visibility
engine/Source/Core/Occluder.js 304

确定被遮挡对象的可见程度 (不可见、部分可见或完全可见)。
Name Type Description
occludeeBS BoundingSphere 被遮挡对象的边界球体。
Returns:
Visibility.NONE 如果被遮挡对象不可见， Visibility.PARTIAL(如果被遮挡对象部分可见)，或者 Visibility.FULL(如果被遮挡对象完全可见)。
Example:
const sphere1 = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1.5), 0.5);
const sphere2 = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -2.5), 0.5);
const cameraPosition = new Cesium.Cartesian3(0, 0, 0);
const occluder = new Cesium.Occluder(sphere1, cameraPosition);
occluder.computeVisibility(sphere2); //returns Visibility.NONE

isBoundingSphereVisible(occludee) → boolean
engine/Source/Core/Occluder.js 225

确定球体(被遮挡物)是否被遮挡物隐藏。
Name Type Description
occludee BoundingSphere 包围被遮挡物体的边界球。
Returns:
如果 occludee 可见，则为true;否则为 false。
Example:
const cameraPosition = new Cesium.Cartesian3(0, 0, 0);
const littleSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 0.25);
const occluder = new Cesium.Occluder(littleSphere, cameraPosition);
const bigSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -3), 1);
occluder.isBoundingSphereVisible(bigSphere); //returns true
See:

isPointVisible(occludee) → boolean
engine/Source/Core/Occluder.js 189

Determines whether or not a point, the occludee, is hidden from view by the occluder.
Name Type Description
occludee Cartesian3 The point surrounding the occludee object.
Returns:
true if the occludee is visible; otherwise false.
Example:
const cameraPosition = new Cesium.Cartesian3(0, 0, 0);
const littleSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 0.25);
const occluder = new Cesium.Occluder(littleSphere, cameraPosition);
const point = new Cesium.Cartesian3(0, 0, -3);
occluder.isPointVisible(point); //returns true
See:
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