Occluder

Members

cameraPosition : Cartesian3

相机的位置。

position : Cartesian3

遮挡物的位置。

radius : Number

遮挡物的半径。

Methods

staticSuperMap3D.Occluder.computeOccludeePoint(occluderBoundingSphere, occludeePosition, positions) → Object

计算一个点，该点可用作可见性函数的被遮挡位置。 通常情况下，用户会计算一个物体周围的包围球，用于显示可见性；但也可以计算一个点，如果看到/看不到，这个点也会显示物体是否可见/不可见。 对于相对于遮挡器不会移动且体积较大的物体（如一大块地形），最好调用该函数。 对于卫星或地面车辆等物体，最好不要调用此函数，而是使用物体的包围球来显示。 如卫星或地面车辆。

Name	Type	Description
occluderBoundingSphere	BoundingSphere	遮挡物周围的包围球。
occludeePosition	Cartesian3	遮挡物(半径为0的包围球)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是一个boolean。

Throws:

• DeveloperError : 位置必须至少包含一个要素。
• DeveloperError : occludeePosition 的值必须是 occluderBoundingSphere.center 以外的值。

Example:

var cameraPosition = new SuperMap3D.Cartesian3(0, 0, 0);
var occluderBoundingSphere = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -8), 2);
var occluder = new SuperMap3D.Occluder(occluderBoundingSphere, cameraPosition);
var positions = [new SuperMap3D.Cartesian3(-0.25, 0, -5.3), new SuperMap3D.Cartesian3(0.25, 0, -5.3)];
var tileOccluderSphere = SuperMap3D.BoundingSphere.fromPoints(positions);
var occludeePosition = tileOccluderSphere.center;
var occludeePt = SuperMap3D.Occluder.computeOccludeePoint(occluderBoundingSphere, occludeePosition, positions);

staticSuperMap3D.Occluder.computeOccludeePointFromRectangle(rectangle, ellipsoid) → Object

根据矩形计算一个可用作可见度函数的遮挡位置的点。

Name	Type	Default	Description
rectangle	Rectangle		用来创建包围球的矩形。
ellipsoid	Ellipsoid	Ellipsoid.WGS84	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是一个boolean。

staticSuperMap3D.Occluder.fromBoundingSphere(occluderBoundingSphere, cameraPosition, result) → Occluder

根据包围球和相机位置创建遮挡器。

Name	Type	Description
occluderBoundingSphere	BoundingSphere	遮挡物周围的包围球。
cameraPosition	Cartesian3	T观察者/相机的坐标。
result	Occluder	optional 存储结果的对象。

Returns:

根据物体的位置和半径以及相机位置得出的遮挡物。

computeVisibility(occludeeBS) → Number

确定遮挡物的可见程度（不可见、部分可见或完全可见）。

Name	Type	Description
occludeeBS	BoundingSphere	被遮挡者的包围球。

Returns:

如果被遮挡物不可见，则显示 Visibility.NONE；如果被遮挡物部分可见，则显示 Visibility.PARTIAL；如果被遮挡物完全可见，则显示 Visibility.FULL。

Example:

var sphere1 = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -1.5), 0.5);
var sphere2 = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -2.5), 0.5);
var cameraPosition = new SuperMap3D.Cartesian3(0, 0, 0);
var occluder = new SuperMap3D.Occluder(sphere1, cameraPosition);
occluder.computeVisibility(sphere2); //returns Visibility.NONE

See:

• Occluder#isVisible

isBoundingSphereVisible(occludee) → Boolean

确定一个球体（即被遮挡者）是否被遮挡物遮挡。

Name	Type	Description
occludee	BoundingSphere	被遮挡物体周围的包围球。

Returns:

如果遮挡物可见，则为 true；否则为 false。

Example:

var cameraPosition = new SuperMap3D.Cartesian3(0, 0, 0);
var littleSphere = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -1), 0.25);
var occluder = new SuperMap3D.Occluder(littleSphere, cameraPosition);
var bigSphere = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -3), 1);
occluder.isBoundingSphereVisible(bigSphere); //returns true

See:

• Occluder#computeVisibility

isPointVisible(occludee) → Boolean

确定一个点，即 occludee 是否被遮挡物从视图中隐藏。

Name	Type	Description
occludee	Cartesian3	被遮挡物体周围的点。

Returns:

如果遮挡物可见，则为 true；否则为 false。

Example:

var cameraPosition = new SuperMap3D.Cartesian3(0, 0, 0);
var littleSphere = new SuperMap3D.BoundingSphere(new SuperMap3D.Cartesian3(0, 0, -1), 0.25);
var occluder = new SuperMap3D.Occluder(littleSphere, cameraPosition);
var point = new SuperMap3D.Cartesian3(0, 0, -3);
occluder.isPointVisible(point); //returns true

See:

• Occluder#computeVisibility