KBE3D / KBCore / Cesium / Occluder

类: Occluder

Creates an Occluder derived from an object's position and radius, as well as the camera position. The occluder can be used to determine whether or not other objects are visible or hidden behind the visible horizon defined by the occluder and camera position.

示例

// 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);

参数

The bounding sphere surrounding the occluder.

参数

The coordinate of the viewer/camera.

属性

position

position: Cartesian3

The position of the occluder.

---

radius

radius: number

The radius of the occluder.

---

cameraPosition

cameraPosition: Cartesian3

The position of the camera.

方法

fromBoundingSphere()

static fromBoundingSphere(occluderBoundingSphere: BoundingSphere, cameraPosition: Cartesian3, result?: Occluder): Occluder

Creates an occluder from a bounding sphere and the camera position.

参数

occluderBoundingSphere

BoundingSphere

The bounding sphere surrounding the occluder.

cameraPosition

Cartesian3

The coordinate of the viewer/camera.

result?

Occluder

The object onto which to store the result.

返回

Occluder

The occluder derived from an object's position and radius, as well as the camera position.

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computeOccludeePoint()

static computeOccludeePoint(occluderBoundingSphere: BoundingSphere, occludeePosition: Cartesian3, positions: Cartesian3[]): any

Computes a point that can be used as the occludee position to the visibility functions. Use a radius of zero for the occludee radius. Typically, a user computes a bounding sphere around an object that is used for visibility; however it is also possible to compute a point that if seen/not seen would also indicate if an object is visible/not visible. This function is better called for objects that do not move relative to the occluder and is large, such as a chunk of terrain. You are better off not calling this and using the object's bounding sphere for objects such as a satellite or ground vehicle.

参数

occluderBoundingSphere

BoundingSphere

The bounding sphere surrounding the occluder.

occludeePosition

Cartesian3

The point where the occludee (bounding sphere of radius 0) is located.

positions

Cartesian3[]

List of altitude points on the horizon near the surface of the occluder.

返回

any

An object containing two attributes: occludeePoint and valid which is a boolean value.

示例

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);

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computeOccludeePointFromRectangle()

static computeOccludeePointFromRectangle(rectangle: Rectangle, ellipsoid?: Ellipsoid): any

Computes a point that can be used as the occludee position to the visibility functions from a rectangle.

参数

rectangle

Rectangle

The rectangle used to create a bounding sphere.

ellipsoid?

Ellipsoid

The ellipsoid used to determine positions of the rectangle.

返回

any

An object containing two attributes: occludeePoint and valid which is a boolean value.

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isPointVisible()

isPointVisible(occludee: Cartesian3): boolean

Determines whether or not a point, the <code>occludee</code>, is hidden from view by the occluder.

参数

occludee

Cartesian3

The point surrounding the occludee object.

返回

boolean

true if the occludee is visible; otherwise false.

示例

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

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isBoundingSphereVisible()

isBoundingSphereVisible(occludee: BoundingSphere): boolean

Determines whether or not a sphere, the <code>occludee</code>, is hidden from view by the occluder.

参数

occludee

BoundingSphere

The bounding sphere surrounding the occludee object.

返回

boolean

true if the occludee is visible; otherwise false.

示例

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

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computeVisibility()

computeVisibility(occludeeBS: BoundingSphere): Visibility

Determine to what extent an occludee is visible (not visible, partially visible, or fully visible).

参数

occludeeBS

BoundingSphere

The bounding sphere of the occludee.

返回

Visibility

Visibility.NONE if the occludee is not visible, Visibility.PARTIAL if the occludee is partially visible, or Visibility.FULL if the occludee is fully visible.

示例

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

构造函数

构造函数

new Occluder(occluderBoundingSphere: BoundingSphere, cameraPosition: Cartesian3): Occluder

参数

occluderBoundingSphere

BoundingSphere

cameraPosition

Cartesian3

返回

Occluder