KBE3D / KBCore / Cesium / PerspectiveOffCenterFrustum

类: PerspectiveOffCenterFrustum

The viewing frustum is defined by 6 planes. Each plane is represented by a Cartesian4 object, where the x, y, and z components define the unit vector normal to the plane, and the w component is the distance of the plane from the origin/camera position.

示例

const frustum = new Cesium.PerspectiveOffCenterFrustum({
    left : -1.0,
    right : 1.0,
    top : 1.0,
    bottom : -1.0,
    near : 1.0,
    far : 100.0
});

参数

An object with the following properties:

参数

The left clipping plane distance.

参数

The right clipping plane distance.

参数

The top clipping plane distance.

参数

The bottom clipping plane distance.

参数

The near clipping plane distance.

参数

The far clipping plane distance.

属性

left

left: number | undefined

Defines the left clipping plane.

---

right

right: number | undefined

Defines the right clipping plane.

---

top

top: number | undefined

Defines the top clipping plane.

---

bottom

bottom: number | undefined

Defines the bottom clipping plane.

---

near

near: number

The distance of the near plane.

---

far

far: number

The distance of the far plane.

---

projectionMatrix

readonly projectionMatrix: Matrix4

Gets the perspective projection matrix computed from the view frustum. The projection matrix will be recomputed if any frustum parameters have changed.

---

infiniteProjectionMatrix

readonly infiniteProjectionMatrix: Matrix4

Gets the perspective projection matrix computed from the view frustum with an infinite far plane.

方法

computeCullingVolume()

computeCullingVolume(position: Cartesian3, direction: Cartesian3, up: Cartesian3): CullingVolume

Creates a culling volume for this frustum.

参数

position

Cartesian3

The eye position.

direction

Cartesian3

The view direction.

up

Cartesian3

The up direction.

返回

CullingVolume

A culling volume at the given position and orientation.

示例

// Check if a bounding volume intersects the frustum.
const cullingVolume = frustum.computeCullingVolume(cameraPosition, cameraDirection, cameraUp);
const intersect = cullingVolume.computeVisibility(boundingVolume);

---

getPixelDimensions()

getPixelDimensions(drawingBufferWidth: number, drawingBufferHeight: number, distance: number, pixelRatio: number, result: Cartesian2): Cartesian2

Returns the pixel's width and height in meters.

参数

drawingBufferWidth

number

The width of the drawing buffer.

drawingBufferHeight

number

The height of the drawing buffer.

distance

number

The distance to the near plane in meters.

pixelRatio

number

The scaling factor from pixel space to coordinate space.

result

Cartesian2

The object onto which to store the result.

返回

Cartesian2

The modified result parameter or a new instance of Cartesian2 with the pixel's width and height in the x and y properties, respectively.

Examples

// Example 1
// Get the width and height of a pixel.
const pixelSize = camera.frustum.getPixelDimensions(scene.drawingBufferWidth, scene.drawingBufferHeight, 1.0, scene.pixelRatio, new Cesium.Cartesian2());

// Example 2
// Get the width and height of a pixel if the near plane was set to 'distance'.
// For example, get the size of a pixel of an image on a billboard.
const position = camera.position;
const direction = camera.direction;
const toCenter = Cesium.Cartesian3.subtract(primitive.boundingVolume.center, position, new Cesium.Cartesian3());      // vector from camera to a primitive
const toCenterProj = Cesium.Cartesian3.multiplyByScalar(direction, Cesium.Cartesian3.dot(direction, toCenter), new Cesium.Cartesian3()); // project vector onto camera direction vector
const distance = Cesium.Cartesian3.magnitude(toCenterProj);
const pixelSize = camera.frustum.getPixelDimensions(scene.drawingBufferWidth, scene.drawingBufferHeight, distance, scene.pixelRatio, new Cesium.Cartesian2());

---

clone()

clone(result?: PerspectiveOffCenterFrustum): PerspectiveOffCenterFrustum

Returns a duplicate of a PerspectiveOffCenterFrustum instance.

参数

result?

PerspectiveOffCenterFrustum

The object onto which to store the result.

返回

PerspectiveOffCenterFrustum

The modified result parameter or a new PerspectiveFrustum instance if one was not provided.

---

equals()

equals(other?: PerspectiveOffCenterFrustum): boolean

Compares the provided PerspectiveOffCenterFrustum componentwise and returns <code>true</code> if they are equal, <code>false</code> otherwise.

参数

other?

PerspectiveOffCenterFrustum

The right hand side PerspectiveOffCenterFrustum.

返回

boolean

true if they are equal, false otherwise.

---

equalsEpsilon()

equalsEpsilon(other: PerspectiveOffCenterFrustum, relativeEpsilon: number, absoluteEpsilon?: number): boolean

Compares the provided PerspectiveOffCenterFrustum componentwise and returns <code>true</code> if they pass an absolute or relative tolerance test, <code>false</code> otherwise.

参数

other

PerspectiveOffCenterFrustum

The right hand side PerspectiveOffCenterFrustum.

relativeEpsilon

number

The relative epsilon tolerance to use for equality testing.

absoluteEpsilon?

number

The absolute epsilon tolerance to use for equality testing.

返回

boolean

true if this and other are within the provided epsilon, false otherwise.

构造函数

构造函数

new PerspectiveOffCenterFrustum(options?: { left?: number; right?: number; top?: number; bottom?: number; near?: number; far?: number; }): PerspectiveOffCenterFrustum

参数

options?

left?

number

right?

number

top?

number

bottom?

number

near?

number

far?

number

返回

PerspectiveOffCenterFrustum