KBE3D

Appearance

KBE3D / KBCore / Cesium / Billboard

类: Billboard ​

<div class="notice"> A billboard is created and its initial properties are set by calling BillboardCollection#add. Do not call the constructor directly. </div> A viewport-aligned image positioned in the 3D scene, that is created and rendered using a BillboardCollection. <br /><br /> <div align='center'> <img src='/Images/Billboard.png' width='400' height='300' /><br /> Example billboards </div>

参数 ​

Object describing initialization options

参数 ​

Instance of BillboardCollection

属性 ​

show ​

show: boolean

Determines if this billboard will be shown. Use this to hide or show a billboard, instead of removing it and re-adding it to the collection.

position ​

position: Cartesian3

Gets or sets the Cartesian position of this billboard.

heightReference ​

heightReference: HeightReference

Gets or sets the height reference of this billboard.

pixelOffset ​

pixelOffset: Cartesian2

Gets or sets the pixel offset in screen space from the origin of this billboard. This is commonly used to align multiple billboards and labels at the same position, e.g., an image and text. The screen space origin is the top, left corner of the canvas; <code>x</code> increases from left to right, and <code>y</code> increases from top to bottom. <br /><br /> <div align='center'> <table border='0' cellpadding='5'><tr> <td align='center'><code>default</code><br/><img src='/Images/Billboard.setPixelOffset.default.png' width='250' height='188' /></td> <td align='center'><code>b.pixeloffset = new Cartesian2(50, 25);</code><br/><img src='/Images/Billboard.setPixelOffset.x50y-25.png' width='250' height='188' /></td> </tr></table> The billboard's origin is indicated by the yellow point. </div>

scaleByDistance ​

scaleByDistance: NearFarScalar

Gets or sets near and far scaling properties of a Billboard based on the billboard's distance from the camera. A billboard's scale will interpolate between the NearFarScalar#nearValue and NearFarScalar#farValue while the camera distance falls within the lower and upper bounds of the specified NearFarScalar#near and NearFarScalar#far. Outside of these ranges the billboard's scale remains clamped to the nearest bound. If undefined, scaleByDistance will be disabled.

Examples ​

ts
// Example 1.
// Set a billboard's scaleByDistance to scale by 1.5 when the
// camera is 1500 meters from the billboard and disappear as
// the camera distance approaches 8.0e6 meters.
b.scaleByDistance = new Cesium.NearFarScalar(1.5e2, 1.5, 8.0e6, 0.0);
ts
// Example 2.
// disable scaling by distance
b.scaleByDistance = undefined;

translucencyByDistance ​

translucencyByDistance: NearFarScalar

Gets or sets near and far translucency properties of a Billboard based on the billboard's distance from the camera. A billboard's translucency will interpolate between the NearFarScalar#nearValue and NearFarScalar#farValue while the camera distance falls within the lower and upper bounds of the specified NearFarScalar#near and NearFarScalar#far. Outside of these ranges the billboard's translucency remains clamped to the nearest bound. If undefined, translucencyByDistance will be disabled.

Examples ​

ts
// Example 1.
// Set a billboard's translucency to 1.0 when the
// camera is 1500 meters from the billboard and disappear as
// the camera distance approaches 8.0e6 meters.
b.translucencyByDistance = new Cesium.NearFarScalar(1.5e2, 1.0, 8.0e6, 0.0);
ts
// Example 2.
// disable translucency by distance
b.translucencyByDistance = undefined;

pixelOffsetScaleByDistance ​

pixelOffsetScaleByDistance: NearFarScalar

Gets or sets near and far pixel offset scaling properties of a Billboard based on the billboard's distance from the camera. A billboard's pixel offset will be scaled between the NearFarScalar#nearValue and NearFarScalar#farValue while the camera distance falls within the lower and upper bounds of the specified NearFarScalar#near and NearFarScalar#far. Outside of these ranges the billboard's pixel offset scale remains clamped to the nearest bound. If undefined, pixelOffsetScaleByDistance will be disabled.

Examples ​

ts
// Example 1.
// Set a billboard's pixel offset scale to 0.0 when the
// camera is 1500 meters from the billboard and scale pixel offset to 10.0 pixels
// in the y direction the camera distance approaches 8.0e6 meters.
b.pixelOffset = new Cesium.Cartesian2(0.0, 1.0);
b.pixelOffsetScaleByDistance = new Cesium.NearFarScalar(1.5e2, 0.0, 8.0e6, 10.0);
ts
// Example 2.
// disable pixel offset by distance
b.pixelOffsetScaleByDistance = undefined;

eyeOffset ​

eyeOffset: Cartesian3

Gets or sets the 3D Cartesian offset applied to this billboard in eye coordinates. Eye coordinates is a left-handed coordinate system, where <code>x</code> points towards the viewer's right, <code>y</code> points up, and <code>z</code> points into the screen. Eye coordinates use the same scale as world and model coordinates, which is typically meters. <br /><br /> An eye offset is commonly used to arrange multiple billboards or objects at the same position, e.g., to arrange a billboard above its corresponding 3D model. <br /><br /> Below, the billboard is positioned at the center of the Earth but an eye offset makes it always appear on top of the Earth regardless of the viewer's or Earth's orientation. <br /><br /> <div align='center'> <table border='0' cellpadding='5'><tr> <td align='center'><img src='/Images/Billboard.setEyeOffset.one.png' width='250' height='188' /></td> <td align='center'><img src='/Images/Billboard.setEyeOffset.two.png' width='250' height='188' /></td> </tr></table> <code>b.eyeOffset = new Cartesian3(0.0, 8000000.0, 0.0);</code><br /><br /> </div>

horizontalOrigin ​

horizontalOrigin: HorizontalOrigin

Gets or sets the horizontal origin of this billboard, which determines if the billboard is to the left, center, or right of its anchor position. <br /><br /> <div align='center'> <img src='/Images/Billboard.setHorizontalOrigin.png' width='648' height='196' /><br /> </div>

示例 ​

ts
// Use a bottom, left origin
b.horizontalOrigin = Cesium.HorizontalOrigin.LEFT;
b.verticalOrigin = Cesium.VerticalOrigin.BOTTOM;

verticalOrigin ​

verticalOrigin: VerticalOrigin

Gets or sets the vertical origin of this billboard, which determines if the billboard is to the above, below, or at the center of its anchor position. <br /><br /> <div align='center'> <img src='/Images/Billboard.setVerticalOrigin.png' width='695' height='175' /><br /> </div>

示例 ​

ts
// Use a bottom, left origin
b.horizontalOrigin = Cesium.HorizontalOrigin.LEFT;
b.verticalOrigin = Cesium.VerticalOrigin.BOTTOM;

scale ​

scale: number

Gets or sets the uniform scale that is multiplied with the billboard's image size in pixels. A scale of <code>1.0</code> does not change the size of the billboard; a scale greater than <code>1.0</code> enlarges the billboard; a positive scale less than <code>1.0</code> shrinks the billboard. <br /><br /> <div align='center'> <img src='/Images/Billboard.setScale.png' width='400' height='300' /><br/> From left to right in the above image, the scales are <code>0.5</code>, <code>1.0</code>, and <code>2.0</code>. </div>

color ​

color: Color

Gets or sets the color that is multiplied with the billboard's texture. This has two common use cases. First, the same white texture may be used by many different billboards, each with a different color, to create colored billboards. Second, the color's alpha component can be used to make the billboard translucent as shown below. An alpha of <code>0.0</code> makes the billboard transparent, and <code>1.0</code> makes the billboard opaque. <br /><br /> <div align='center'> <table border='0' cellpadding='5'><tr> <td align='center'><code>default</code><br/><img src='/Images/Billboard.setColor.Alpha255.png' width='250' height='188' /></td> <td align='center'><code>alpha : 0.5</code><br/><img src='/Images/Billboard.setColor.Alpha127.png' width='250' height='188' /></td> </tr></table> </div> <br /> The red, green, blue, and alpha values are indicated by <code>value</code>'s <code>red</code>, <code>green</code>, <code>blue</code>, and <code>alpha</code> properties as shown in Example 1. These components range from <code>0.0</code> (no intensity) to <code>1.0</code> (full intensity).

Examples ​

ts
// Example 1. Assign yellow.
b.color = Cesium.Color.YELLOW;
ts
// Example 2. Make a billboard 50% translucent.
b.color = new Cesium.Color(1.0, 1.0, 1.0, 0.5);

rotation ​

rotation: number

Gets or sets the rotation angle in radians.

alignedAxis ​

alignedAxis: Cartesian3

Gets or sets the aligned axis in world space. The aligned axis is the unit vector that the billboard up vector points towards. The default is the zero vector, which means the billboard is aligned to the screen up vector.

Examples ​

ts
// Example 1.
// Have the billboard up vector point north
billboard.alignedAxis = Cesium.Cartesian3.UNIT_Z;
ts
// Example 2.
// Have the billboard point east.
billboard.alignedAxis = Cesium.Cartesian3.UNIT_Z;
billboard.rotation = -Cesium.Math.PI_OVER_TWO;
ts
// Example 3.
// Reset the aligned axis
billboard.alignedAxis = Cesium.Cartesian3.ZERO;

width ​

width: number | undefined

Gets or sets a width for the billboard. If undefined, the image width will be used.

height ​

height: number | undefined

Gets or sets a height for the billboard. If undefined, the image height will be used.

sizeInMeters ​

sizeInMeters: boolean

Gets or sets if the billboard size is in meters or pixels. <code>true</code> to size the billboard in meters; otherwise, the size is in pixels.

distanceDisplayCondition ​

distanceDisplayCondition: DistanceDisplayCondition

Gets or sets the condition specifying at what distance from the camera that this billboard will be displayed.

disableDepthTestDistance ​

disableDepthTestDistance: number | undefined

Gets or sets the distance from the camera, beyond which, depth testing is disbaled—to, for example, prevent clipping against terrain. When set to <code>undefined</code> or <code>0</code>, the depth test is always applied. When set to <code>Number.POSITIVE_INFINITY</code>, the depth test is never applied.

id ​

id: any

Gets or sets the user-defined object returned when the billboard is picked.

image ​

image: string

<p> Gets or sets the image to be used for this billboard. If a texture has already been created for the given image, the existing texture is used. </p> <p> This property can be set to a loaded Image, a URL which will be loaded as an Image automatically, a canvas, or another billboard's image property (from the same billboard collection). </p>

示例 ​

ts
// load an image from a URL
b.image = 'some/image/url.png';

// assuming b1 and b2 are billboards in the same billboard collection,
// use the same image for both billboards.
b2.image = b1.image;

ready ​

readonly ready: boolean

When <code>true</code>, this billboard is ready to render, i.e., the image has been downloaded and the WebGL resources are created.

splitDirection ​

splitDirection: SplitDirection

Gets or sets the SplitDirection of this billboard.

方法 ​

setImage() ​

setImage(id: string, image: string | HTMLCanvasElement | Resource | HTMLImageElement | CreateImageCallback): void

<p> Sets the image to be used for this billboard. If a texture has already been created for the given id, the existing texture is used. </p> <p> This function is useful for dynamically creating textures that are shared across many billboards. Only the first billboard will actually call the function and create the texture, while subsequent billboards created with the same id will simply re-use the existing texture. </p> <p> To load an image from a URL, setting the Billboard#image property is more convenient. </p>

参数 ​

id ​

string

The id of the image. This can be any string that uniquely identifies the image.

image ​

The image to load. This parameter can either be a loaded Image or Canvas, a URL which will be loaded as an Image automatically, or a function which will be called to create the image if it hasn't been loaded already.

string | HTMLCanvasElement | Resource | HTMLImageElement | CreateImageCallback

返回 ​

void

示例 ​

ts
// create a billboard image dynamically
function drawImage(id) {
  // create and draw an image using a canvas
  const canvas = document.createElement('canvas');
  const context2D = canvas.getContext('2d');
  // ... draw image
  return canvas;
}
// drawImage will be called to create the texture
b.setImage('myImage', drawImage);

// subsequent billboards created in the same collection using the same id will use the existing
// texture, without the need to create the canvas or draw the image
b2.setImage('myImage', drawImage);

setImageSubRegion() ​

setImageSubRegion(id: string, subRegion: BoundingRectangle): void

Uses a sub-region of the image with the given id as the image for this billboard, measured in pixels from the bottom-left.

参数 ​

id ​

string

The id of the image to use.

subRegion ​

BoundingRectangle

The sub-region of the image.

返回 ​

void

computeScreenSpacePosition() ​

computeScreenSpacePosition(scene: Scene, result?: Cartesian2): Cartesian2

Computes the screen-space position of the billboard's origin, taking into account eye and pixel offsets. The screen space origin is the top, left corner of the canvas; <code>x</code> increases from left to right, and <code>y</code> increases from top to bottom.

参数 ​

scene ​

Scene

The scene.

result? ​

Cartesian2

The object onto which to store the result.

返回 ​

Cartesian2

The screen-space position of the billboard.

示例 ​

ts
console.log(b.computeScreenSpacePosition(scene).toString());

equals() ​

equals(other?: Billboard): boolean

Determines if this billboard equals another billboard. Billboards are equal if all their properties are equal. Billboards in different collections can be equal.

参数 ​

other? ​

Billboard

The billboard to compare for equality.

返回 ​

boolean

true if the billboards are equal; otherwise, false.

构造函数 ​

构造函数 ​

new Billboard(options: ConstructorOptions, billboardCollection: BillboardCollection): Billboard

参数 ​

options ​

ConstructorOptions

billboardCollection ​

BillboardCollection

返回 ​

Billboard

KBE3D @3.0.0 Copyright © 2024-present KBE3D

京ICP备2026003052号-1