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Billboard

Billboard

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A viewport-aligned image positioned in the 3D scene, that is created and rendered using a BillboardCollection. A billboard is created and its initial properties are set by calling BillboardCollection#add.


Example billboards

Performance:

Reading a property, e.g., Billboard#show, is constant time. Assigning to a property is constant time but results in CPU to GPU traffic when BillboardCollection#update is called. The per-billboard traffic is the same regardless of how many properties were updated. If most billboards in a collection need to be updated, it may be more efficient to clear the collection with BillboardCollection#removeAll and add new billboards instead of modifying each one.

Throws:
  • DeveloperError : scaleByDistance.far must be greater than scaleByDistance.near
  • DeveloperError : translucencyByDistance.far must be greater than translucencyByDistance.near
  • DeveloperError : pixelOffsetScaleByDistance.far must be greater than pixelOffsetScaleByDistance.near
Demo:
See:
Source:

Members

:{Cartesian3} value The aligned axis.

Gets and 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.
Example
// Example 1.
// Have the billboard up vector point north
billboard.alignedAxis = Cesium.Cartesian3.UNIT_Z;

// Example 2.
// Have the billboard point east.
billboard.alignedAxis = Cartesian3.UNIT_Z;
billboard.rotation = -Cesium.Math.PI_OVER_TWO;

// Example 3.
// Reset the aligned axis
billboard.alignedAxis = Cesium.Cartesian3.ZERO;

Gets and 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 0.0 makes the billboard transparent, and 1.0 makes the billboard opaque.

default
 alpha : 0.5

The red, green, blue, and alpha values are indicated by value's red, green, blue, and alpha properties as shown in Example 1. These components range from 0.0 (no intensity) to 1.0 (full intensity).
Example
// Example 1. Assign yellow.
b.color = Cesium.Color.YELLOW;

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

:Cartesian3

Gets and sets the 3D Cartesian offset applied to this billboard in eye coordinates. Eye coordinates is a left-handed coordinate system, where x points towards the viewer's right, y points up, and z points into the screen. Eye coordinates use the same scale as world and model coordinates, which is typically meters.

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.

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.

b.eyeOffset = new Cartesian3(0.0, 8000000.0, 0.0);

:Number

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

:{HorizontalOrigin} value The horizontal origin.

Gets and sets the horizontal origin of this billboard, which determines if the billboard is to the left, center, or right of its position.


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

:Object

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

:Number

Gets and sets the image index

:Cartesian2

Gets and 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 bottom, left corner of the canvas; x increases from left to right, and y increases from bottom to top.

default
 b.pixeloffset = new Cartesian2(50, -25);
The billboard's origin is indicated by the yellow point.

:NearFarScalar

Gets and 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 upper and lower 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.
Example
// 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);

// Example 2.
// disable pixel offset by distance
b.pixelOffsetScaleByDistance = undefined;

:Cartesian3

Gets and sets the Cartesian position of this billboard.

:Number

Gets and sets the rotation angle in radians.

:Number

Gets and sets the uniform scale that is multiplied with the billboard's image size in pixels. A scale of 1.0 does not change the size of the billboard; a scale greater than 1.0 enlarges the billboard; a positive scale less than 1.0 shrinks the billboard.


From left to right in the above image, the scales are 0.5, 1.0, and 2.0.

:NearFarScalar

Gets and 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 upper and lower 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.
Example
// 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);

// Example 2.
// disable scaling by distance
b.scaleByDistance = undefined;

: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.

:NearFarScalar

Gets and 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 upper and lower 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.
Example
// 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);

// Example 2.
// disable translucency by distance
b.translucencyByDistance = undefined;

:VerticalOrigin

Gets and sets the vertical origin of this billboard, which determines if the billboard is to the above, below, or at the center of its position.


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

:Number

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

<static> :DeveloperError

Computes the screen-space position of the billboard's origin, taking into account eye and pixel offsets. The screen space origin is the bottom, left corner of the canvas; x increases from left to right, and y increases from bottom to top.
Example
console.log(b.computeScreenSpacePosition(scene).toString());
See:

Methods

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

Parameters:
Name Type Description
other Billboard The billboard to compare for equality.
Returns:
Boolean true if the billboards are equal; otherwise, false.