OrthographicFrustum

new OrthographicFrustum()

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.
Example:
var maxRadii = ellipsoid.maximumRadius;

var frustum = new Cesium.OrthographicFrustum();
frustum.right = maxRadii * Cesium.Math.PI;
frustum.left = -c.frustum.right;
frustum.top = c.frustum.right * (canvas.clientHeight / canvas.clientWidth);
frustum.bottom = -c.frustum.top;
frustum.near = 0.01 * maxRadii;
frustum.far = 50.0 * maxRadii;

Members

bottom :Number

The bottom clipping plane.
Default Value: undefined

far :Number

The distance of the far plane.
Default Value: 500000000.0;

left :Number

The left clipping plane.
Default Value: undefined

near :Number

The distance of the near plane.
Default Value: 1.0

projectionMatrix :Matrix4

Gets the orthographic projection matrix computed from the view frustum.
The right clipping plane.
Default Value: undefined

top :Number

The top clipping plane.
Default Value: undefined

Methods

clone(result)OrthographicFrustum

Returns a duplicate of a OrthographicFrustum instance.
Name Type Description
result OrthographicFrustum optional The object onto which to store the result.
Returns:
The modified result parameter or a new PerspectiveFrustum instance if one was not provided.

computeCullingVolume(position, direction, up)CullingVolume

Creates a culling volume for this frustum.
Name Type Description
position Cartesian3 The eye position.
direction Cartesian3 The view direction.
up Cartesian3 The up direction.
Returns:
A culling volume at the given position and orientation.
Example:
// Check if a bounding volume intersects the frustum.
var cullingVolume = frustum.computeCullingVolume(cameraPosition, cameraDirection, cameraUp);
var intersect = cullingVolume.computeVisibility(boundingVolume);

equals(other)Boolean

Compares the provided OrthographicFrustum componentwise and returns true if they are equal, false otherwise.
Name Type Description
other OrthographicFrustum optional The right hand side OrthographicFrustum.
Returns:
true if they are equal, false otherwise.

getPixelSize(drawingBufferDimensions, distance, result)Cartesian2

Returns the pixel's width and height in meters.
Name Type Default Description
drawingBufferDimensions Cartesian2 A Cartesian2 with width and height in the x and y properties, respectively.
distance Number near plane distance optional The distance to the near plane in meters.
result Cartesian2 optional The object onto which to store the result.
Returns:
The modified result parameter or a new instance of Cartesian2 with the pixel's width and height in the x and y properties, respectively.
Throws:
  • DeveloperError : drawingBufferDimensions.x must be greater than zero.
  • DeveloperError : drawingBufferDimensions.y must be greater than zero.
Example:
// Example 1
// Get the width and height of a pixel.
var pixelSize = camera.frustum.getPixelSize(new Cesium.Cartesian2(canvas.clientWidth, canvas.clientHeight));