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
-
The bottom clipping plane.
-
Default Value:
undefined -
The distance of the far plane.
-
Default Value:
500000000.0; -
The left clipping plane.
-
Default Value:
undefined -
The distance of the near plane.
-
Default Value:
1.0 -
readonlyprojectionMatrix : Matrix4
-
Gets the orthographic projection matrix computed from the view frustum.
-
The right clipping plane.
-
Default Value:
undefined -
The top clipping plane.
-
Default Value:
undefined
Methods
-
clone(result) → OrthographicFrustum
-
Returns a duplicate of a OrthographicFrustum instance.
Name Type Description resultOrthographicFrustum 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 positionCartesian3 The eye position. directionCartesian3 The view direction. upCartesian3 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); -
Compares the provided OrthographicFrustum componentwise and returns
trueif they are equal,falseotherwise.Name Type Description otherOrthographicFrustum optional The right hand side OrthographicFrustum. Returns:
trueif they are equal,falseotherwise. -
getPixelDimensions(drawingBufferWidth, drawingBufferHeight, distance, result) → Cartesian2
-
Returns the pixel's width and height in meters.
Name Type Description drawingBufferWidthNumber The width of the drawing buffer. drawingBufferHeightNumber The height of the drawing buffer. distanceNumber The distance to the near plane in meters. resultCartesian2 The object onto which to store the result. Returns:
The modified result parameter or a new instance ofCartesian2with the pixel's width and height in the x and y properties, respectively.Throws:
-
DeveloperError : drawingBufferWidth must be greater than zero.
-
DeveloperError : drawingBufferHeight must be greater than zero.
Example:
// Example 1 // Get the width and height of a pixel. var pixelSize = camera.frustum.getPixelDimensions(scene.drawingBufferWidth, scene.drawingBufferHeight, 0.0, new Cesium.Cartesian2()); -
