Chapter 346: Frustum

Core Idea

Frustums are used to determine what is inside the camera's field of view. They help speed up the rendering process - objects which lie outside a camera's frustum can safely be excluded from rendering.

This class is mainly intended for use internally by a renderer.

Key Concepts

• planes : Array.<Plane>: This array holds the planes that enclose the frustum.

Reference Tables

Constructor

Signature
new Frustum( p0 : Plane, p1 : Plane, p2 : Plane, p3 : Plane, p4 : Plane, p5 : Plane )

Properties

Property	Description
.planes : Array.<Plane>	This array holds the planes that enclose the frustum.

Methods

Method	Description
.clone() : Frustum	Returns a new frustum with copied values from this instance.
.containsPoint( point : Vector3 ) : boolean	Returns true if the given point lies within the frustum.
.copy( frustum : Frustum ) : Frustum	Copies the values of the given frustum to this instance.
.intersectsBox( box : Box3 ) : boolean	Returns true if the given bounding box is intersecting this frustum.
.intersectsObject( object : Object3D ) : boolean	Returns true if the 3D object's bounding sphere is intersecting this frustum.
.intersectsSphere( sphere : Sphere ) : boolean	Returns true if the given bounding sphere is intersecting this frustum.
.intersectsSprite( sprite : Sprite ) : boolean	Returns true if the given sprite is intersecting this frustum.
.set( p0 : Plane, p1 : Plane, p2 : Plane, p3 : Plane, p4 : Plane, p5 : Plane ) : Frustum	Sets the frustum planes by copying the given planes.
`.setFromProjectionMatrix( m : Matrix4, coordinateSystem : WebGLCoordinateSystem	WebGPUCoordinateSystem, reversedDepth : boolean ) : Frustum`

Key Takeaways

1. Most relevant properties: planes.
2. Key methods: clone, containsPoint, copy, intersectsBox.

Connects To

• Source: src/math/Frustum.js