@web-engine-dev/math

---

@web-engine-dev/math / Frustum

Class: Frustum

A view frustum defined by 6 planes. Used for frustum culling. Planes face inward (positive half-space is inside the frustum).

Example

const viewProj = projMatrix.mulMat(viewMatrix);
const frustum = Frustum.fromViewProjection(viewProj);

// Cull objects outside the frustum
if (frustum.intersectsBox(object.bounds) !== FrustumIntersection.Outside) {
  render(object);
}

Constructors

Constructor

new Frustum(planes): Frustum

Creates a frustum from 6 planes. Order: left, right, bottom, top, near, far.

Parameters

planes

[Plane, Plane, Plane, Plane, Plane, Plane]

Returns

Frustum

Properties

planes

readonly planes: readonly [Plane, Plane, Plane, Plane, Plane, Plane]

Accessors

bottom

Get Signature

get bottom(): Plane

Returns

Plane

---

far

Get Signature

get far(): Plane

Returns

Plane

---

left

Get Signature

get left(): Plane

Returns

Plane

---

near

Get Signature

get near(): Plane

Returns

Plane

---

right

Get Signature

get right(): Plane

Returns

Plane

---

top

Get Signature

get top(): Plane

Returns

Plane

Methods

containsPoint()

containsPoint(point): boolean

Tests if a point is inside the frustum.

Parameters

point

Vec3

Returns

boolean

---

cullBox()

cullBox(box): boolean

Fast AABB culling test (just checks if outside). This is the most common operation for frustum culling.

Parameters

box

AABB

Returns

boolean

---

cullSphere()

cullSphere(center, radius): boolean

Fast sphere culling test (just checks if outside).

Parameters

center

Vec3

radius

number

Returns

boolean

---

getCorners()

getCorners(): Vec3[]

Computes the 8 corners of the frustum. Useful for debug visualization.

Returns

Vec3[]

---

intersectsBox()

intersectsBox(box): FrustumIntersection

Tests if an AABB intersects or is inside the frustum. Zero-allocation: uses inline scalar math instead of constructing Vec3.

Parameters

box

AABB

Returns

FrustumIntersection

---

intersectsCorners()

intersectsCorners(corners): FrustumIntersection

Tests if an oriented bounding box (8 corners) is inside the frustum.

Parameters

corners

Vec3[]

Returns

FrustumIntersection

---

intersectsSphere()

intersectsSphere(center, radius): FrustumIntersection

Tests if a sphere intersects or is inside the frustum.

Parameters

center

Vec3

radius

number

Returns

FrustumIntersection

---

setFromViewProjectionMut()

setFromViewProjectionMut(viewProjection): this

Updates this frustum from a view-projection matrix (no allocations).

Parameters

viewProjection

Mat4

Returns

this

---

toString()

toString(): string

Returns

string

---

fromPerspective()

static fromPerspective(fovY, aspect, near, far, viewMatrix): Frustum

Creates a frustum from perspective parameters.

Parameters

fovY

number

aspect

number

near

number

far

number

viewMatrix

Mat4

Returns

Frustum

---

fromViewProjection()

static fromViewProjection(viewProjection): Frustum

Creates a frustum from a view-projection matrix. The matrix should be the combined projection * view matrix.

Parameters

viewProjection

Mat4

Returns

Frustum

---

fromViewProjectionOut()

static fromViewProjectionOut(viewProjection, out): Frustum

Updates an existing frustum from a view-projection matrix (no allocations).

Parameters

viewProjection

Mat4

out

Frustum

Returns

Frustum