Class Frustum

constructor

• new Frustum(): Frustum

• Creates a new Frustum instance. Initializes all planes and corner arrays with default values.

  Returns Frustum

bottom

corners

left

right

top

zFar

zNear

culling

• culling(meshComponent): boolean

• Performs frustum culling test against a mesh component's bounding box. Uses optimized frustum-AABB intersection algorithm to determine visibility.

  Parameters

  • meshComponent: MeshComponent

    The mesh component to test for culling

  Returns boolean

  false if the mesh is completely outside the frustum (should be culled), true if the mesh is inside or intersects the frustum (should be rendered)

  Remarks

  This method uses a two-phase approach:

  1. Tests if the AABB is completely outside any frustum plane
  2. Tests if all frustum corners are outside any AABB face

  The algorithm is based on the optimized frustum culling technique described at: https://iquilezles.org/articles/frustumcorrect/

  Example

  const frustum = new Frustum();
  frustum.update(viewMatrix, projectionMatrix);
  
  if (frustum.culling(meshComponent)) {
    // Render the mesh
    renderMesh(meshComponent);
  }
  // Otherwise, skip rendering (culled)
  Copy

getPlane

• getPlane(i): MutableVector4

• Retrieves a specific frustum plane by index.

  Parameters

  • i: number

    The plane index (0-5)

    • 0: Top plane
    • 1: Bottom plane
    • 2: Right plane
    • 3: Left plane
    • 4: Near plane
    • 5: Far plane

  Returns MutableVector4

  The plane as a Vector4 where (x,y,z) represents the plane normal and w represents the distance from the origin

  Throws

  Throws an error if the plane index is invalid (not 0-5)

  Example

  const frustum = new Frustum();
  const topPlane = frustum.getPlane(0);    // Get top plane
  const nearPlane = frustum.getPlane(4);   // Get near plane
  Copy

update

• update(viewMatrix, projectionMatrix): void

• Updates this view frustum data from the view and projection matrices. Calculates the six frustum planes and eight corner vertices in world space. This method should be called whenever the camera's view or projection matrix changes.

  Parameters

  • viewMatrix: Matrix44

    The view matrix that transforms from world space to view space
  • projectionMatrix: Matrix44

    The projection matrix that transforms from view space to clip space

  Returns void

  Remarks

  The frustum planes are calculated using the combined view-projection matrix. Corner vertices are computed by transforming normalized device coordinates back to world space. The planes are stored as Vector4 where (x,y,z) is the normal and w is the distance from origin.