CullingVolume

A culling volume defined by planes.

Static Members

CullingVolume.MASK_OUTSIDE

For plane masks (as used in CullingVolume#computeVisibilityWithPlaneMask), this special value represents the case where the object bounding volume is entirely outside the culling volume.

CullingVolume.MASK_INSIDE

For plane masks (as used in CullingVolume.computeVisibilityWithPlaneMask), this value represents the case where the object bounding volume is entirely inside the culling volume.

CullingVolume.MASK_INDETERMINATE

For plane masks (as used inCullingVolume.computeVisibilityWithPlaneMask), this value represents the case where the object bounding volume (may) intersect all planes of the culling volume.

Methods

constructor([planes : Plane[]])

• planes=[] An array of clipping 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.

fromBoundingSphere(boundingSphere : BoundingSphere)

Constructs a culling volume from a bounding sphere. Creates six planes that create a box containing the sphere. The planes are aligned to the x, y, and z axes in world coordinates.

• boundingSphere The bounding sphere used to create the culling volume.

computeVisibility(boundingVolume : Object) : Interset

Determines whether a bounding volume intersects the culling volume.

• boundingVolume The bounding volume whose intersection with the culling volume is to be tested.

Returns

• INTERSECTION.OUTSIDE, INTERSECTION.INTERSECTING, or INTERSECTION.INSIDE.

computeVisibilityWithPlaneMask(boundingVolume : Object, parentPlaneMask : Number) : Number

Determines whether a bounding volume intersects the culling volume.

• boundingVolume The bounding volume whose intersection with the culling volume is to be tested.
• parentPlaneMask A bit mask from the boundingVolume's parent's check against the same culling volume, such that if planeMask & (1 << planeIndex) === 0, for k < 31, then the parent (and therefore this) volume is completely inside plane[planeIndex] and that plane check can be skipped.

Returns

• A plane mask as described above (which can be applied to this boundingVolume's children).

Attribution

This class was ported from Cesium under the Apache 2 License.