BVH Class Reference

Bounding Volume Hierarchy for fast ray intersection queries. More...

#include <bvh.h>

Classes
struct	BVHNode

Public Member Functions
	BVH ()
	Create a new and empty BVH.
virtual	~BVH ()
	Release all resources.
void	clear ()
	Release all resources.
void	addShape (Shape *shape)
	Register a shape for inclusion in the BVH. More...
void	build ()
	Build the BVH.
bool	rayIntersect (const Ray3f &ray, Intersection &its, bool shadowRay=false) const
	Intersect a ray against all shapes registered with the BVH. More...
uint32_t	getShapeCount () const
	Return the total number of shapes registered with the BVH.
uint32_t	getPrimitiveCount () const
	Return the total number of internally represented primitives.
Shape *	getShape (uint32_t idx)
	Return one of the registered shapes.
const Shape *	getShape (uint32_t idx) const
	Return one of the registered shapes (const version)
const BoundingBox3f &	getBoundingBox () const

Protected Member Functions
uint32_t	findShape (uint32_t &idx) const
	Compute the shape and primitive indices corresponding to a primitive index used by the underlying generic BVH implementation.
BoundingBox3f	getBoundingBox (uint32_t index) const
Point3f	getCentroid (uint32_t index) const
std::pair< float, uint32_t >	statistics (uint32_t index=0) const
	Compute internal tree statistics.

Friends
class	BVHBuildTask

Detailed Description

Bounding Volume Hierarchy for fast ray intersection queries.

This class builds a Bounding Volume Hierarchy (BVH) using a greedy divide and conquer build strategy, which locally maximizes a criterion known as the Surface Area Heuristic (SAH) to obtain a tree that is particularly well-suited for ray intersection queries.

Construction of a BVH is generally slow; the implementation here runs in parallel to accelerate this process much as possible. For details on how this works, refer to the paper

"Fast and Parallel Construction of SAH-based Bounding Volume Hierarchies" by Ingo Wald (Proc. IEEE/EG Symposium on Interactive Ray Tracing, 2007)

Author

Wenzel Jakob

Definition at line 43 of file bvh.h.

Member Function Documentation

addShape()

void BVH::addShape

(

Shape *

shape

)

Register a shape for inclusion in the BVH.

This function can only be used before build() is called

Definition at line 308 of file bvh.cpp.

rayIntersect()

bool BVH::rayIntersect	(	const Ray3f &	ray,
		Intersection &	its,
		bool	shadowRay = false
	)		const

Intersect a ray against all shapes registered with the BVH.

Detailed information about the intersection, if any, will be stored in the provided Intersection data record.

The shadowRay parameter specifies whether this detailed information is really needed. When set to true, the function just checks whether or not there is occlusion, but without providing any more detail (i.e. its will not be filled with contents). This is usually much faster.

Returns

true If an intersection was found

Definition at line 404 of file bvh.cpp.

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The documentation for this class was generated from the following files:

• bvh.h
• bvh.cpp