A FlatMeshSDF must be trivially copyable: that is what lets a rebasedView() be byte-copied into a device address space with no pointer patching. More...

#include <EBGeometry_MeshDistanceFunctions.hpp>

Inheritance diagram for EBGeometry::MeshSDF< T, K >:

[legend]

Collaboration diagram for EBGeometry::MeshSDF< T, K >:

[legend]

Classes
struct	Layout
	The object's arrays as offsets into its pool, with no location (see PoolHandle). More...

Public Types
using	Face = typename EBGeometry::DCEL::FaceT< T >
	Alias for DCEL face type.

using	Mesh = typename EBGeometry::DCEL::MeshT< T >
	Alias for DCEL mesh type.

using	Root = EBGeometry::BVH::PackedBVH< T, uint32_t, K >
	Alias for the linearized BVH root. Its primitives are face ids.

using	Node = typename Root::Node
	Alias for a single linearized node.

Public Member Functions
	MeshSDF ()=delete
	Default disallowed constructor.

	MeshSDF (const Layout &a_layout, const PoolLocation &a_location) noexcept
	Rebuild a handle from a stored layout and the location of the pool that holds it.

Layout	layout () const noexcept
	The object's arrays without its location, for storing it inside another pool-resident object.

	MeshSDF (const Mesh &a_mesh, Pool &a_pool, const BVH::Construction a_construction)
	Full constructor. Copies the mesh descriptor and builds the BVH over its faces.

	MeshSDF (const Mesh &a_mesh, Pool &a_pool, const BVH::Construction a_construction, const BVH::ConstructionOptions &a_options)
	Full constructor with leaf-size settings.

T	signedDistance (const Vec3T< T > &a_point) const noexcept
	Compute the signed distance from a_point to the mesh.

ClosestFace< T >	getClosestFace (const Vec3T< T > &a_point) const noexcept
	Find the face closest to a_point, and the signed distance to it.

Root	getRoot () const noexcept
	Get the PackedBVH enclosing the mesh.

Mesh	getMesh () const noexcept
	Get the DCEL mesh descriptor the BVH's faces resolve against.

EBGeometry::BoundingVolumes::AABBT< T >	computeBoundingVolume () const noexcept
	Compute the AABB enclosing the entire mesh.

MeshSDF	rebasedView (const Pool &a_pool) const noexcept
	Produce a copy of this object that resolves against `a_pool`.

MeshSDF	deepCopy (Pool &a_dstPool) const
	Duplicate the mesh's and the BVH's storage into `a_dstPool`.

Public Member Functions inherited from EBGeometry::PoolHandle
PoolLocation	location () const noexcept
	Where this handle's arrays live.

bool	isAttachedTo (const Pool &a_pool) const noexcept
	Check whether this handle's arrays were reserved from `a_pool`.

Static Public Member Functions
static BVH::ConstructionOptions	defaultConstructionOptions () noexcept
	The leaf-size settings the constructor without options uses.

Static Public Attributes
static constexpr DistanceQuality	distanceQuality = DistanceQuality::Exact
	How far signedDistance() can be trusted as a distance: the Euclidean distance to a watertight mesh.

Additional Inherited Members
Protected Member Functions inherited from EBGeometry::PoolHandle
	PoolHandle () noexcept=default
	An unset location; the first reservation attaches it.

	PoolHandle (const PoolLocation &a_location) noexcept
	Adopt a location, as a handle rebuilt from a stored layout does.

	PoolHandle (const PoolHandle &) noexcept=default
	Copy a handle, as a derived handle's copy does.

	PoolHandle (PoolHandle &&) noexcept=default
	Move a handle; the same as a copy.

PoolHandle &	operator= (const PoolHandle &) noexcept=default
	Copy-assign a handle, as a derived handle's assignment does.

PoolHandle &	operator= (PoolHandle &&) noexcept=default
	Move-assign a handle; the same as a copy.

	~PoolHandle () noexcept=default
	Destructor; protected, since a PoolHandle exists only as the base of a handle.

void *	base () noexcept
	The base address this handle's offsets resolve against; see PoolLocation::base().

const void *	base () const noexcept
	The base address this handle's offsets resolve against, for read-only access.

void	attach (const Pool &a_pool, const char *a_who) noexcept
	Follow `a_pool`, as the first reservation does; see PoolLocation::attach().

PoolLocation	rebasedLocation (const Pool &a_pool, uint64_t a_endByte, const char *a_who) const noexcept
	The location of this handle's arrays in another pool of its mirror chain; see PoolLocation::rebasedOnto().

void	setLocation (const PoolLocation &a_location) noexcept
	Replace the location, for a view or a copy made by a derived handle.

Detailed Description

template<class T, size_t K>
class EBGeometry::MeshSDF< T, K >

A FlatMeshSDF must be trivially copyable: that is what lets a rebasedView() be byte-copied into a device address space with no pointer patching.

Signed distance function for a DCEL mesh, accelerated by a PackedBVH over its faces. Accepts any polygon, not just triangles.

The BVH's primitives are face ids: indices into the mesh's face array, four bytes each. Every query resolves a face through the mesh, which MeshSDF holds as well, so the mesh is the only copy of the geometry: flipping the mesh (DCEL::MeshT::flip()) after building flips every distance, and after moving vertices, reconciling the mesh and refitting the BVH (see getRoot()) is enough. The price of four bytes per face rather than the 88 of a face copy is reading faces in mesh order rather than leaf order, which made queries on the armadillo (100k faces) about 15% slower than with copies, near the surface and away from it alike. SIMD node pruning is used when T and K match an available ISA path.

A plain value type, like FlatMeshSDF: it holds the mesh descriptor and the BVH by value, both resolving against the one Pool passed to the constructor, so it is trivially copyable and signedDistance() is callable on the host and on a device. It has no virtual functions: a class with them can never be passed to a kernel. Copies share the pool memory, and the pool must outlive all of them. To evaluate on a device, freeze and mirror the pool and pass rebasedView() into a kernel.

Template Parameters

T	Floating-point precision type (float or double).
K	BVH branching factor (number of children per internal node).

Constructor & Destructor Documentation

◆ MeshSDF() [1/3]

template<class T , size_t K>

EBGeometry::MeshSDF< T, K >::MeshSDF	(	const Layout &	a_layout,
		const PoolLocation &	a_location
	)

inlinenoexcept

Rebuild a handle from a stored layout and the location of the pool that holds it.

How an outer pool-resident object, such as a BVHUnion, evaluates a MeshSDF it stores as a layout. a_location must belong to the pool the layout was reserved from, or to a mirror of it; nothing is checked, since a device has no pool to check against.

Parameters

[in]	a_layout	The arrays.
[in]	a_location	Where they live.

◆ MeshSDF() [2/3]

template<class T , size_t K>

EBGeometry::MeshSDF< T, K >::MeshSDF	(	const Mesh &	a_mesh,
		Pool &	a_pool,
		const BVH::Construction	a_construction
	)

inline

Full constructor. Copies the mesh descriptor and builds the BVH over its faces.

No default arguments: this is a low-level constructor, and callers working at this level must consciously choose a construction method. Use Parser::readIntoMeshSDF for sensible defaults. The BVH is reserved from a_pool, which must be the pool a_mesh was built in, so that one rebasedView() rebases both. a_pool must outlive this object and every copy of it.

Parameters

[in]	a_mesh	Input mesh, built against a_pool.
[in,out]	a_pool	Pool a_mesh's storage was reserved from; the BVH is reserved here too.
[in]	a_construction	Preset construction method; every BVH::Construction value is supported. SAH (binned Surface Area Heuristic) is recommended. The leaf sizes are defaultConstructionOptions(): the top-down methods stop at fewer than K faces per leaf, and ClusterSAH uses the default ClusterSpec, so a leaf holds up to (K-1) clusters of faces.

◆ MeshSDF() [3/3]

template<class T , size_t K>

EBGeometry::MeshSDF< T, K >::MeshSDF	(	const Mesh &	a_mesh,
		Pool &	a_pool,
		const BVH::Construction	a_construction,
		const BVH::ConstructionOptions &	a_options
	)

inline

Full constructor with leaf-size settings.

As the constructor without options, which uses defaultConstructionOptions(). The chosen method reads only its own field of a_options; see BVH::ConstructionOptions.

Parameters

[in]	a_mesh	Input mesh, built against a_pool.
[in,out]	a_pool	Pool a_mesh's storage was reserved from; the BVH is reserved here too.
[in]	a_construction	Preset construction method; every BVH::Construction value is supported.
[in]	a_options	Leaf-size settings, in faces.

Member Function Documentation

◆ computeBoundingVolume()

template<class T , size_t K>

EBGeometry::BoundingVolumes::AABBT< T > EBGeometry::MeshSDF< T, K >::computeBoundingVolume ( ) const

inlinenoexcept

Compute the AABB enclosing the entire mesh.

Returns: Axis-aligned bounding box of the mesh.

◆ deepCopy()

template<class T , size_t K>

MeshSDF EBGeometry::MeshSDF< T, K >::deepCopy ( Pool & a_dstPool ) const

inline

Duplicate the mesh's and the BVH's storage into a_dstPool.

The copy constructor copies descriptors only. This gives genuinely independent storage. The copied face ids still name the right faces of the copied mesh, since a mesh deep copy preserves every element's index.

Parameters

[in,out] a_dstPool Pool to reserve the copy from; may be this object's own pool.

Returns: A MeshSDF over independent copies of the mesh and BVH, attached to a_dstPool.

◆ defaultConstructionOptions()

template<class T , size_t K>

static BVH::ConstructionOptions EBGeometry::MeshSDF< T, K >::defaultConstructionOptions ( )

inlinestaticnoexcept

The leaf-size settings the constructor without options uses.

K-1 faces per leaf for the top-down methods (a node with fewer than K faces is a leaf), a target of 1 for the space-filling curves (the deepest balanced tree, at most K faces per leaf), and the default ClusterSpec for ClusterSAH. Start from these to change one method's setting; see BVH::ConstructionOptions.

Returns: The default settings.

◆ getClosestFace()

template<class T , size_t K>

ClosestFace< T > EBGeometry::MeshSDF< T, K >::getClosestFace ( const Vec3T< T > & a_point ) const

inlinenoexcept

Find the face closest to a_point, and the signed distance to it.

The same BVH traversal as signedDistance() (PackedBVH::traverse() with a PointQuery), keeping the winning face's id as well, so it is callable on a device too.

Parameters

[in] a_point Query point. Must be finite.

Returns: The closest face's id (its index in the mesh) and signed distance. The signed distance equals what signedDistance() returns for the same point.

◆ getMesh()

template<class T , size_t K>

Mesh EBGeometry::MeshSDF< T, K >::getMesh ( ) const

inlinenoexcept

Get the DCEL mesh descriptor the BVH's faces resolve against.

Returns: The mesh.

◆ getRoot()

template<class T , size_t K>

Root EBGeometry::MeshSDF< T, K >::getRoot ( ) const

inlinenoexcept

Get the PackedBVH enclosing the mesh.

Mutable, so that PackedBVH::refit() can be called on it. After moving the mesh's vertices, reconcile the mesh (DCEL::MeshT::reconcile()), which recomputes its normals, then refit with each face's new bounding box:

sdf.getRoot().refit([&mesh](uint32_t a_face) {
  return BoundingVolumes::AABBT<T>(mesh.getFace(a_face).getAllVertexCoordinates(mesh));
});

This is enough because the BVH stores face ids and reads the faces from the mesh. A deformation large enough to degrade the tree still calls for a rebuild.

Returns: The packed BVH.

◆ layout()

template<class T , size_t K>

Layout EBGeometry::MeshSDF< T, K >::layout ( ) const

inlinenoexcept

The object's arrays without its location, for storing it inside another pool-resident object.

Returns: The layout.

◆ rebasedView()

template<class T , size_t K>

MeshSDF EBGeometry::MeshSDF< T, K >::rebasedView ( const Pool & a_pool ) const

inlinenoexcept

Produce a copy of this object that resolves against a_pool.

Rebases the mesh descriptor and the BVH together; see DCEL::MeshT::rebasedView() and BVH::PackedBVH::rebasedView() for the contract. This is the one sanctioned crossing to a device.

Parameters

[in] a_pool Pool to rebase onto: the object's own pool or one in its mirror chain.

Returns: A MeshSDF resolving against a_pool.

◆ signedDistance()

template<class T , size_t K>

T EBGeometry::MeshSDF< T, K >::signedDistance ( const Vec3T< T > & a_point ) const

inlinenoexcept

Compute the signed distance from a_point to the mesh.

Parameters

[in] a_point Query point.

Returns: Signed distance to the nearest face; negative inside the mesh.

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

Source/EBGeometry_MeshDistanceFunctions.hpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MeshSDF() [1/3]

◆ MeshSDF() [2/3]

◆ MeshSDF() [3/3]

Member Function Documentation

◆ computeBoundingVolume()

◆ deepCopy()

◆ defaultConstructionOptions()

◆ getClosestFace()

◆ getMesh()

◆ getRoot()

◆ layout()

◆ rebasedView()

◆ signedDistance()