Encapsulates the limit surface for a face of a mesh. More...

#include <surface.h>

Classes
struct	PointDescriptor
	Simple struct defining the size and stride of points in arrays. More...

Public Types
typedef int	Index
	Integer type representing a mesh index.

Public Member Functions
Construction and initialization
Instances of Surface may be explicitly constructed, but are initialized by SurfaceFactory and so only default construction is provided. An instance will be invalid (and so unusable) if default constructed, or if the factory that initialized it determined that the face associated with it has no limit surface.
bool	IsValid () const
	Return true if successfully initialized.

void	Clear ()
	Clear a previously initialized Surface.

	Surface ()
	Default construction produces an invalid instance.

	Surface (Surface const &src)=default

Surface &	operator= (Surface const &src)=default

	~Surface ()=default

Simple queries
Simple queries of valid Surface.
Parameterization	GetParameterization () const
	Return the Parameterization.

int	GetFaceSize () const
	Return the size of the face.

bool	IsRegular () const
	Return if the Surface is a single regular patch.

bool	IsLinear () const
	Return if the Surface is linear.

Methods to manage control points
Control points are the subset of points in the mesh that influence a Surface. They can be identified as part of the mesh data by their indices, or gathered into an array for other purposes. It is not necessary to deal directly with control points for evaluation, but they are useful with limit stencils and other purposes, e.g. computing a bounding box of the control hull of the Surface. Note that methods that access control points from the array of mesh data require that the array be contiguous. If a large data set is fragmented into blocks or pages, these methods cannot be used and control points will need to be gathered explicitly.
int	GetNumControlPoints () const
	Return the number of control points affecting the Surface.

int	GetControlPointIndices (Index meshPointIndices[]) const
	Identify indices of control points in the mesh.

template<typename REAL_MESH >
void	GatherControlPoints (REAL_MESH const meshPoints[], PointDescriptor const &meshPointDesc, REAL controlPoints[], PointDescriptor const &controlPointDesc) const
	Gather control points in a local array.

void	BoundControlPoints (REAL const controlPoints[], PointDescriptor const &controlPointDesc, REAL minExtent[], REAL maxExtent[]) const
	Compute bounds of control points from a local array.

void	BoundControlPointsFromMesh (REAL const meshPoints[], PointDescriptor const &meshPointDesc, REAL minExtent[], REAL maxExtent[]) const
	Compute bounds of control points from the mesh data.

Methods to manage patch points
Patch points are derived from the control points and are used to evaluate the Surface. The patch points always include the control points as a subset.
int	GetNumPatchPoints () const
	Return the number of patch points representing the Surface.

void	PreparePatchPoints (REAL const meshPoints[], PointDescriptor const &meshPointDesc, REAL patchPoints[], PointDescriptor const &patchPointDesc) const
	Prepare patch points in a local array for evaluation.

void	ComputePatchPoints (REAL patchPoints[], PointDescriptor const &patchPointDesc) const
	Compute all patch points following the control points.

Evaluation of positions and derivatives
Evaluation methods use the patch points to compute position, 1st and 2nd derivatives of the Surface at a given (u,v) coordinate within the domain of the Surface's Parameterization. All parameters of the different overloads are required.
void	Evaluate (REAL const uv[2], REAL const patchPoints[], PointDescriptor const &pointDesc, REAL P[]) const
	Evaluation of position.

void	Evaluate (REAL const uv[2], REAL const patchPoints[], PointDescriptor const &pointDesc, REAL P[], REAL Du[], REAL Dv[]) const
	Overload of evaluation for 1st derivatives.

void	Evaluate (REAL const uv[2], REAL const patchPoints[], PointDescriptor const &pointDesc, REAL P[], REAL Du[], REAL Dv[], REAL Duu[], REAL Duv[], REAL Dvv[]) const
	Overload of evaluation for 2nd derivatives.

Evaluation and application of limit stencils
Limit stencils are sets of coefficients that express an evaluation as a linear combination of the control points. As with the direct evaluation methods, they are overloaded to optionally provide evaluation for 1st and 2nd derivatives. In addition to methods to provide limit stencils, methods are also provided to apply them to the control points. Since application of stencils is identical for each (i.e. the same for position and any derivative) no overloads are provided for derivatives.
class	SurfaceFactory

int	EvaluateStencil (REAL const uv[2], REAL sP[]) const
	Evaluation of the limit stencil for position.

int	EvaluateStencil (REAL const uv[2], REAL sP[], REAL sDu[], REAL sDv[]) const
	Overload of limit stencil evaluation for 1st derivatives.

int	EvaluateStencil (REAL const uv[2], REAL sP[], REAL sDu[], REAL sDv[], REAL sDuu[], REAL sDuv[], REAL sDvv[]) const
	Overload of limit stencil evaluation for 2nd derivatives.

void	ApplyStencil (REAL const stencil[], REAL const controlPoints[], PointDescriptor const &, REAL result[]) const
	Apply a single stencil to control points from a local array.

void	ApplyStencilFromMesh (REAL const stencil[], REAL const meshPoints[], PointDescriptor const &, REAL result[]) const
	Apply a single stencil to control points from the mesh data.

Detailed Description

template<typename REAL>
class OpenSubdiv::OPENSUBDIV_VERSION::Bfr::Surface< REAL >

Encapsulates the limit surface for a face of a mesh.

The Surface class encapsulates the limit surface for a face of a mesh for any data interpolation type (vertex, varying and face-varying) and provides the public interface for its evaluation. Surface is a class template parameterized to support evaluation in single or double precision.

Template Parameters

REAL	Floating point precision (float or double only)

Instances of Surface are created or initialized by a subclass of the SurfaceFactory. Since existing instances can be re-initialized, they should be tested for validity after such re-initialization.

All Surfaces are assigned a Parameterization based on the subdivision scheme and the size of the face, which can then be used for evaluation and tessellation of the surface.

Definition at line 59 of file surface.h.

Member Typedef Documentation

◆ Index

typedef int Index

Integer type representing a mesh index.

Definition at line 72 of file surface.h.

Constructor & Destructor Documentation

◆ Surface() [1/2]

Surface ( )

Default construction produces an invalid instance.

◆ Surface() [2/2]

Surface ( Surface< REAL > const & src )

default

◆ ~Surface()

~Surface ( )

default

Member Function Documentation

◆ ApplyStencil()

void ApplyStencil	(	REAL const	stencil[],
		REAL const	controlPoints[],
		PointDescriptor const &	,
		REAL	result[]
	)		const

Apply a single stencil to control points from a local array.

◆ ApplyStencilFromMesh()

void ApplyStencilFromMesh	(	REAL const	stencil[],
		REAL const	meshPoints[],
		PointDescriptor const &	,
		REAL	result[]
	)		const

Apply a single stencil to control points from the mesh data.

◆ BoundControlPoints()

void BoundControlPoints	(	REAL const	controlPoints[],
		PointDescriptor const &	controlPointDesc,
		REAL	minExtent[],
		REAL	maxExtent[]
	)		const

Compute bounds of control points from a local array.

◆ BoundControlPointsFromMesh()

void BoundControlPointsFromMesh	(	REAL const	meshPoints[],
		PointDescriptor const &	meshPointDesc,
		REAL	minExtent[],
		REAL	maxExtent[]
	)		const

Compute bounds of control points from the mesh data.

◆ Clear()

void Clear ( )

inline

Clear a previously initialized Surface.

Definition at line 89 of file surface.h.

◆ ComputePatchPoints()

void ComputePatchPoints	(	REAL	patchPoints[],
		PointDescriptor const &	patchPointDesc
	)		const

inline

Compute all patch points following the control points.

For cases where the control points have already been gathered into an array allocated for the patch points, the remaining patch points will be computed.

Parameters

patchPoints	Array of patch point data to be modified
patchPointDesc	The size and stride of patch point data

Definition at line 331 of file surface.h.

◆ Evaluate() [1/3]

void Evaluate	(	REAL const	uv[2],
		REAL const	patchPoints[],
		PointDescriptor const &	pointDesc,
		REAL	P[]
	)		const

inline

Evaluation of position.

Definition at line 372 of file surface.h.

◆ Evaluate() [2/3]

void Evaluate	(	REAL const	uv[2],
		REAL const	patchPoints[],
		PointDescriptor const &	pointDesc,
		REAL	P[],
		REAL	Du[],
		REAL	Dv[]
	)		const

inline

Overload of evaluation for 1st derivatives.

Definition at line 382 of file surface.h.

◆ Evaluate() [3/3]

void Evaluate	(	REAL const	uv[2],
		REAL const	patchPoints[],
		PointDescriptor const &	pointDesc,
		REAL	P[],
		REAL	Du[],
		REAL	Dv[],
		REAL	Duu[],
		REAL	Duv[],
		REAL	Dvv[]
	)		const

inline

Overload of evaluation for 2nd derivatives.

Definition at line 392 of file surface.h.

◆ EvaluateStencil() [1/3]

int EvaluateStencil	(	REAL const	uv[2],
		REAL	sP[]
	)		const

inline

Evaluation of the limit stencil for position.

Definition at line 416 of file surface.h.

◆ EvaluateStencil() [2/3]

int EvaluateStencil	(	REAL const	uv[2],
		REAL	sP[],
		REAL	sDu[],
		REAL	sDv[]
	)		const

inline

Overload of limit stencil evaluation for 1st derivatives.

Definition at line 423 of file surface.h.

◆ EvaluateStencil() [3/3]

int EvaluateStencil	(	REAL const	uv[2],
		REAL	sP[],
		REAL	sDu[],
		REAL	sDv[],
		REAL	sDuu[],
		REAL	sDuv[],
		REAL	sDvv[]
	)		const

inline

Overload of limit stencil evaluation for 2nd derivatives.

Definition at line 431 of file surface.h.

◆ GatherControlPoints()

void GatherControlPoints	(	REAL_MESH const	meshPoints[],
		PointDescriptor const &	meshPointDesc,
		REAL	controlPoints[],
		PointDescriptor const &	controlPointDesc
	)		const

Gather control points in a local array.

Template Parameters

REAL_MESH Floating point precision of mesh points

Parameters

meshPoints	Input array of mesh point data
meshPointDesc	The size and stride of mesh point data
controlPoints	Output array of control point data
controlPointDesc	The size and stride of control point data

◆ GetControlPointIndices()

int GetControlPointIndices ( Index meshPointIndices[] ) const

Identify indices of control points in the mesh.

◆ GetFaceSize()

int GetFaceSize ( ) const

inline

Return the size of the face.

Definition at line 109 of file surface.h.

◆ GetNumControlPoints()

int GetNumControlPoints ( ) const

inline

Return the number of control points affecting the Surface.

Definition at line 137 of file surface.h.

◆ GetNumPatchPoints()

int GetNumPatchPoints ( ) const

Return the number of patch points representing the Surface.

◆ GetParameterization()

Parameterization GetParameterization ( ) const

inline

Return the Parameterization.

Definition at line 106 of file surface.h.

◆ IsLinear()

bool IsLinear ( ) const

inline

Return if the Surface is linear.

Definition at line 115 of file surface.h.

◆ IsRegular()

bool IsRegular ( ) const

inline

Return if the Surface is a single regular patch.

Definition at line 112 of file surface.h.

◆ IsValid()

bool IsValid ( ) const

inline

Return true if successfully initialized.

Definition at line 86 of file surface.h.

◆ operator=()

Surface & operator= ( Surface< REAL > const & src )

default

◆ PreparePatchPoints()

void PreparePatchPoints	(	REAL const	meshPoints[],
		PointDescriptor const &	meshPointDesc,
		REAL	patchPoints[],
		PointDescriptor const &	patchPointDesc
	)		const

inline

Prepare patch points in a local array for evaluation.

The patch points consist of the control points plus any additional points derived from them that may be required to represent the limit surface as one or more parametric patches.

Parameters

meshPoints	Input array of mesh point data
meshPointDesc	The size and stride of mesh point data
patchPoints	Output array of patch point data
patchPointDesc	The size and stride of patch point data

Note that this method requires the mesh data be in a contiguous array. If a large data set is fragmented into blocks or pages, this method cannot be used. The control points will need to be gathered explicitly as the subset of patch points, after which the method to compute the remaining patch points can be used.

Definition at line 345 of file surface.h.

Friends And Related Function Documentation

◆ SurfaceFactory

friend class SurfaceFactory

friend

Definition at line 315 of file surface.h.

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

opensubdiv/bfr/surface.h

Classes

Public Types

Public Member Functions

Evaluation and application of limit stencils

Detailed Description

Member Typedef Documentation

◆ Index

Constructor & Destructor Documentation

◆ Surface() [1/2]

◆ Surface() [2/2]

◆ ~Surface()

Member Function Documentation

◆ ApplyStencil()

◆ ApplyStencilFromMesh()

◆ BoundControlPoints()

◆ BoundControlPointsFromMesh()

◆ Clear()

◆ ComputePatchPoints()

◆ Evaluate() [1/3]

◆ Evaluate() [2/3]

◆ Evaluate() [3/3]

◆ EvaluateStencil() [1/3]

◆ EvaluateStencil() [2/3]

◆ EvaluateStencil() [3/3]

◆ GatherControlPoints()

◆ GetControlPointIndices()

◆ GetFaceSize()

◆ GetNumControlPoints()

◆ GetNumPatchPoints()

◆ GetParameterization()

◆ IsLinear()

◆ IsRegular()

◆ IsValid()

◆ operator=()

◆ PreparePatchPoints()

Friends And Related Function Documentation

◆ SurfaceFactory