# MFnNurbsSurface Class ReferenceOpenMaya - API module for common classes | FunctionSet classes

This reference page is linked to from the following overview topics: Maya Architecture Overview, Objects and Function Sets, Transforms and shapes, A more complex example, Threading and Maya, Overview of example plug-ins, Appendix D: Frequently asked questions.

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## Detailed Description

NURBS surface function set.

This is the function set for NURBS (Non-Uniform Rational B-spline) surfaces.

The shape of a NURBS surface is defined by an array of CVs (control vertices), an array of knot values in the U direction and an array of knot values in the V direction, a degree in U and in V, and a form in U and in V.

The U and V knot vectors for NURBS surfaces are of size (spansInU + 2*degreeInU -1) and (spansInV + 2*degreeInV -1). Note: spans = numCVs - degree.

There are 3 possible "forms" for the surface in the U and V directions: open, closed and periodic. These forms are described below. Note that the descriptions below apply to both the U and V directions.

The open and closed forms are quite similar, and in fact a closed surface will become and open surface if either the first or last CV is moved so that they are no longer coincident. To create an open or closed surface, of degree N, with M spans, you must provide M+N CVs. This implies that for a degree N surface, you must specify at least N+1 CVs to get a surface with a single span.

The number of knots required for the surface is M + 2N - 1. If you want the surface to start exactly at the first CV and end exactly at the last CV, then the knot vector must be structured to have degree N "multiplicity" at the beginning and end. This means that the first N knots must be identical, and the last N knots must be identical.

A periodic surface is a special case of a closed surface. Instead of having just the first and last CVs coincident, the last N CVs in the surface, where N is equal to the degree, overlap the first N CVs. This results in a surface with no tangent break where the ends meet. The last N CVs in a periodic surface are permanently bound to the first N CVs, and Maya will not allow those last N CVs to be repositioned. If one or more of the first N CVs of the surface are repositioned, the overlapping CV's will remain bound, and will also be moved.

In order to create a periodic surface, you must specify at least 2N+1 CVs, so that that last N can overlap the first N and you still have 1 non-overlapping CV left. The number of CVs required to create a periodic surface is still N+M (with a lower limit of 2N+1), but you must ensure that the positions of the last N CVs are identical to the positions of the first N.

You still need M + 2N - 1 knots for a periodic surface, but the knot values required are more restrictive than for open or closed surfaces because of the overlap of the last N CVs. The first N knots should be specified at the beginning of the knot array as values { -(N-1), -(N-2), ... 0 } in order to implement the overlap. Additionally there can be no knot multiplicity at the end of the surface, because that would compromise the tangent continuity property.

Managing different knot representations in external applications

Note that some third party applications use a different format for knots, where the number of knots required for a surface is M+2N+1 rather than M+2N-1 as used in Maya. Both knot representations are equivalent mathematically. To convert from one of these external representations into the Maya representation, simply omit the first and last knots from the external representation when creating the Maya representation. To convert from the Maya representation into the external representation, add two new knots at the beginning and end of the Maya knot sequence. The value of these new knots depends on the existing knot sequence. For a knot sequence with multiple end knots, simply duplicate the existing first and last knots once more, for example:

Maya representation: {0,0,0,...,N,N,N} External representation: {0,0,0,0,...,N,N,N,N}

For a knot sequence with uniform end knots, create the new knots offset at an interval equal to the existing first and last knot intervals, for example:

Maya representation: {0,1,2,...,N,N+1,N+2} External representation: {-1,0,1,2,...,N,N+1,N+2,N+3}

Examples:

`#include <MFnNurbsSurface.h>`

Inheritance diagram for MFnNurbsSurface:
[legend]

List of all members.

## Public Types

enum  Form {
kInvalid = 0, kOpen, kClosed, kPeriodic,
kLast
}

Forms that a surface may take in a given parametric direction.

More...
enum  BoundaryType {
kInvalidBoundary = 0, kOuter, kInner, kSegment,
kClosedSegment
}

Boundary types for trimmed surfaces.

More...

## Public Member Functions

virtual MFn::Type type () const
Function set type.
virtual ~MFnNurbsSurface ()
Destructor.
MFnNurbsSurface ()
Default constructor.
MFnNurbsSurface (MObject &object, MStatus *ReturnStatus=NULL)
Constructor.
MFnNurbsSurface (const MDagPath &object, MStatus *ret=NULL)
Constructor.
MObject create (const MPointArray &controlVertices, const MDoubleArray &uKnotSequences, const MDoubleArray &vKnotSequences, unsigned int degreeInU, unsigned int degreeInV, Form formU, Form formV, bool createRational, MObject parentOrOwner=MObject::kNullObj, MStatus *ReturnStatus=NULL)
Creates a nurbs surface from the specified data and sets this function set to operate on the new surface.
MObject copy (const MObject &source, MObject parentOrOwner=MObject::kNullObj, MStatus *ReturnStatus=NULL)
This method creates a copy of a nurbs surface.
MObject cv (unsigned int indexU, unsigned int indexV, MStatus *ReturnStatus=NULL)
Returns a component for the specified CV.
MObject cvsInU (unsigned int startIndex, unsigned int endIndex, unsigned int rowIndex, MStatus *ReturnStatus=NULL)
Returns a component for the specified CVs.
MObject cvsInV (unsigned int startIndex, unsigned int endIndex, unsigned int rowIndex, MStatus *ReturnStatus=NULL)
Returns a component for the specified CVs on the given V direction.
MStatus getCVs (MPointArray &array, MSpace::Space space=MSpace::kObject) const
Get the positions of the CVs on this surface.
MStatus setCVs (const MPointArray &array, MSpace::Space space=MSpace::kObject)
Set the CVs for this surface to the given points.
MStatus getCV (unsigned int indexU, unsigned int indexV, MPoint &pnt, MSpace::Space space=MSpace::kObject) const
Get the location of the specified CV.
MStatus setCV (unsigned int indexU, unsigned int indexV, MPoint &pnt, MSpace::Space space=MSpace::kObject) const
Set the location of the specified CV.
Form formInU (MStatus *ReturnStatus=NULL) const
Return the form of this surface in U.
Form formInV (MStatus *ReturnStatus=NULL) const
Return the form of this surface in V.
bool isBezier (MStatus *ReturnStatus=NULL) const
Determine if the knot spacing gives us Bezier surface.
bool isUniform (MStatus *ReturnStatus=NULL) const
Determine if the knot spacing is uniform.
bool isKnotU (double param, MStatus *ReturnStatus=NULL) const
Check if the specified parameter value is a knot value.
bool isKnotV (double param, MStatus *ReturnStatus=NULL) const
Check if the specified parameter value is a knot value.
bool isParamOnSurface (double paramU, double paramV, MStatus *ReturnStatus=NULL) const
Check if the specified parameter is on this surface.
MStatus getKnotDomain (double &startU, double &endU, double &startV, double &endV) const
Returns the maximum and minimum U and V paramter values for this surface.
int degreeU (MStatus *ReturnStatus=NULL) const
Returns the degree of the surface in U (1 - 3).
int degreeV (MStatus *ReturnStatus=NULL) const
Returns the degree of the surface in V (1 - 3).
int numSpansInU (MStatus *ReturnStatus=NULL) const
Returns the number of spans in the u direction.
int numSpansInV (MStatus *ReturnStatus=NULL) const
Returns the number of spans in the v direction.
int numNonZeroSpansInU (MStatus *ReturnStatus=NULL) const
Returns the number of non-zero spans in the U direction.
int numNonZeroSpansInV (MStatus *ReturnStatus=NULL) const
Returns the number of non-zero spans in the V direction.
int numCVsInU (MStatus *ReturnStatus=NULL) const
Returns the number of CVs in the U direction (degree + spans).
int numCVsInV (MStatus *ReturnStatus=NULL) const
Returns the number of CVs in the V direction (degree + spans).
int numKnotsInU (MStatus *ReturnStatus=NULL) const
Returns the number of knots in U including multiple end knots (spans + 2 * degree - 1).
int numKnotsInV (MStatus *ReturnStatus=NULL) const
Returns the number of knots in V including multiple end knots (spans + 2 * degree - 1).
MStatus getKnotsInU (MDoubleArray &array) const
Get the knots along the U direction for this surface.
MStatus getKnotsInV (MDoubleArray &array) const
Get the knots along the V direction for this surface.
MStatus setKnotsInU (const MDoubleArray &array, unsigned int startIndex, unsigned int endIndex)
Set the specified U knot values for this surface.
MStatus setKnotsInV (const MDoubleArray &array, unsigned int startIndex, unsigned int endIndex)
Set the specified V knot values for this surface.
double knotInU (unsigned int index, MStatus *ReturnStatus=NULL) const
Retrieve the given knot value from this surface at the specified U index.
double knotInV (unsigned int index, MStatus *ReturnStatus=NULL) const
Retrieve the given knot value from this surface at the specified V index.
MStatus setKnotInU (unsigned int index, double param)
Set the value of the given existing knot at the specified U index.
MStatus setKnotInV (unsigned int index, double param)
Set the value of the given existing knot at the specified V index.
MStatus removeKnotInU (double atThisParam, bool removeAll=false)
Remove the U knot(s) at the specified parameter value from this surface.
MStatus removeKnotInV (double atThisParam, bool removeAll=false)
Remove the V knot(s) at the specified parameter value from this surface.
MStatus removeOneKnotInU (double atThisParam)
Remove one U knot at the specified parameter value from this surface.
MStatus removeOneKnotInV (double atThisParam)
Remove one V knot at the specified parameter value from this surface.
MVector normal (double paramInU, double paramInV, MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
Retrieve the normal at the given parameter value on the surface.
MStatus getTangents (double paramInU, double paramInV, MVector &vectorInU, MVector &vectorInV, MSpace::Space space=MSpace::kObject) const
Retrieve the tangents in the U and V directions at the given parameter value on the surface.
MStatus getDerivativesAtParm (double paramInU, double paramInV, MPoint &pos, MVector &dU, MVector &dV, MSpace::Space space, MVector *dUU=NULL, MVector *dVV=NULL, MVector *dUV=NULL) const
Evaluate the surface at the given (u,v) coordinate returning position, first derivatives and optionally second derivative information.
bool isFoldedOnBispan () const
Evaluate the surface to determine if it contains any folds or creases.
double area (double tolerance=kMFnNurbsEpsilon, MStatus *ReturnStatus=NULL) const
Calculates the surface area of this nurbs surface.
double area (MSpace::Space space, double tolerance=kMFnNurbsEpsilon, MStatus *ReturnStatus=NULL) const
Calculates the surface area of this nurbs surface in world or local space.
MPoint closestPoint (const MPoint &toThisPoint, double *paramU=NULL, double *paramV=NULL, bool ignoreTrimBoundaries=false, double tolerance=kMFnNurbsEpsilon, MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
Return the closest point on this surface to the given point.
MPoint closestPoint (const MPoint &toThisPoint, bool paramAsStart, double *paramU, double *paramV, bool ignoreTrimBoundaries=false, double tolerance=kMFnNurbsEpsilon, MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
Return the closest point on this surface to the given point.
bool isPointOnSurface (const MPoint &point, double tolerance=kMFnNurbsEpsilon, MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
Check if the given point is on this surface.
MStatus getParamAtPoint (const MPoint &atThisPoint, double &paramU, double &paramV, MSpace::Space space=MSpace::kObject) const
This method is obsolete.
MStatus getParamAtPoint (const MPoint &atThisPoint, double &paramU, double &paramV, bool ignoreTrimBoundaries, MSpace::Space space=MSpace::kObject, double tolerance=kMFnNurbsEpsilon) const
Get the parameter value corresponding to the given point on the surface (or underlying surface).
MStatus getPointAtParam (double paramU, double paramV, MPoint &point, MSpace::Space space=MSpace::kObject) const
Finds the point corresponding to the given parameter value on the surface.
double distanceToPoint (const MPoint &pt, MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
Returns the distance from the given point to the closest point on the surface.
MObject tesselate (MTesselationParams &parms=MTesselationParams::fsDefaultTesselationParams, MObject parentOrOwner=MObject::kNullObj, MStatus *ReturnStatus=NULL)
Performs tesselation on this surface and create a new mesh in the DAG.
bool intersect (const MPoint &rayStartingPoint, const MVector &alongThisDirection, double &u, double &v, MPoint &intersectionData, double tolerance=kMFnNurbsEpsilon, MSpace::Space space=MSpace::kObject, bool calculateDistance=false, double *distance=NULL, bool calculateExactHit=false, bool *wasExactHit=NULL, MStatus *ReturnStatus=NULL) const
This function determines the closest point of intersection of this spline surface with a ray (a vector at a point).
bool intersect (const MPoint &rayStartingPoint, const MVector &alongThisDirection, MDoubleArray &u, MDoubleArray &v, MPointArray &intersectionData, double tolerance=kMFnNurbsEpsilon, MSpace::Space space=MSpace::kObject, bool calculateDistance=false, MDoubleArray *distances=NULL, bool calculateExactHit=false, bool *wasExactHit=NULL, MStatus *ReturnStatus=NULL) const
This function determines all the points of intersection of this spline surface with a ray (a vector at a point).
bool hasHistoryOnCreate (MStatus *ReturnStatus=NULL)
This method determines if the shape was created with history.
This method signals that this surface has changed and needs to be recalculated.
bool isTrimmedSurface (MStatus *ReturnStatus=NULL)
This method determines if this surface is a trimmed surface.
unsigned int numRegions (MStatus *ReturnStatus=NULL)
Returns the number of trimmed regions for this surface or 0 if the surface is not a trimmed surface.
bool isFlipNorm (unsigned int region, MStatus *ReturnStatus=NULL)
Determines whether the normal for the specified region is flipped.
unsigned int numBoundaries (unsigned int region, MStatus *ReturnStatus=NULL)
Returns the number of boudaries for the specified region.
BoundaryType boundaryType (unsigned int region, unsigned int boundary, MStatus *ReturnStatus=NULL)
Returns the type of the specified boundary.
unsigned int numEdges (unsigned int region, unsigned int boundary, MStatus *ReturnStatus=NULL)
Return the number of edges for the specified trim boundary.
MObjectArray edge (unsigned int region, unsigned int boundary, unsigned int edge, bool paramEdge=false, MStatus *ReturnStatus=NULL)
Return the specified edge of a trim boundary.
bool isPointInTrimmedRegion (double u, double v, MStatus *ReturnStatus=NULL)
Returns true if the given point is in a trimmed away region of a trimmed surface.
MStatus getTrimBoundaries (MTrimBoundaryArray &result, unsigned int region, bool paramEdge=true)
Returns all trim boundaries of a region on this surface.
MStatus trimWithBoundaries (const MTrimBoundaryArray &mBoundaries, bool flipNormal=false, double e_tol=1e-3, double pe_tol=1e-5, bool createNewRegion=false)
This function trims this surface with given trim boundaries.
MStatus projectCurve (MDagPath &curve, MVector *direction=NULL, bool constructionHistory=false)
Project the given curve onto this surface creating a curve on surface.
MStatus trim (MDoubleArray &locatorU, MDoubleArray &locatorV, bool constructionHistory=false)
Trim this surface to its curves on surface.
unsigned int numPatches (MStatus *ReturnStatus=NULL) const
Returns the number of non-zero patches in this surface.
unsigned int numPatchesInU (MStatus *ReturnStatus=NULL) const
Returns the number of non-zero patches along u, in this surface.
unsigned int numPatchesInV (MStatus *ReturnStatus=NULL) const
Returns the number of non-zero patches along v, in this surface.
int numUVs (MStatus *ReturnStatus=NULL) const
Returns the number of texture (uv) coordinates for this surface.
MStatus setUVs (const MFloatArray &uArray, const MFloatArray &vArray)
Sets all of the texture coordinates (uvs) for this surface.
MStatus getUVs (MFloatArray &uArray, MFloatArray &vArray) const
This method copies the texture coordinate list for this surface into the given uv arrays.
MStatus setUV (int uvId, float u, float v)
Sets the specified texture coordinate.
MStatus getUV (int uvId, float &u, float &v) const
Get the value of the specified texture coordinate from this surface's uv list.
MStatus getPatchUV (int patchId, int cornerIndex, float &u, float &v) const
Get the value of the specified texture coordinate for a patch corner in a patch.
MStatus getPatchUVs (int patchId, MFloatArray &uArray, MFloatArray &vArray) const
Get the values of the texture coordinate on a specified patch.
MStatus getPatchUVid (int patchId, int cornerIndex, int &uvId) const
Get the id of the specified texture coordinate for a corner in a patch.
MStatus assignUV (int patchId, int cornerIndex, int uvId)
Maps a texture coordinate to a the specified corner of a patch.
MStatus assignUVs (const MIntArray &uvCounts, const MIntArray &uvIds)
This method maps all texture coordinates for the surface.
MStatus clearUVs ()
This method clears out all texture coordinates for the nurbsSurface, and leaves behind an empty UVset.
MStatus getAssignedUVs (MIntArray &uvCounts, MIntArray &uvIds) const
Get assigned UVs.
MObject tesselate (MTesselationParams &parms, MStatus *ReturnStatus)
This method is obsolete.
MObject getDataObject () const
Returns an MObject if the class has been constructed with an MFn::kNurbsSurfaceData entity, otherwise MObject::kNullObj is returned.
MFnNurbsSurface (const MObject &object, MStatus *ret=NULL)
Constructor.

## Protected Member Functions

virtual const char * className () const
Class name.

## Member Enumeration Documentation

 enum Form

Forms that a surface may take in a given parametric direction.

Enumerator:
 kInvalid Search for all occurrences kOpen Edges are independent. Search for all occurrences kClosed Edges are coincident. Search for all occurrences kPeriodic Edges overlap such that there is no break in tangency. Search for all occurrences kLast Search for all occurrences
 enum BoundaryType

Boundary types for trimmed surfaces.

Enumerator:
 kInvalidBoundary Search for all occurrences kOuter Outer boundary, counter clockwise. Search for all occurrences kInner Inner boundary, clockwise. Search for all occurrences kSegment Curve on a face. Search for all occurrences kClosedSegment Closed curve on a face. Search for all occurrences

## Constructor & Destructor Documentation

 MFnNurbsSurface ( MObject & object, MStatus * ReturnStatus = `NULL` )

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters:
 [in] object The MObject to attach the function set to [out] ReturnStatus the return status
Status Codes:
 MFnNurbsSurface ( const MDagPath & object, MStatus * ReturnStatus = `NULL` )

Constructor.

Class constructor that initializes the function set to the given constant MDagPath object.

Parameters:
 [in] object The const MDagPath to attach the function set to [out] ReturnStatus The return status
Status Codes:
 MFnNurbsSurface ( const MObject & object, MStatus * ReturnStatus = `NULL` )

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters:
 [in] object The MObject to attach the function set to [out] ReturnStatus the return status
Status Codes:

## Member Function Documentation

 MFn::Type type ( ) const` [virtual]`

Function set type.

Return the class type : MFn::kNurbsSurface.

Reimplemented from MFnDagNode.

 const char * className ( ) const` [protected, virtual]`

Class name.

Return the class name : "MFnNurbsSurface".

Reimplemented from MFnDagNode.

 MObject create ( const MPointArray & controlVertices, const MDoubleArray & uKnotSequences, const MDoubleArray & vKnotSequences, unsigned int degreeInU, unsigned int degreeInV, MFnNurbsSurface::Form formU, MFnNurbsSurface::Form formV, bool createRational, MObject parentOrOwner = `MObject::kNullObj`, MStatus * ReturnStatus = `NULL` )

Creates a nurbs surface from the specified data and sets this function set to operate on the new surface.

The parentOrOwner argument is used to specify the owner of the new surface.

If the parentOrOwner is kNurbsSurfaceData then the created surface will be of type kNurbsSurfaceGeom and will be returned. The parentOrOwner will become the owner of the new surface.

If parentOrOwner is NULL then a new transform will be created and returned which will be the parent for the surface. The new transform will be added to the DAG.

If parentOrOwner is a DAG node then the new surface will be returned and the parentOrOwner will become its parent.

Note that the knot vectors must be of length spans + 2*degree - 1.

Parameters:
 [in] controlVertices an array of control vertices [in] uKnotSequences an array of U knot values [in] vKnotSequences an array of V knot values [in] degreeInU degree of first set of basis functions [in] degreeInV degree of second set of basis functions [in] formU open, closed, periodic in U [in] formV open, closed, periodic in V [in] createRational create as rational (true) or non-rational (false) surface [in] parentOrOwner specifies what to do with the surface. If a DAG object or NULL is given then a transform will be created for the new surface and placed under the specified (optional)parent. If kNurbsSurfaceData is given then the surface will become its data. [out] ReturnStatus Status code
Returns:
• If parentOrOwner is NULL then the transform for this surface is returned
• If parentOrOwner is a DAG object then the new surface shape is returned
• The surface geometry is returned if parentOrOwner is of type kNurbsSurfaceData
Status Codes:
• MS::kSuccess The method was successful.
• MS::kInvalidParameter Invalid parameters were specified.
• MS::kInsufficientMemory No memory available.
• MS::kFailure An object error has occurred.
• MS::kInvalidForm Form was not one of the MFnNurbsSurface::Form types
• MS::kInvalidNumberOfCVs Number of CVs doesn't match the number of knots. The number of CVs must be (numberOfUSpans+degreeInU)*(numberOfVSpans+degreeInV)
• MS::kInvalidNumberOfKnots Number of knots in one direction is zero.
• MS::kNotEnoughSpans Number of spans in one direction is zero. It should be (numberOfKnotsInU-(2*degreeInU)+1) or (numberOfKnotsInV-(2*degreeInV)+1)
• MS::kDecreasingKnots Knot vector was found to be decreasing. eg. (0,0,0,1,1,0.9) It should be non-decreasing, ie. same or increasing is okay, eg. (0,0,0,1,1,1.1)
• MS::kKnotMultiplicityTooHigh Knot vector has more than more than "degree" knots that are the same. It should have at most "degree" knots that are the same.
Examples:
fullLoftNode.cpp, simpleLoftNode.cpp, and surfaceCreateCmd.cpp.
 MObject copy ( const MObject & source, MObject parentOrOwner = `MObject::kNullObj`, MStatus * ReturnStatus = `NULL` )

This method creates a copy of a nurbs surface.

The parentOrOwner argument is used to specify the owner of the new surface.

If the parentOrOwner is kNurbsSurfaceData then the created surface will be of type kNurbsSurfaceGeom and will be returned. The parentOrOwner will become the owner of the new surface.

If parentOrOwner is NULL then a new transform will be created and returned which will be the parent for the surface. The new transform will be added to the DAG.

If parentOrOwner is a DAG node then the new surface will be returned and the parentOrOwner will become its parent.

Parameters:
 [in] source the surface to be copied [in] parentOrOwner the DAG parent or kNurbsSurfaceData the new surface will belong to [out] ReturnStatus Status code
Returns:
• If parentOrOwner is NULL then the transform for this surface is returned
• If parentOrOwner is a DAG object then the new surface shape is returned
• The surface geometry is returned if parentOrOwner is of type kNurbsSurfaceData
Status Codes:
 MObject cv ( unsigned int indexU, unsigned int indexV, MStatus * ReturnStatus = `NULL` )

Returns a component for the specified CV.

Components are used to specify one or more CVs and are usefull in operating on groups of non-contiguous CVs for a curve or surface. Components do not contain any information about the surface that they refer to so an MDagPath must be specified when dealing with components.

Parameters:
 [in] indexU U index of CV [in] indexV V index of CV [out] ReturnStatus Status code
Returns:
The cv component
Status Codes:
 MObject cvsInU ( unsigned int startIndex, unsigned int endIndex, unsigned int rowIndex, MStatus * ReturnStatus = `NULL` )

Returns a component for the specified CVs.

Components are used to specify one or more CVs and are usefull in operating on groups of non-contiguous CVs for a curve or surface. Components do not contain any information about the surface that they refer to so an MDagPath must be specified when dealing with components.

Parameters:
 [in] startIndex start CV index in U [in] endIndex end CV index in U [in] rowIndex row index [out] ReturnStatus Status code
Returns:
The component for the CVs on the given U direction.
Status Codes:
 MObject cvsInV ( unsigned int startIndex, unsigned int endIndex, unsigned int rowIndex, MStatus * ReturnStatus = `NULL` )

Returns a component for the specified CVs on the given V direction.

Components are used to specify one or more CVs and are usefull in operating on groups of non-contiguous CVs for a curve or surface. Components do not contain any information about the surface that they refer to so an MDagPath must be specified when dealing with components.

Parameters:
 [in] startIndex start CV index in V [in] endIndex end CV index in V [in] rowIndex row index [out] ReturnStatus Status code
Returns:
The component for the CVs
Status Codes:
 MStatus getCVs ( MPointArray & array, MSpace::Space space = `MSpace::kObject` ) const

Get the positions of the CVs on this surface.

The returned group can be accessed via the MPointArray class. numCVsInU() * numCVsInV() points will be returned. Converting from uIndex, vIndex is done by "index = numCVsInV() * uIndex + vIndex".

Any modifications to these CVs will not affect this surface. setCVs should be called to modify the original surface. updateSurface should be called to cause the surface to redraw itself.

Parameters:
 [out] array the array of point values for the CVs [in] space specifies the coordinate system for this operation
Returns:
 MStatus setCVs ( const MPointArray & array, MSpace::Space space = `MSpace::kObject` )

Set the CVs for this surface to the given points.

numCVsInU() * numCVsInV() points must be provided. Converting from uIndex, vIndex is done by "index = numCVsInV() * uIndex + vIndex".

To keep this method as fast as possible, no checking of the data is performed beyond ensuring that the total number of CVs passed in is correct. It is up to the caller to ensure that the CVs provide a valid surface, for example by ensuring that overlapping CVs in periodic surfaces have the same positions.

Parameters:
 [in] array The array of point values of the CVs [in] space specifies the coordinate system for this operation
Returns:
 MStatus getCV ( unsigned int indexU, unsigned int indexV, MPoint & pnt, MSpace::Space space = `MSpace::kObject` ) const

Get the location of the specified CV.

Parameters:
 [in] indexU U index of CV [in] indexV V index of CV [out] pnt storage for the CV location [in] space coordinate space for the CV
Returns:
 MStatus setCV ( unsigned int indexU, unsigned int indexV, MPoint & pt, MSpace::Space space = `MSpace::kObject` ) const

Set the location of the specified CV.

If the surface is periodic then overlapping CVs will be ignored, that is, only indices in U and V that are less that the number of spans in U and V respectively will be considered.

Parameters:
 [in] indexU U index of CV [in] indexV V index of CV [in] pt new location for the CV [in] space coordinate space for the CV
Returns:
 MFnNurbsSurface::Form formInU ( MStatus * ReturnStatus = `NULL` ) const

Return the form of this surface in U.

Form can be kOpen, kClosed, kPeriodic, or kUnknownForm.

Parameters:
 [out] ReturnStatus Status code
Returns:
The form of this surface in U
Status Codes:
 MFnNurbsSurface::Form formInV ( MStatus * ReturnStatus = `NULL` ) const

Return the form of this surface in V.

Form can be kOpen, kClosed, kPeriodic, or kUnknownForm.

Parameters:
 [out] ReturnStatus Status code
Returns:
The form of this surface in V
Status Codes:
 bool isBezier ( MStatus * ReturnStatus = `NULL` ) const

Determine if the knot spacing gives us Bezier surface.

Parameters:
 [out] ReturnStatus Status code
Returns:
• true Bezier surface
• false B-spline surface
Status Codes:
 bool isUniform ( MStatus * ReturnStatus = `NULL` ) const

Determine if the knot spacing is uniform.

Parameters:
 [out] ReturnStatus Status code
Returns:
• true Uniform knot spacing
• false Non-uniform knot spacing
Status Codes:
 bool isKnotU ( double param, MStatus * ReturnStatus = `NULL` ) const

Check if the specified parameter value is a knot value.

Parameters:
 [in] param parameter value to test [out] ReturnStatus Status code
Returns:
Boolean value: true if the parameter value is a knot value, false otherwise.
Status Codes:
 bool isKnotV ( double param, MStatus * ReturnStatus = `NULL` ) const

Check if the specified parameter value is a knot value.

Parameters:
 [in] param parameter value to test [out] ReturnStatus Status code
Returns:
Boolean value: true if the parameter value is a knot value, false otherwise.
Status Codes:
 bool isParamOnSurface ( double paramU, double paramV, MStatus * ReturnStatus = `NULL` ) const

Check if the specified parameter is on this surface.

Parameters:
 [in] paramU U parameter value [in] paramV V parameter value [out] ReturnStatus Status code
Returns:
Boolean value: true if the parameter value on this surface, false otherwise.
Status Codes:
 MStatus getKnotDomain ( double & startU, double & endU, double & startV, double & endV ) const

Returns the maximum and minimum U and V paramter values for this surface.

Parameters:
 [out] startU Start U parameter value [out] endU End U parameter value [out] startV Start V parameter value [out] endV End V parameter value
Returns:
 int degreeU ( MStatus * ReturnStatus = `NULL` ) const

Returns the degree of the surface in U (1 - 3).

Parameters:
 [out] ReturnStatus Status code
Returns:
The degree in U
Status Codes:
 int degreeV ( MStatus * ReturnStatus = `NULL` ) const

Returns the degree of the surface in V (1 - 3).

Parameters:
 [out] ReturnStatus Status code
Returns:
The degree in V
Status Codes:
 int numSpansInU ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of spans in the u direction.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of spans in U
Status Codes:
 int numSpansInV ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of spans in the v direction.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of spans in V
Status Codes:
 int numNonZeroSpansInU ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of non-zero spans in the U direction.

This value will be equivalent to the value returned by numSpansInU() if all of the internal (non-end) knots are of multiplicity 1. If some of the internal knots have higher multiplicity, this value will be lower than that returned by numSpansInU(). You can use the number of non-zero spans to count the number of visual spans on the surface in the U direction, since the empty (zero) spans do not appear as a separate span/patch in the display.

Further, the NURBS face components have the valid index range bounded by this value in U direction (i.e., the NURBS face component index runs from 0 to numNonEmptySpansInU()-1 inclusivelly.)

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of non-empty (non-zero, visual) spans in U
Status Codes:
 int numNonZeroSpansInV ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of non-zero spans in the V direction.

This value will be equivalent to the value returned by numSpansInV() if all of the internal (non-end) knots are of multiplicity 1. If some of the internal knots have higher multiplicity, this value will be lower than that returned by numSpansInV(). You can use the number of non-zero spans to count the number of visual spans on the surface in the V direction, since the empty (zero) spans do not appear as a separate span/patch in the display.

Further, the NURBS face components have the valid index range bounded by this value in V direction (i.e., the NURBS face component index runs from 0 to numNonEmptySpansInV()-1 inclusivelly.)

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of non-empty (non-zero, visual) spans in V
Status Codes:
 int numCVsInU ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of CVs in the U direction (degree + spans).

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of CVs in U
Status Codes:
 int numCVsInV ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of CVs in the V direction (degree + spans).

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of CVs in V
Status Codes:
 int numKnotsInU ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of knots in U including multiple end knots (spans + 2 * degree - 1).

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of knots in U
Status Codes:
 int numKnotsInV ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of knots in V including multiple end knots (spans + 2 * degree - 1).

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of knots in V
Status Codes:
 MStatus getKnotsInU ( MDoubleArray & array ) const

Get the knots along the U direction for this surface.

Parameters:
 [out] array Storage for the knot values
Returns:
 MStatus getKnotsInV ( MDoubleArray & array ) const

Get the knots along the V direction for this surface.

Parameters:
 [out] array Storage for the knot values
Returns:
 MStatus setKnotsInU ( const MDoubleArray & array, unsigned int startIndex, unsigned int endIndex )

Set the specified U knot values for this surface.

Parameters:
 [in] array The knot values to be set [in] startIndex The start knot index [in] endIndex The end knot index
Returns:
 MStatus setKnotsInV ( const MDoubleArray & array, unsigned int startIndex, unsigned int endIndex )

Set the specified V knot values for this surface.

Parameters:
 [in] array The knot values to be set [in] startIndex The start knot index [in] endIndex The end knot index
Returns:
 double knotInU ( unsigned int index, MStatus * ReturnStatus = `NULL` ) const

Retrieve the given knot value from this surface at the specified U index.

Knots are indexed from 0 to numKnots-1.

Parameters:
 [in] index The U index of the knot value to get [out] ReturnStatus Status code
Returns:
The knot value
Status Codes:
 double knotInV ( unsigned int index, MStatus * ReturnStatus = `NULL` ) const

Retrieve the given knot value from this surface at the specified V index.

Knots are indexed from 0 to numKnots-1.

Parameters:
 [in] index The V index of the knot value to get [out] ReturnStatus Status code
Returns:
The knot value
Status Codes:
 MStatus setKnotInU ( unsigned int index, double param )

Set the value of the given existing knot at the specified U index.

Knots are indexed from 0 to numKnots-1. Note that this routine does not insert a new knot, it simply changes the value of a knot that already exists.

If a knot value is set that breaks the non-decreasing requirement for the knot array, the knot value will be changed and a kInvalidParameter error will be returned.

Parameters:
 [in] index The U index of the existing knot to be set [out] param The new parameter value for the knot
Returns:
 MStatus setKnotInV ( unsigned int index, double param )

Set the value of the given existing knot at the specified V index.

Knots are indexed from 0 to numKnots-1. Note that this routine does not insert a new knot, it simply changes the value of a knot that already exists.

If a knot value is set that breaks the non-decreasing requirement for the knot array, the knot value will be changed and a kInvalidParameter error will be returned.

Parameters:
 [in] index The V index of the existing knot to be set [in] param The new value for the knot
Returns:
 MStatus removeKnotInU ( double atThisParam, bool removeAll = `false` )

Remove the U knot(s) at the specified parameter value from this surface.

If there are multiple knots at this parameter then removeAll is used to specify how to do the removal.

Parameters:
 [in] atThisParam Parameter of knot to be removed [in] removeAll If true then remove all the knots at the given parameter, otherwise remove all except one knot
Returns:
 MStatus removeKnotInV ( double atThisParam, bool removeAll = `false` )

Remove the V knot(s) at the specified parameter value from this surface.

If there are multiple knots at this parameter then removeAll is used to specify how to do the removal.

Parameters:
 [in] atThisParam Parameter of knot to be removed [in] removeAll If true then remove all the knots at the given parameter, otherwise remove all except one knot
Returns:
 MStatus removeOneKnotInU ( double atThisParam )

Remove one U knot at the specified parameter value from this surface.

Parameters:
 [in] atThisParam Parameter of knot to be removed
Returns:
 MStatus removeOneKnotInV ( double atThisParam )

Remove one V knot at the specified parameter value from this surface.

Parameters:
 [in] atThisParam Parameter of knot to be removed
Returns:
 MVector normal ( double paramInU, double paramInV, MSpace::Space space = `MSpace::kObject`, MStatus * ReturnStatus = `NULL` ) const

Retrieve the normal at the given parameter value on the surface.

Parameters:
 [in] paramInU U parameter at which to obtain normal [in] paramInV V parameter at which to obtain normal [in] space Coordinate space for the returned vector [out] ReturnStatus Status code
Returns:
The normal vector
Status Codes:
 MStatus getTangents ( double paramInU, double paramInV, MVector & vectorInU, MVector & vectorInV, MSpace::Space space = `MSpace::kObject` ) const

Retrieve the tangents in the U and V directions at the given parameter value on the surface.

The returned tangent vectors are normalized.

This method does not fail if the given parameter lies within a trimmed away region of a trimmed surface. Use the 'isPointInTrimmedRegion' method to determine if the uv point lies within such a region.

Parameters:
 [in] paramInU U parameter value at which to obtain tangents [in] paramInV V parameter value at which to obtain tangents [out] vectorInU Storage for the U tangent vector [out] vectorInV Storage for the V tangent vector [in] space Coordinate space for the returned vectors
Returns:
 MStatus getDerivativesAtParm ( double paramInU, double paramInV, MPoint & pos, MVector & dU, MVector & dV, MSpace::Space space, MVector * dUU = `NULL`, MVector * dVV = `NULL`, MVector * dUV = `NULL` ) const

Evaluate the surface at the given (u,v) coordinate returning position, first derivatives and optionally second derivative information.

The returned derivative vectors are not normalized. If either dUU, dVV, or dUV is set to NULL, the second derivatives will not be computed and execution time wil be faster.

Parameters:
 [in] paramInU U parameter value to evaluate [in] paramInV V parameter value to evaluate [out] pos Storage for the XYZ position of (u,v) [out] dU Storage for the first order partial derivative with respect to u [out] dV Storage for the first order partial derivative with respect to v [in] space Coordinate space for the returned vectors [out] dUU Pointer to storage for the second order partial derivative with respect to u [out] dVV Pointer to storage for the second order partial derivative with respect to v [out] dUV Pointer to storage for the second order partial derivative with respect to u then v
Returns:
 bool isFoldedOnBispan ( ) const

Evaluate the surface to determine if it contains any folds or creases.

The entire surface including trimmed regions is examined. This function will only check for folds on bispan boundaries and thus will not catch all cases.

Returns:
• true There are folds or creases detected
• false The surface is believed to have continuous curvature
 double area ( double tolerance = `kMFnNurbsEpsilon`, MStatus * ReturnStatus = `NULL` ) const

Calculates the surface area of this nurbs surface.

A value of 0.0 will be returned if the area cannot be determined successfully.

Parameters:
 [in] tolerance tolerance value to be used for computations [out] ReturnStatus Status code
Returns:
The area of this surface
Status Codes:
 double area ( MSpace::Space space, double tolerance = `kMFnNurbsEpsilon`, MStatus * ReturnStatus = `NULL` ) const

Calculates the surface area of this nurbs surface in world or local space.

A value of 0.0 will be returned if the area cannot be determined successfully.

Parameters:
 [in] space Coordinate space for the returned vectors [in] tolerance Tolerance value to be used for computations [out] ReturnStatus Status code
Returns:
The area of this surface
Status Codes:
 MPoint closestPoint ( const MPoint & toThisPoint, double * paramU = `NULL`, double * paramV = `NULL`, bool ignoreTrimBoundaries = `false`, double tolerance = `kMFnNurbsEpsilon`, MSpace::Space space = `MSpace::kObject`, MStatus * ReturnStatus = `NULL` ) const

Return the closest point on this surface to the given point.

Parameters:
 [in] toThisPoint Point to be compared. [out] paramU U parameter value of the closest point. Ignored if null. [out] paramV V parameter value of the closest point. Ignored if null. [in] ignoreTrimBoundaries If this is true and the surface is trimmed, look for the point on the entire, untrimmed surface ignoring any trim curves. [in] tolerance Tolerance value to be used for computations. [in] space Coordinate space in which perform this operation, [out] ReturnStatus Status code.
Returns:
The closest point on this surface to the given point
Status Codes:
 MPoint closestPoint ( const MPoint & toThisPoint, bool paramAsStart, double * paramU, double * paramV, bool ignoreTrimBoundaries = `false`, double tolerance = `kMFnNurbsEpsilon`, MSpace::Space space = `MSpace::kObject`, MStatus * ReturnStatus = `NULL` ) const

Return the closest point on this surface to the given point.

Performance can be greatly increased by supplying a starting parameter value that is reasonably close to the final point and setting 'paramAsStart' to true. However great care must be taken with the use of this parameter and the choice of starting value.

If 'paramAsStart' is true, the algorithm will begin to search for the closest point at the given parameter value, and will check the local surface to see which direction will bring it closer to the given point. It then offsets in this direction and repeats the process, iteratively traversing the surface until it finds the closest point.

This algorithm will fail if it encounters a seam before reaching the closest point, or if it finds a local closest point, such as a bulge on a mesh where an offset in any direction will take it further from the given point, even if that is not the true closest point on the mesh. For this reason it is advisable to avoid using this option unless absolutely sure that the initial point will be a good enough approximation to the final point that these conditions will not occur.

Parameters:
 [in] toThisPoint Point to be compared [in] paramAsStart If true use the value pointed to by paramU and paramV as a starting point for the search [in,out] paramU Returns the U parameter value of the closest point. if 'paramAsStart' is true then the value initially passed in by the caller will be used as the starting U value for the search. Ignored if null. [in,out] paramV Returns the V parameter value of the closest point. if 'paramAsStart' is true then the value initially passed in by the caller will be used as the starting V value for the search. Ignored if null. [in] ignoreTrimBoundaries if this is true and the surface is trimmed, look for the point on the entire, untrimmed surface ignoring any trim curves. [in] tolerance tolerance value to be used for computations [in] space Coordinate space in which perform this operation [out] ReturnStatus Status code
Returns:
The closest point on this surface to the given point
Status Codes:
 bool isPointOnSurface ( const MPoint & point, double tolerance = `kMFnNurbsEpsilon`, MSpace::Space space = `MSpace::kObject`, MStatus * ReturnStatus = `NULL` ) const

Check if the given point is on this surface.

Parameters:
 [in] point Point to test [in] tolerance tolerance value to be used for computations [in] space Coordinate space for this operation [out] ReturnStatus Status code
Returns:
Boolean value: true if the given point is on this surface, false otherwise.
Status Codes:
 MStatus getParamAtPoint ( const MPoint & atThisPoint, double & paramU, double & paramV, MSpace::Space space = `MSpace::kObject` ) const

This method is obsolete.

Deprecated:
This method is obsolete and simply calls the overloaded MFnNurbsSurface::getParamAtPoint method with ignoreTrimBoundaries set to false.
Parameters:
 [in] atThisPoint [out] paramU [out] paramV [in] space
Returns:
Status code
 MStatus getParamAtPoint ( const MPoint & atThisPoint, double & paramU, double & paramV, bool ignoreTrimBoundaries, MSpace::Space space = `MSpace::kObject`, double tolerance = `kMFnNurbsEpsilon` ) const

Get the parameter value corresponding to the given point on the surface (or underlying surface).

Note, when ignoreTrimBoundaries if false, the UV parameters will still be returned if found on the untrimmed surface even though MS::kFailure is returned. This may be useful in cases where you are walking a trim edge and points are determined to be trimmed away because of slight differences between the trim edge and the actual trimmed surface.

Parameters:
 [in] atThisPoint Location of parameter to obtain [out] paramU storage for the U parameter value [out] paramV storage for the V parameter value [in] ignoreTrimBoundaries if this is true and the surface is trimmed, look for the param on the entire, untrimmed surface ignoring any trim curves. [in] space Coordinate space in which to perform this operation [in] tolerance tolerance used in this operation
Returns:
 MStatus getPointAtParam ( double paramU, double paramV, MPoint & point, MSpace::Space space = `MSpace::kObject` ) const

Finds the point corresponding to the given parameter value on the surface.

This method does not fail if the given parameter lies within a trimmed away region of a trimmed surface. Use the 'isPointInTrimmedRegion' method to determine if the uv point lies within such a region.

Parameters:
 [in] paramU U parameter value [in] paramV V parameter value [out] point storage for the found point [in] space Coordinate space in which to perform this operation
Returns:
 double distanceToPoint ( const MPoint & pt, MSpace::Space space = `MSpace::kObject`, MStatus * ReturnStatus = `NULL` ) const

Returns the distance from the given point to the closest point on the surface.

Parameters:
 [in] pt Point to calculate distance from [in] space Coordinate space for which to perform operation [out] ReturnStatus Status code
Returns:
The distance to the given point from this surface
Status Codes:
 MObject tesselate ( MTesselationParams & parms = `MTesselationParams::fsDefaultTesselationParams`, MObject parentOrOwner = `MObject::kNullObj`, MStatus * ReturnStatus = `NULL` )

Performs tesselation on this surface and create a new mesh in the DAG.

The type of tesselation can be controlled by providing the tesselation parameters (see MTesselationParams).

The parentOrOwner argument is used to specify the owner of the new surface.

If the parentOrOwner is kMeshData then the created surface will be of type kMeshGeom and will be returned. The parentOrOwner will become the owner of the new mesh.

If parentOrOwner is NULL then a new transform will be created and returned which will be the parent for the mesh. The new transform will be added to the DAG.

If parentOrOwner is a DAG node then the new mesh will be returned and the parentOrOwner will become its parent.

Parameters:
 [in] parms Tesselation parameters [in] parentOrOwner the DAG parent or kMeshData the new mesh will belong to [out] ReturnStatus Status code
Returns:
• If parentOrOwner is NULL then the transform for this surface is returned
• If parentOrOwner is a DAG object then the new surface shape is returned
• The surface geometry is returned if parentOrOwner is of type kMeshData
Status Codes:
 bool intersect ( const MPoint & rayStartingPoint, const MVector & alongThisDirection, double & u, double & v, MPoint & pntOfIntersection, double tolerance = `kMFnNurbsEpsilon`, MSpace::Space space = `MSpace::kObject`, bool calculateDistance = `false`, double * distance = `NULL`, bool calculateExactHit = `false`, bool * wasExactHit = `NULL`, MStatus * ReturnStatus = `NULL` ) const

This function determines the closest point of intersection of this spline surface with a ray (a vector at a point).

Parameters:
 [in] rayStartingPoint Starting location of ray to test. [in] alongThisDirection Direction of ray to test. [out] u U parameter of intersection (if any). [out] v V parameter of intersection (if any). [out] pntOfIntersection Closest point of intersection (if any). [in] tolerance The epsilon value in the calculation. [in] space Specifies the coordinate system for this operation. [in] calculateDistance Specifies whether to calculate the distance of the startPoint to the point of intersection [out] distance Distance of intersection point from startPoint. Ignored if 'calculateDistance' is false. [in] calculateExactHit Specifies whether to determine if the point of intersection actually hit the object or just came within tolerance of it. [out] wasExactHit Returns true if the point of intersection is an exact hit, false otherwise. Ignored if 'calculateExactHit' if false. [out] ReturnStatus Status code.
Returns:
Boolean value: true if an intersection point has been found, false otherwise.
Status Codes:
 bool intersect ( const MPoint & rayStartingPoint, const MVector & alongThisDirection, MDoubleArray & uArray, MDoubleArray & vArray, MPointArray & points, double tolerance = `kMFnNurbsEpsilon`, MSpace::Space space = `MSpace::kObject`, bool calculateDistance = `false`, MDoubleArray * distances = `NULL`, bool calculateExactHit = `false`, bool * wasExactHit = `NULL`, MStatus * ReturnStatus = `NULL` ) const

This function determines all the points of intersection of this spline surface with a ray (a vector at a point).

Parameters:
 [in] rayStartingPoint Starting location of ray to test. [in] alongThisDirection Direction of ray to test. [out] uArray U parameters of intersections. [out] vArray V parameters of intersections. [out] points Points of intersection. [in] tolerance The epsilon value in the calculation. [in] space Specifies the coordinate system for this operation. [in] calculateDistance Specifies whether to calculate the distances of the startPoint to the all the points of intersection. [out] distances Distances of intersection points from startPoint. Ignored if 'calculateDistance' is false. [in] calculateExactHit Specifies whether to determine if the point of intersection actually hit the object or just came within tolerance of it. [out] wasExactHit Returns true if the point of intersection is an exact hit, false otherwise. Ignored if 'calculateExactHit' if false. [out] ReturnStatus Status code.
Returns:
Boolean value: true if an intersection point has been found, false otherwise.
Status Codes:
 bool hasHistoryOnCreate ( MStatus * ReturnStatus = `NULL` )

This method determines if the shape was created with history.

If the object that this function set is attached to is not a shape then this method will fail.

Parameters:
 [out] ReturnStatus
Returns:
Boolean value: true if the shape has history, false otherwise.
Status Codes:

This method signals that this surface has changed and needs to be recalculated.

This method is useful when a large number of CVs for the surface are being modified. Instead of updating the surface every time a CV is changed it is more efficient to call this method once after updating all of the CVs.

Returns:
 bool isTrimmedSurface ( MStatus * ReturnStatus = `NULL` )

This method determines if this surface is a trimmed surface.

Parameters:
 [out] ReturnStatus
Returns:
Boolean value: true if the surface is trimmed, false otherwise.
Status Codes:
 unsigned int numRegions ( MStatus * ReturnStatus = `NULL` )

Returns the number of trimmed regions for this surface or 0 if the surface is not a trimmed surface.

For each region there may be several boundary curves, an outer curve and possibly several inner boundary curves which define holes. These boundary curves are made up of one or more curves called edges.

Parameters:
 [out] ReturnStatus
Returns:
The number of regions for this surface
Status Codes:
 bool isFlipNorm ( unsigned int region, MStatus * ReturnStatus = `NULL` )

Determines whether the normal for the specified region is flipped.

This method is only valid for trimmed surfaces.

Parameters:
 [in] region Trimmed region to check. Must be in the range 0 to numRegions() - 1. [out] ReturnStatus Status code
Returns:
• true normal = -dS/du X dS/dv
• false normal = dS/du X dS/dv
Status Codes:
 unsigned int numBoundaries ( unsigned int region, MStatus * ReturnStatus = `NULL` )

Returns the number of boudaries for the specified region.

The surface must be a trimmed surface.

For each region there may be several boundary curves, an outer curve and possibly several inner boundary curves which define holes. These boundary curves are made up of one or more curves called edges.

Parameters:
 [in] region The trimmed region to examine [out] ReturnStatus status code
Returns:
The number of boundaries for the specified region
Status Codes:
 MFnNurbsSurface::BoundaryType boundaryType ( unsigned int region, unsigned int boundary, MStatus * ReturnStatus = `NULL` )

Returns the type of the specified boundary.

The surface must be a trimmed surface.

Possible boundary types are Inner, kOuter, kSegment, kClosedSegment, and kInvalidBoundary

Parameters:
 [in] region the region to examine [in] boundary the boundary to examine [out] ReturnStatus status code
Returns:
The boundary type:
• kInner an inner boundary, clockwise
• kOuter an outer boundary, counter clockwise
• kSegment a boundary segment (a curve on face)
• kClosedSegment a closed boundary segment (a closed curve on face)
• kInvalidBoundary an invalid boundary type
Status Codes:
 unsigned int numEdges ( unsigned int region, unsigned int boundary, MStatus * ReturnStatus = `NULL` )

Return the number of edges for the specified trim boundary.

For each region there may be several boundary curves, an outer curve and possibly several inner boundary curves which define holes. These boundary curves are made up of one or more curves called edges.

Parameters:
 [in] region Region to examine [in] boundary Boundary to examine [out] ReturnStatus Status code
Returns:
The number of edges for the specified boundary
Status Codes:
 MObjectArray edge ( unsigned int region, unsigned int boundary, unsigned int edge, bool paramEdge = `false`, MStatus * ReturnStatus = `NULL` )

Return the specified edge of a trim boundary.

For each region of a trimmed surface there may be several boundary curves; an outer curve and possibly several inner boundary curves (which define holes). These boundary curves are made up of one or more curves called edges. The edge is returned as an MObjectArray as the edge may consist of more than one curve. The returned edge, or trim curve, can be a 2D parameter edge or a 3D edge curve. To identify an edge you must specify the trimmed region, the boundary of that region, and the edge of that boundary.

Note that for closed surfaces some of the 3d edges may be 0 length in which case an empty MObjectArray is returned. An example of this is the poles of a sphere.

Parameters:
 [in] region the trimmed region containing the edge [in] boundary the boundary to examine [in] edge the boundary edge to examine [in] paramEdge if true then 2D param edges are returned, otherwise a 3D edge is returned. [out] ReturnStatus status code
Returns:
A curve for the specified edge
Status Codes:
 bool isPointInTrimmedRegion ( double u, double v, MStatus * ReturnStatus = `NULL` )

Returns true if the given point is in a trimmed away region of a trimmed surface.

A trimmed away region is the part of the surface that is cut away as a result of a trim operation.

Parameters:
 [in] u u parameter of point on surface to test [in] v v parameter of point on surface to test [out] ReturnStatus status code
Returns:
Boolean value: true if the point on surface is within a trimmed away region, false otherwise.
Status Codes:
 MStatus getTrimBoundaries ( MTrimBoundaryArray & result, unsigned int region, bool paramEdge = `true` )

Returns all trim boundaries of a region on this surface.

Parameters:
 [out] result All trim boundaries of the given region in this surface. [in] region the trimmed region that containing the boundaries [in] paramEdge If true, then 2D curves are returned, otherwise 3D curves.
Returns:
 MStatus trimWithBoundaries ( const MTrimBoundaryArray & mBoundaries, bool flipNormal = `false`, double e_tol = `1e-3`, double pe_tol = `1e-5`, bool createNewRegion = `false` )

This function trims this surface with given trim boundaries.

NOTE: The curves specified in the MTrimBoundaryArray are in UV space. As a result, they must be 2D curves. The MFnNurbsCurve functionset provides a method for creating 2D curves.

Parameters:
 [in] mBoundaries The boundaries used for the trim. A boundary may consist of several curves. They must present a closed boundary, must be in UV (parameter) space, and must be on the surface. Boundaries[0] is the outer boundary which goes counterclockwise around the surface normal. All other boundaries must be inner boundaries inside the outer boundary defined region. A clockwise inner boundary defines a hole. Boundaries[0] can be empty. In this case, the native boundary is used as outer boundary. The boundaries should not intersect to each other or to itself. [in] flipNormal Whether to flip the trimmed surface normal [in] e_tol The 3d edge tolerance with which to trim [in] pe_tol The parameter edge tolerance with which to trim [in] createNewRegion Whether to create a new region on the trimmed surface. A region is a disjoint area of a trimmed surface.
Returns:
 MStatus projectCurve ( MDagPath & curve, MVector * direction = `NULL`, bool constructionHistory = `false` )

Project the given curve onto this surface creating a curve on surface.

Projection will be done using the surface normals unless a direction vector to project along is given.

Parameters:
 [in] curve curve to be projected [in] direction direction of projection. If this is null then the surface normals is used [in] constructionHistory keep construction history
Returns:
 MStatus trim ( MDoubleArray & locatorU, MDoubleArray & locatorV, bool constructionHistory = `false` )

Trim this surface to its curves on surface.

Regions which are kept are specified by passing in two arrays of u,v parameters.

This method will create a new trimmed surface in the DAG. The surface attached to this function set will remain unchanged.

Parameters:
 [in] locatorU array of U parameters indicating regions to keep [in] locatorV array of V parameters indicating regions to keep [in] constructionHistory keep construction history
Returns:
 unsigned int numPatches ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of non-zero patches in this surface.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of non-zero patches in this surface.
Status Codes:
 unsigned int numPatchesInU ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of non-zero patches along u, in this surface.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of non-zero patches along u, in this surface.
Status Codes:
 unsigned int numPatchesInV ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of non-zero patches along v, in this surface.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of non-zero patches along v, in this surface.
Status Codes:
 int numUVs ( MStatus * ReturnStatus = `NULL` ) const

Returns the number of texture (uv) coordinates for this surface.

The uv's are stored in a list which is referenced by patches requiring textures on a per-patch per-patchCorner basis. This method returns the number of elements in this list.

Parameters:
 [out] ReturnStatus Status code
Returns:
The number of texture coordinates
Status Codes:
 MStatus setUVs ( const MFloatArray & uArray, const MFloatArray & vArray )

Sets all of the texture coordinates (uvs) for this surface.

The uv arrays must be of equal size and must be at least of length numUVs(). If the arrays are larger than numUVs() then the uv list for this surface will be grown to accommodate the new uv values.

After using this method to set the UV values, you can call assignUVs to assign the corresponding UVids to the geometry.

Also, note that API methods that modify uv data, work correctly either when called through a plug-in node that is in the history of the shape, or when used on a surface shape that does not have history. Modifying uvs directly on a shape with history will result in the modifications getting over-written by the next evaluation of the history attached to the shape.

Parameters:
 [in] uArray The array of u values to be set [in] vArray The array of v values to be set
Returns:
 MStatus getUVs ( MFloatArray & uArray, MFloatArray & vArray ) const

This method copies the texture coordinate list for this surface into the given uv arrays.

Parameters:
 [out] uArray Storage for the u texture coordinate list [out] vArray Storage for the v texture coordinate list
Returns:
 MStatus setUV ( int uvId, float u, float v )

Sets the specified texture coordinate.

The uvId is the element in the uv list that will be set. If the uvId is greater than or equal to numUVs() then the uv list will be grown to accommodate the specified uv.

Also, note that API methods that modify uv data, work correctly either when called through a plug-in node that is in the history of the shape, or when used on a surface shape that does not have history. Modifying uvs directly on a shape with history will result in the modifications getting over-written by the next evaluation of the history attached to the shape.

Parameters:
 [in] uvId the element in the uv list to be set [in] u the new u value that is to be set [in] v the new v value that is to be set
Returns:
 MStatus getUV ( int uvId, float & u, float & v ) const

Get the value of the specified texture coordinate from this surface's uv list.

The uvId is the element in the uv list that will be retrieved.

Parameters:
 [in] uvId the element in the uv list to examine [out] u storage for the u value [out] v storage for the v value
Returns:
 MStatus getPatchUV ( int patchId, int cornerIndex, float & u, float & v ) const

Get the value of the specified texture coordinate for a patch corner in a patch.

Since texture coordinates (uv's) are stored per-patch per-corner you must specify both the patch and the corner that the u and v values are mapped to.

Parameters:
 [in] patchId The patch to examine [in] cornerIndex The patch-relative corner to examine [out] u storage for the u value [out] v storage for the v value
Returns:
 MStatus getPatchUVs ( int patchId, MFloatArray & uArray, MFloatArray & vArray ) const

Get the values of the texture coordinate on a specified patch.

Since texture coordinates (uvs) are stored per-patch per-corner, the u and v values mapped to all corners of the specified patch are returned.

Parameters:
 [in] patchId The patch to examine [out] uArray storage for u values [out] vArray storage for v values
Returns:
 MStatus getPatchUVid ( int patchId, int cornerIndex, int & uvId ) const

Get the id of the specified texture coordinate for a corner in a patch.

Parameters:
 [in] patchId The patch to examine [in] cornerIndex The patch-relative corner to examine (local index) [out] uvId storage for the uv index
Returns:
 MStatus assignUV ( int patchId, int cornerIndex, int uvId )

Maps a texture coordinate to a the specified corner of a patch.

Since texture coordinates (uvs) are stored per-patch per-patchCorner you must specify both the patch and the patchCorner that the uv entry is mapped to.

The cornerIndex is the corner within the patch that the uv will be mapped to. This index must be in the range 0 to patchCornerCount(patchId).

Also, note that API methods that modify uv data, work correctly either when called through a plug-in node that is in the history of the shape, or when used on a surface shape that does not have history. Modifying uvs directly on a shape with history will result in the modifications getting over-written by the next evaluation of the history attached to the shape.

Parameters:
 [in] patchId The patch to map to [in] cornerIndex The corner of the patch to map to [in] uvId The uv entry from the uv list that will be mapped
Returns:
 MStatus assignUVs ( const MIntArray & uvCounts, const MIntArray & uvIds )

This method maps all texture coordinates for the surface.

The setUV/setUVs method is used to create the texture coordinate table for the surface. After the table is created, this method is used to map those values to each patch on a per-corner basis. The setUV/setUVs method should be called before the assignUVs method.

The uvCounts array should contain the number of uvs per patch. Since uvs are mapped per-patch per-corner, the entries in this array should match the corner counts for each patch in the surface.

If an entry in this array is '0' then the corresponding patch will not be mapped. The sum of all the entries in the uvCounts array must be equal to the size of the uvIds array or this method will fail.

The uvIds array should contain the UV indices that will be mapped to each patch-corner in the surface. The entries in this array specify which uvs in the surface's uv table are mapped to each patch-corner. Each entry in the uvIds array must be less than numUVs(). The size of the uvIds array is equivalent to adding up all of the entries in the uvCounts array, so for a cube with all patches mapped there would be 24 entries.

Also, note that API methods that modify uv data, work correctly either when called through a plug-in node that is in the history of the shape, or when used on a surface shape that does not have history. Modifying uvs directly on a shape with history will result in the modifications getting over-written by the next evaluation of the history attached to the shape.

Parameters:
 [in] uvCounts The uv counts for each patch in the surface [in] uvIds The uv indices to be mapped to each patch-corner
Returns:
 MStatus clearUVs ( )

This method clears out all texture coordinates for the nurbsSurface, and leaves behind an empty UVset.

This method should be used if it is needed to shrink the actual size of the UV table. In this case, the user should call clearUVs, setUVs and then assignUVs to rebuild the mapping info.

When called on a dataNurbsSurface, the UVs are removed. When called on a shape with no history, the UVs are removed and the attributes are set on the shape. When called on a shape with history, the polyDelMap command is invoked and a polyMapDel node is created.

Returns:
 MStatus getAssignedUVs ( MIntArray & uvCounts, MIntArray & uvIds ) const

Get assigned UVs.

This method finds all texture coordinates for the surface that have been mapped, and returns them in the same format as assignUVs. The setUV/setUVs method is used to create the texture coordinate table for the surface and this method is used to map those values to each patch on a per-corner basis.

The uvCounts array should contain the number of uv's per patch. Since uvs are mapped per-patch per-corner, the entries returned in this array will match the corner counts for each patch in the surface. For example, suppose that we have a cube with 2 of the faces mapped: the array for this cube would be { 4, 4, 0, 0, 0, 0 } since there are 6 patches each with 4 vertices. A face either has all its vertives mapped, or none

The uvIds array will contain the UV indices that will be mapped to each patch-corner in the surface. Use the getUV method to get the actual uv values for these id's.

Parameters:
 [out] uvCounts The uv counts for each patch in the surface [out] uvIds The uv indices to be mapped to each patch-corner
Returns:
 MObject tesselate ( MTesselationParams & parms, MStatus * ReturnStatus )

This method is obsolete.

Deprecated:

Performs tesselation on this surface and returns the tesselated polygonal object. The type of tesselation can be controlled by providing the tesselation parameters (see MTesselationParams).

Parameters:
 [in] parms Tesselation parameters [out] ReturnStatus Status code
Returns:
A polygonal representation of this surface
Status Codes:
 MObject getDataObject ( ) const

Returns an MObject if the class has been constructed with an MFn::kNurbsSurfaceData entity, otherwise MObject::kNullObj is returned.

Returns:
An MObject

MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface
MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface MFnNurbsSurface