Describes a B-Spline surface in 3D space
Content of the object in XML representation
Returns the global continuity of the surface.
Returns the index in the knot array associated with the u parametric direction,
which corresponds to the first parameter of this B-Spline surface in the specified
parametric direction.
The isoparametric curves corresponding to these values are the boundary curves of
this surface.
Note: The index does not correspond to the first knot of the surface in the specified
parametric direction unless the multiplicity of the first knot is equal to Degree + 1,
where Degree is the degree of this surface in the corresponding parametric direction.
Returns the index in the knot array associated with the v parametric direction,
which corresponds to the first parameter of this B-Spline surface in the specified
parametric direction.
The isoparametric curves corresponding to these values are the boundary curves of
this surface.
Note: The index does not correspond to the first knot of the surface in the specified
parametric direction unless the multiplicity of the first knot is equal to Degree + 1,
where Degree is the degree of this surface in the corresponding parametric direction.
Returns the index in the knot array associated with the u parametric direction,
which corresponds to the last parameter of this B-Spline surface in the specified
parametric direction.
The isoparametric curves corresponding to these values are the boundary curves of
this surface.
Note: The index does not correspond to the first knot of the surface in the specified
parametric direction unless the multiplicity of the last knot is equal to Degree + 1,
where Degree is the degree of this surface in the corresponding parametric direction.
Returns the index in the knot array associated with the v parametric direction,
which corresponds to the last parameter of this B-Spline surface in the specified
parametric direction.
The isoparametric curves corresponding to these values are the boundary curves of
this surface.
Note: The index does not correspond to the first knot of the surface in the specified
parametric direction unless the multiplicity of the last knot is equal to Degree + 1,
where Degree is the degree of this surface in the corresponding parametric direction.
Returns the value of the maximum polynomial degree of any
B-Spline surface surface in either parametric directions.
This value is 25.
Memory size of the object in byte
Module in which this class is defined
Returns the number of knots of this B-Spline surface in the u parametric direction.
Returns the number of poles of this B-Spline surface in the u parametric direction.
Returns the number of knots of this B-Spline surface in the v parametric direction.
Returns the number of poles of this B-Spline surface in the v parametric direction.
Returns a rotation object to describe the orientation for surface that supports it
Gives the tag of the geometry as string.
Is the type of the FreeCAD object with module domain
Returns the degree of this B-Spline surface in the u parametric direction.
Returns the knots sequence of this B-Spline surface in
the u direction.
Returns the period of this patch in the u parametric direction.
Returns the degree of this B-Spline surface in the v parametric direction.
Returns the knots sequence of this B-Spline surface in
the v direction.
Returns the period of this patch in the v parametric direction.
Replaces this B-Spline surface by approximating a set of points.
This method uses keywords :
- Points = 2Darray of points (or floats, in combination with X0, dX, Y0, dY)
- DegMin (int), DegMax (int)
- Continuity = 0,1 or 2 (for C0, C1, C2)
- Tolerance (float)
- X0, dX, Y0, dY (floats) with Points = 2Darray of floats
- ParamType = 'Uniform','Centripetal' or 'ChordLength'
- LengthWeight, CurvatureWeight, TorsionWeight (floats)
(with this smoothing algorithm, continuity C1 requires DegMax >= 3 and C2, DegMax >=5)
Possible combinations :
- approximate(Points, DegMin, DegMax, Continuity, Tolerance)
- approximate(Points, DegMin, DegMax, Continuity, Tolerance, X0, dX, Y0, dY)
With explicit keywords :
- approximate(Points, DegMin, DegMax, Continuity, Tolerance, ParamType)
- approximate(Points, DegMax, Continuity, Tolerance, LengthWeight, CurvatureWeight, TorsionWeight)
Returns the parametric bounds (U1, U2, V1, V2) of this B-Spline surface.
Builds a B-Spline from a list of control curves
Builds a B-Spline by a lists of Poles, Mults and Knots
arguments: poles (sequence of sequence of Base.Vector), umults, vmults, [uknots, vknots, uperiodic, vperiodic, udegree, vdegree, weights (sequence of sequence of float)]
Create a clone of this geometry with the same Tag
Create a copy of this geometry
curvature(u,v,type) -> float The value of type must be one of this: Max, Min, Mean or Gauss Computes the curvature of parameter (u,v) on this geometry
curvatureDirections(u,v) -> (Vector,Vector) Computes the directions of maximum and minimum curvature of parameter (u,v) on this geometry. The first vector corresponds to the maximum curvature, the second vector corresponds to the minimum curvature.
Deletes all extensions of the indicated name.
Deletes all extensions of the indicated type.
Dumps the content of the object, both the XML representation as well as the additional datafiles
required, into a byte representation. It will be returned as byte array.
dumpContent() -- returns a byte array with full content
dumpContent(Compression=1-9) -- Sets the data compression from 0 (no) to 9 (max)
Exchanges the u and v parametric directions on this B-Spline surface.
As a consequence:
-- the poles and weights tables are transposed,
-- the knots and multiplicities tables are exchanged,
-- degrees of continuity and rational, periodic and uniform
characteristics are exchanged and
-- the orientation of the surface is reversed.
Returns all descendants
Returns the point of given parameter
Returns the n-th derivative
Gets the first geometry extension of the name indicated by the string.
Gets the first geometry extension of the type indicated by the string.
Returns a list with information about the geometry extensions.
Returns the pole of index (UIndex,VIndex) of this B-Spline surface.
Returns the table of poles of this B-Spline surface.
Returns the table of poles and weights in homogeneous coordinates.
Computes two tolerance values for this B-Spline surface, based on the
given tolerance in 3D space Tolerance3D. The tolerances computed are:
-- UTolerance in the u parametric direction and
-- VTolerance in the v parametric direction.
If f(u,v) is the equation of this B-Spline surface, UTolerance and
VTolerance guarantee that:
|u1 - u0| < UTolerance
|v1 - v0| < VTolerance
====> ||f(u1, v1) - f(u2, v2)|| < Tolerance3D
Returns, for this B-Spline surface, in the u parametric direction
the knot of index UIndex of the knots table.
Returns, for this B-Spline surface, the knots table
in the u parametric direction
Returns, for this B-Spline surface, the table of
multiplicities in the u parametric direction
Returns, for this B-Spline surface, the multiplicity of
the knot of index UIndex in the u parametric direction.
Returns, for this B-Spline surface, in the v parametric direction
the knot of index VIndex of the knots table.
Returns, for this B-Spline surface, the knots table
in the v parametric direction
Returns, for this B-Spline surface, the table of
multiplicities in the v parametric direction
Returns, for this B-Spline surface, the multiplicity of
the knot of index VIndex in the v parametric direction.
Return the weight of the pole of index (UIndex,VIndex)
in the poles table for this B-Spline surface.
Returns the table of weights of the poles for this B-Spline surface.
Returns a boolean indicating whether a geometry extension with the name indicated as a string exists.
Returns a boolean indicating whether a geometry extension of the type indicated as a string exists.
increase(Int=UDegree, int=VDegree)
Increases the degrees of this B-Spline surface to UDegree and VDegree
in the u and v parametric directions respectively.
As a result, the tables of poles, weights and multiplicities are modified.
The tables of knots is not changed.
Note: Nothing is done if the given degree is less than or equal to the
current degree in the corresponding parametric direction.
Increases the multiplicity in the u direction.
Increases the multiplicity in the v direction.
Increment the multiplicity in the u direction
Increment the multiplicity in the v direction
insertUKnote(float U, int Index, float Tolerance) - Insert or override a knot
insertUKnote(List of float U, List of float Mult, float Tolerance) - Inserts knots.
insertUKnote(float V, int Index, float Tolerance) - Insert or override a knot.
insertUKnote(List of float V, List of float Mult, float Tolerance) - Inserts knots.
interpolate(points)
interpolate(zpoints, X0, dX, Y0, dY)
Replaces this B-Spline surface by interpolating a set of points.
The resulting surface is of degree 3 and continuity C2.
Arguments:
a 2 dimensional array of vectors, that the surface passes through
or
a 2 dimensional array of floats with the z values,
the x starting point X0 (float),
the x increment dX (float),
the y starting point Y0 and increment dY
Returns all intersection points/curves between the surface and the curve/surface.
Returns all intersection curves of this surface and the given surface. The required arguments are:
- Second surface
- precision code (optional, default=0)
Returns true if given type is a father
isPlanar([float]) -> Bool Checks if the surface is planar within a certain tolerance.
Checks if this surface is closed in the u parametric direction.
Returns true if, in the table of poles the first row and the last
row are identical.
Returns true if this surface is periodic in the u parametric direction.
Returns false if the equation of this B-Spline surface is polynomial
(e.g. non-rational) in the u or v parametric direction.
In other words, returns false if for each row of poles, the associated
weights are identical
isUmbillic(u,v) -> bool Check if the geometry on parameter is an umbillic point, i.e. maximum and minimum curvature are equal.
Checks if this surface is closed in the v parametric direction.
Returns true if, in the table of poles the first column and the
last column are identical.
Returns true if this surface is periodic in the v parametric direction.
Returns false if the equation of this B-Spline surface is polynomial
(e.g. non-rational) in the u or v parametric direction.
In other words, returns false if for each column of poles, the associated
weights are identical
Performs the symmetrical transformation of this geometric object
Moves the point of parameters (U, V) of this B-Spline surface to P.
UIndex1, UIndex2, VIndex1 and VIndex2 are the indexes in the poles
table of this B-Spline surface, of the first and last poles which
can be moved in each parametric direction.
The returned indexes UFirstIndex, ULastIndex, VFirstIndex and
VLastIndex are the indexes of the first and last poles effectively
modified in each parametric direction.
In the event of incompatibility between UIndex1, UIndex2, VIndex1,
VIndex2 and the values U and V:
-- no change is made to this B-Spline surface, and
-- UFirstIndex, ULastIndex, VFirstIndex and VLastIndex are set to
null.
normal(u,v) -> Vector Computes the normal of parameter (u,v) on this geometry
Returns the parameter on the curve of the nearest orthogonal projection of the point.
Computes the projection of a point on the surface
projectPoint(Point=Vector,[Method="NearestPoint"]) projectPoint(Vector,"NearestPoint") -> Vector projectPoint(Vector,"LowerDistance") -> float projectPoint(Vector,"LowerDistanceParameters") -> tuple of floats (u,v) projectPoint(Vector,"Distance") -> list of floats projectPoint(Vector,"Parameters") -> list of tuples of floats projectPoint(Vector,"Point") -> list of points
Reduces to M the multiplicity of the knot of index Index in the given
parametric direction. If M is 0, the knot is removed.
With a modification of this type, the table of poles is also modified.
Two different algorithms are used systematically to compute the new
poles of the surface. For each pole, the distance between the pole
calculated using the first algorithm and the same pole calculated using
the second algorithm, is checked. If this distance is less than Tolerance
it ensures that the surface is not modified by more than Tolerance.
Under these conditions, the function returns true; otherwise, it returns
false.
A low tolerance prevents modification of the surface. A high tolerance
'smoothes' the surface.
Reduces to M the multiplicity of the knot of index Index in the given
parametric direction. If M is 0, the knot is removed.
With a modification of this type, the table of poles is also modified.
Two different algorithms are used systematically to compute the new
poles of the surface. For each pole, the distance between the pole
calculated using the first algorithm and the same pole calculated using
the second algorithm, is checked. If this distance is less than Tolerance
it ensures that the surface is not modified by more than Tolerance.
Under these conditions, the function returns true; otherwise, it returns
false.
A low tolerance prevents modification of the surface. A high tolerance
'smoothes' the surface.
Returns a reparametrized copy of this surface
Restore the content of the object from a byte representation as stored by "dumpContent". It could be restored from any python object implementing the buffer protocol. restoreContent(buffer) -- restores from the given byte array
Rotates this geometric object at angle Ang (in radians) about axis
Applies a scaling transformation on this geometric object with a center and scaling factor
Modifies this B-Spline surface by segmenting it between U1 and U2 in the
u parametric direction and between V1 and V2 in the v parametric direction.
Any of these values can be outside the bounds of this surface, but U2 must
be greater than U1 and V2 must be greater than V1.
All the data structure tables of this B-Spline surface are modified but the
knots located between U1 and U2 in the u parametric direction, and between
V1 and V2 in the v parametric direction are retained.
The degree of the surface in each parametric direction is not modified.
Sets a geometry extension of the indicated type.
Modifies this B-Spline surface by assigning P to the pole of
index (UIndex, VIndex) in the poles table.
The second syntax allows you also to change the weight of the
modified pole. The weight is set to Weight. This syntax must
only be used for rational surfaces.
Modifies this B-Spline curve by assigning P to the pole of
index Index in the poles table.
Modifies this B-Spline surface by assigning values to all or part
of the column of poles of index VIndex, of this B-Spline surface.
You can also change the weights of the modified poles. The weights
are set to the corresponding values of CPoleWeights.
These syntaxes must only be used for rational surfaces.
Modifies this B-Spline surface by assigning values to all or part
of the row of poles of index VIndex, of this B-Spline surface.
You can also change the weights of the modified poles. The weights
are set to the corresponding values of CPoleWeights.
These syntaxes must only be used for rational surfaces.
Modifies this B-Spline surface by assigning the value K to the knot of index
UIndex of the knots table corresponding to the u parametric direction.
This modification remains relatively local, since K must lie between the values
of the knots which frame the modified knot.
You can also increase the multiplicity of the modified knot to M. Note however
that it is not possible to decrease the multiplicity of a knot with this function.
Changes all knots of this B-Spline surface in the u parametric
direction. The multiplicity of the knots is not modified.
Changes this B-Spline surface into a non-periodic one in the u parametric direction.
If this B-Spline surface is already non-periodic in the given parametric direction,
it is not modified.
If this B-Spline surface is periodic in the given parametric direction, the boundaries
of the surface are not given by the first and last rows (or columns) of poles (because
the multiplicity of the first knot and of the last knot in the given parametric direction
are not modified, nor are they equal to Degree+1, where Degree is the degree of this
B-Spline surface in the given parametric direction). Only the function Segment ensures
this property.
Note: the poles and knots tables are modified.
Assigns the knot of index Index in the knots table
in the u parametric direction to be the origin of
this periodic B-Spline surface. As a consequence,
the knots and poles tables are modified.
Modifies this surface to be periodic in the u parametric direction.
To become periodic in a given parametric direction a surface must
be closed in that parametric direction, and the knot sequence relative
to that direction must be periodic.
To generate this periodic sequence of knots, the functions FirstUKnotIndex
and LastUKnotIndex are used to compute I1 and I2. These are the indexes,
in the knot array associated with the given parametric direction, of the
knots that correspond to the first and last parameters of this B-Spline
surface in the given parametric direction. Hence the period is:
Knots(I1) - Knots(I2)
As a result, the knots and poles tables are modified.
Modifies this B-Spline surface by assigning the value K to the knot of index
VIndex of the knots table corresponding to the v parametric direction.
This modification remains relatively local, since K must lie between the values
of the knots which frame the modified knot.
You can also increase the multiplicity of the modified knot to M. Note however
that it is not possible to decrease the multiplicity of a knot with this function.
Changes all knots of this B-Spline surface in the v parametric
direction. The multiplicity of the knots is not modified.
Changes this B-Spline surface into a non-periodic one in the v parametric direction.
If this B-Spline surface is already non-periodic in the given parametric direction,
it is not modified.
If this B-Spline surface is periodic in the given parametric direction, the boundaries
of the surface are not given by the first and last rows (or columns) of poles (because
the multiplicity of the first knot and of the last knot in the given parametric direction
are not modified, nor are they equal to Degree+1, where Degree is the degree of this
B-Spline surface in the given parametric direction). Only the function Segment ensures
this property.
Note: the poles and knots tables are modified.
Assigns the knot of index Index in the knots table
in the v parametric direction to be the origin of
this periodic B-Spline surface. As a consequence,
the knots and poles tables are modified.
Modifies this surface to be periodic in the v parametric direction.
To become periodic in a given parametric direction a surface must
be closed in that parametric direction, and the knot sequence relative
to that direction must be periodic.
To generate this periodic sequence of knots, the functions FirstUKnotIndex
and LastUKnotIndex are used to compute I1 and I2. These are the indexes,
in the knot array associated with the given parametric direction, of the
knots that correspond to the first and last parameters of this B-Spline
surface in the given parametric direction. Hence the period is:
Knots(I1) - Knots(I2)
As a result, the knots and poles tables are modified.
Modifies this B-Spline surface by assigning the value Weight to the weight
of the pole of index (UIndex, VIndex) in the poles tables of this B-Spline
surface.
This function must only be used for rational surfaces.
Modifies this B-Spline surface by assigning values to all or part of the
weights of the column of poles of index VIndex of this B-Spline surface.
The modified part of the column of weights is defined by the bounds
of the array CPoleWeights.
This function must only be used for rational surfaces.
Modifies this B-Spline surface by assigning values to all or part of the
weights of the row of poles of index UIndex of this B-Spline surface.
The modified part of the row of weights is defined by the bounds of the
array CPoleWeights.
This function must only be used for rational surfaces.
tangent(u,v) -> (Vector,Vector) Computes the tangent of parameter (u,v) on this geometry
Returns a B-Spline representation of this surface.
The optional arguments are:
* tolerance (default=1e-7)
* continuity in u (as string e.g. C0, G0, G1, C1, G2, C3, CN) (default='C1')
* continuity in v (as string e.g. C0, G0, G1, C1, G2, C3, CN) (default='C1')
* maximum degree in u (default=25)
* maximum degree in v (default=25)
* maximum number of segments (default=1000)
* precision code (default=0)
Will raise an exception if surface is infinite in U or V (like planes, cones or cylinders)
Return the shape for the geometry.
Make a shell of the surface.
Applies a transformation to this geometric object
Translates this geometric object
Builds the U isoparametric curve
Builds the V isoparametric curve
value(u,v) -> Point Computes the point of parameter (u,v) on this surface
documentation index > API > BSplineSurface API