TopoShapeEdge is the OpenCasCade topological edge wrapper paramval = getParameterByLength(pos, [tolerance = 1e-7]) Get the value of the primary parameter at the given distance along the cartesian length of the edge. Args: pos (float or int): The distance along the length of the edge at which to determine the primary parameter value. See help for the FirstParameter or LastParameter properties for more information on the primary parameter. If the given value is positive, the distance from edge start is used. If the given value is negative, the distance from edge end is used. tol (float): Computing tolerance. Optional, defaults to 1e-7. Returns: paramval (float): the value of the primary parameter defining the edge at the given position along its cartesian length. Vector = tangentAt(paramval) Get the tangent direction at the given primary parameter value along the Edge if it is defined Args: paramval (float or int): The parameter value along the Edge at which to determine the tangent direction e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.tangentAt(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is the Vector (-0.7071067811865475, 0.7071067811865476, 0.0) Values with magnitude greater than the Edge length return values of the tangent on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a tangent on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.tangentAt(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865477, 0.7071067811865474, 0.0) Which gives the same result as >>> x.tangentAt(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865475, 0.7071067811865476, 0.0) Since it is a circle Returns: Vector: representing the tangent to the Edge at the given location along its length (or extrapolated length) Vector = valueAt(paramval) Get the value of the cartesian parameter value at the given parameter value along the Edge Args: paramval (float or int): The parameter value along the Edge at which to determine the value in terms of the main parameter defining the edge, what the parameter value is depends on the type of edge. See e.g: For a circle value x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.valueAt(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is theVector (0.7071067811865476, 0.7071067811865475, 0.0) Values with magnitude greater than the Edge length return values on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a parameter value on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.valueAt(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865474, -0.7071067811865477, 0.0) Which gives the same result as >>> x.valueAt(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865476, -0.7071067811865475, 0.0) Since it is a circle Returns: Vector: representing the cartesian location on the Edge at the given distance along its length (or extrapolated length) parameters([face]) --> list Get the list of parameters of the tessellation of an edge. If the edge is part of a face then this face is required as argument. An exception is raised if the edge has no polygon. Float = parameterAt(Vertex) - Get the parameter at the given vertex if lying on the edge Vector = normalAt(paramval) Get the normal direction at the given parameter value along the Edge if it is defined Args: paramval (float or int): The parameter value along the Edge at which to determine the normal direction e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.normalAt(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is the Vector (-0.7071067811865476, -0.7071067811865475, 0.0) Values with magnitude greater than the Edge length return values of the normal on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a normal on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.normalAt(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865474, 0.7071067811865477, 0.0) Which gives the same result as >>> x.normalAt(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865476, 0.7071067811865475, 0.0) Since it is a circle Returns: Vector: representing the normal to the Edge at the given location along its length (or extrapolated length) Vector = derivative1At(paramval) Get the first derivative at the given parameter value along the Edge if it is defined Args: paramval (float or int): The parameter value along the Edge at which to determine the first derivative e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.derivative1At(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is the Vector (-0.7071067811865475, 0.7071067811865476, 0.0) Values with magnitude greater than the Edge length return values of the first derivative on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a first derivative on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.derivative1At(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865477, 0.7071067811865474, 0.0) Which gives the same result as >>> x.derivative1At(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (0.7071067811865475, 0.7071067811865476, 0.0) Since it is a circle Returns: Vector: representing the first derivative to the Edge at the given location along its length (or extrapolated length) Vector = derivative2At(paramval) Get the second derivative at the given parameter value along the Edge if it is defined Args: paramval (float or int): The parameter value along the Edge at which to determine the second derivative e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.derivative2At(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is the Vector (-0.7071067811865476, -0.7071067811865475, 0.0) Values with magnitude greater than the Edge length return values of the second derivative on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a second derivative on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.derivative2At(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865474, 0.7071067811865477, 0.0) Which gives the same result as >>> x.derivative2At(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865476, 0.7071067811865475, 0.0) Since it is a circle Returns: Vector: representing the second derivative to the Edge at the given location along its length (or extrapolated length) Vector = derivative3At(paramval) Get the third derivative at the given parameter value along the Edge if it is defined Args: paramval (float or int): The parameter value along the Edge at which to determine the third derivative e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.derivative3At(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) y is the Vector (0.7071067811865475, -0.7071067811865476, -0.0) Values with magnitude greater than the Edge length return values of the third derivative on the curve extrapolated beyond its length. This may not be valid for all Edges. Negative values similarly return a third derivative on the curve extrapolated backwards (before the start point of the Edge). For example, using the same shape as above: >>> x.derivative3At(x.FirstParameter + 3.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865477, -0.7071067811865474, 0.0) Which gives the same result as >>> x.derivative3At(x.FirstParameter -0.5*(x.LastParameter - x.FirstParameter)) Vector (-0.7071067811865475, -0.7071067811865476, 0.0) Since it is a circle Returns: Vector: representing the third derivative to the Edge at the given location along its length (or extrapolated length) Float = curvatureAt(paramval) - Get the curvature at the given parameter [First|Last] if defined Vector = centerOfCurvatureAt(float pos) - Get the center of curvature at the given parameter [First|Last] if defined Set the tolerance for the edge. Vertex = firstVertex(Orientation=False) Returns the Vertex of orientation FORWARD in this edge. If there is none a Null shape is returned. Orientation = True : taking into account the edge orientation Vertex = lastVertex(Orientation=False) Returns the Vertex of orientation REVERSED in this edge. If there is none a Null shape is returned. Orientation = True : taking into account the edge orientation Discretizes the edge and returns a list of points. The function accepts keywords as argument: discretize(Number=n) => gives a list of 'n' equidistant points discretize(QuasiNumber=n) => gives a list of 'n' quasi equidistant points (is faster than the method above) discretize(Distance=d) => gives a list of equidistant points with distance 'd' discretize(Deflection=d) => gives a list of points with a maximum deflection 'd' to the edge discretize(QuasiDeflection=d) => gives a list of points with a maximum deflection 'd' to the edge (faster) discretize(Angular=a,Curvature=c,[Minimum=m]) => gives a list of points with an angular deflection of 'a' and a curvature deflection of 'c'. Optionally a minimum number of points can be set which by default is set to 2. Optionally you can set the keywords 'First' and 'Last' to define a sub-range of the parameter range of the edge. If no keyword is given then it depends on whether the argument is an int or float. If it's an int then the behaviour is as if using the keyword 'Number', if it's float then the behaviour is as if using the keyword 'Distance'. Example: import Part e=Part.makeCircle(5) p=e.discretize(Number=50,First=3.14) s=Part.Compound([Part.Vertex(i) for i in p]) Part.show(s) p=e.discretize(Angular=0.09,Curvature=0.01,Last=3.14,Minimum=100) s=Part.Compound([Part.Vertex(i) for i in p]) Part.show(s) Wire = split(paramval) Splits the edge at the given parameter values and builds a wire out of it Args: paramval (float or int): The parameter value along the Edge at which to split it e.g: x = Part.makeCircle(1, FreeCAD.Vector(0,0,0), FreeCAD.Vector(0,0,1), 0, 90) y = x.derivative3At(x.FirstParameter + 0.5 * (x.LastParameter - x.FirstParameter)) Returns: Wire: wire made up of two Edges isSeam(Face) - Checks whether the edge is a seam edge. Set or get the tolerance of the vertex Returns the cartesian length of the curve Returns a 2 tuple with the range of the primary parameter defining the curve. This is the same as would be returned by the FirstParameter and LastParameter properties, i.e. (LastParameter,FirstParameter) What the parameter is depends on what type of edge it is. For a Line the parameter is simply its cartesian length. Some other examples are shown below: Type Parameter --------------------------------------------------------------- Circle Angle swept by circle (or arc) in radians BezierCurve Unitless number in the range 0.0 to 1.0 Helix Angle swept by helical turns in radians Returns the start value of the range of the primary parameter defining the curve. What the parameter is depends on what type of edge it is. For a Line the parameter is simply its cartesian length. Some other examples are shown below: Type Parameter ----------------------------------------------------------- Circle Angle swept by circle (or arc) in radians BezierCurve Unitless number in the range 0.0 to 1.0 Helix Angle swept by helical turns in radians Returns the end value of the range of the primary parameter defining the curve. What the parameter is depends on what type of edge it is. For a Line the parameter is simply its cartesian length. Some other examples are shown below: Type Parameter ----------------------------------------------------------- Circle Angle swept by circle (or arc) in radians BezierCurve Unitless number in the range 0.0 to 1.0 Helix Angle swept by helical turns in radians Returns the 3D curve of the edge Returns true if the edge is closed Returns true if the edge is degenerated Returns the mass of the current system. Returns the center of mass of the current system. If the gravitational field is uniform, it is the center of gravity. The coordinates returned for the center of mass are expressed in the absolute Cartesian coordinate system. Returns the matrix of inertia. It is a symmetrical matrix. The coefficients of the matrix are the quadratic moments of inertia. | Ixx Ixy Ixz 0 | | Ixy Iyy Iyz 0 | | Ixz Iyz Izz 0 | | 0 0 0 1 | The moments of inertia are denoted by Ixx, Iyy, Izz. The products of inertia are denoted by Ixy, Ixz, Iyz. The matrix of inertia is returned in the central coordinate system (G, Gx, Gy, Gz) where G is the centre of mass of the system and Gx, Gy, Gz the directions parallel to the X(1,0,0) Y(0,1,0) Z(0,0,1) directions of the absolute cartesian coordinate system. Returns Ix, Iy, Iz, the static moments of inertia of the current system; i.e. the moments of inertia about the three axes of the Cartesian coordinate system. Computes the principal properties of inertia of the current system. There is always a set of axes for which the products of inertia of a geometric system are equal to 0; i.e. the matrix of inertia of the system is diagonal. These axes are the principal axes of inertia. Their origin is coincident with the center of mass of the system. The associated moments are called the principal moments of inertia. This function computes the eigen values and the eigen vectors of the matrix of inertia of the system.