Geometry Entities¶

The pyiges.Iges class stores each individual IGES entity seperately and each entity of an pyiges.Iges object can be accessed either via indexing or by querying for a specific type of entity

>>> import pyiges
>>> from pyiges import examples
>>> iges = pyiges.read(examples.impeller)
>>> type(iges[0])
pyiges.entity.Entity

>>> lines = iges.lines()
>>> print(lines[0])
--- Line ---
----- Entity -----
110
1213
0
...
0
From point 0.0, 0.0, -997.963013157
To point 0.0, 0.0, 2.036986843

Many of the entities are not yet fully supported, and those entities are represented as a generic pyiges.geometry.Entity object. However, many entities are supported, including:

Vertex List (Type 502 Form 1)
Edge List
Loop (for specifying a bounded face for BREP geometries
Face
Circular arc
Rational B-Spline Surface
Rational B-Spline Curve
Conic Arc (Type 104)
Line
Point

Entity Definitions¶

class pyiges.entity.Entity(iges)¶

Generic IGES entity

Examples

>>> import pyiges
>>> from pyiges import examples
>>> iges = pyiges.read(examples.impeller)
>>> entity = iges[0]
>>> entity.parameters
[['314', '75.2941176470588', '75.2941176470588', '75.2941176470588', '']]

>>> print(entity)
----- Entity -----
314
1
0
Default
0
None
None
0
200
0
8
1
0

class pyiges.geometry.Point(iges)¶

IGES Point

property coordinate¶: Coordinate of the point as a numpy array

to_vtk()¶

Point represented as a pyvista.PolyData Mesh

Returns: mesh – pyvista mesh
Return type: pyvista.PolyData

property x¶: X coordinate

property y¶: Y coordinate

property z¶: Z coordinate

class pyiges.geometry.Line(iges)¶

IGES Straight line segment

property coordinates¶: Starting and ending point of the line as a numpy array

to_vtk(resolution=1)¶

Line represented as a pyvista.PolyData Mesh

Returns: mesh – pyvista mesh
Return type: pyvista.PolyData

class pyiges.geometry.ConicArc(iges)¶

Conic Arc (Type 104) Arc defined by the equation: A*x**2 + B*x*y + C*y**2 + D*x + E*y + F = 0

with a Transformation Matrix (Entity 124). Can define an ellipse, parabola, or hyperbola.

class pyiges.geometry.RationalBSplineCurve(iges)¶

Rational B-Spline Curve IGES Spec v5.3 p. 123 Section 4.23 See also Appendix B, p. 545

to_vtk(delta=0.01)¶: Set evaluation delta (controls the number of curve points)

class pyiges.geometry.RationalBSplineSurface(iges)¶

Rational B-Spline Surface

Examples

>>> import pyiges
>>> from pyiges import examples
>>> iges = pyiges.read(examples.impeller)
>>> bsurfs = igs.bspline_surfaces()
>>> bsurf = bsurfs[0]
>>> print(bsurf)
    Rational B-Spline Surface
    Upper index of first sum:        3
    Upper index of second sum:       3
    Degree of first basis functions: 3
    Degree of second basis functions: 3
    Open in the first direction
    Open in the second direction
    Polynomial
    Periodic in the first direction
    Periodic in the second direction
    Knot 1: [0. 0. 0. 0. 1. 1. 1. 1.]
    Knot 2: [0. 0. 0. 0. 1. 1. 1. 1.]
    u0: 1.000000
    u1: 0.000000
    v0: 1.000000
    v1: 128.000000
    Control Points: 16

>>> bsurf.control_points
array([[-26.90290533, -16.51153913,  -8.87632351],
       [-25.85182035, -15.86644037, -21.16779478],
       [-25.99572556, -15.95476156, -33.51982653],
       [-27.33276363, -16.77536276, -45.77299513],
       [-28.23297477, -14.34440426,  -8.87632351],
       [-27.12992455, -13.78397453, -21.16779478],
       [-27.28094438, -13.86070358, -33.51982653],
       [-28.6840851 , -14.57360111, -45.77299513],
       [-29.29280315, -12.03305788,  -8.87632351],
       [-28.14834588, -11.56293146, -21.16779478],
       [-28.3050348 , -11.62729699, -33.51982653],
       [-29.76084756, -12.22532372, -45.77299513],
       [-30.06701039,  -9.61104189,  -8.87632351],
       [-28.89230518,  -9.2355426 , -21.16779478],
       [-29.05313537,  -9.28695263, -33.51982653],
       [-30.54742519,  -9.76460843, -45.77299513]])

control_points()¶: Control points

property flag1¶: Closed in the first direction

property flag2¶: Closed in the second direction

property flag3¶

Polynominal

False - rational True - polynomial

property flag4¶: First direction periodic

property flag5¶: Second direction Periodic

property k1¶: Upper index of first sum

property k2¶: Upper index of second sum

property knot1¶: First Knot Sequences

property knot2¶: Second Knot Sequences

property m1¶: Degree of first basis functions

property m2¶: Degree of second basis functions

to_geomdl()¶: Return a geommdl.BSpline.Surface

to_vtk(delta=0.025)¶

Return a pyvista.PolyData Mesh

Parameters: delta (float, optional) – Resolution of the surface. Higher number result in a denser mesh at the cost of compute time.
Returns: mesh – pyvista mesh
Return type: pyvista.PolyData

Examples

>>> mesh = bsurf.to_vtk()
>>> mesh.plot()

property u0¶: Start first parameter value

property u1¶: End first parameter value

property v0¶: Start second parameter value

property v1¶: End second parameter value

property weights¶: First Knot Sequences

class pyiges.geometry.CircularArc(iges)¶

Circular Arc

Type 100: Simple circular arc of constant radius. Usually defined with a Transformation Matrix Entity (Type 124).

to_vtk(resolution=20)¶

Circular arc represented as a pyvista.PolyData Mesh

Returns: mesh – pyvista mesh
Return type: pyvista.PolyData

class pyiges.geometry.Face(iges)¶: Defines a bound portion of three dimensional space (R^3) which has a finite area. Used to construct B-Rep Geometries.

class pyiges.geometry.EdgeList(iges)¶: Provides a list of edges, comprised of vertices, for specifying B-Rep Geometries.

class pyiges.geometry.VertexList(iges)¶: Vertex List (Type 502 Form 1)