pyIGES

Python IGES reader with basic functionality to read an IGES file and convert some entities to a pyvista or vtk mesh.

This module can read in and perform basic parsing of all entities and can perform additional parsing and geometry visualization of the following entities:

• 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

Installation

pyiges is offered in a "full" variant including the conversion features and a "pure" parsing module variant. The pure variant has no conversion features, no dependencies to pyvista,geomdl, and can be installed by removing the [full] specificator from the following commands.

Install with pip using:

.. code::

pip install pyiges[full]

Otherwise, if you want the bleeding edge version, feel free to clone this repo and install with:

.. code:: bash

git clone https://github.com/pyvista/pyiges cd pyiges pip install .[full]

Note that the square brackets might need to be escaped or quoted when using zsh.

Usage

The pyiges module can read in many entities as raw text, but only NURBS surfaces and bsplines can be converted to pyvista meshes.

.. code:: python

import pyiges
from pyiges import examples

# load an example impeller
iges = pyiges.read(examples.impeller)

# print an invidiual entity (boring)
print(iges[0])

# convert all lines to a vtk mesh and plot it
lines = iges.to_vtk(bsplines=True, surfaces=False, merge=True)
lines.plot(color='w', line_width=2)

# convert all surfaces to a vtk mesh and plot it
mesh = iges.to_vtk(bsplines=False, surfaces=True, merge=True, delta=0.05)
mesh.plot(color='w', smooth_shading=True)
# control resolution of the mesh by changing "delta"

# save this surface to file
mesh.save('mesh.ply')  # as ply
mesh.save('mesh.stl')  # as stl
mesh.save('mesh.vtk')  # as vtk

Lines

.. image:: https://github.com/pyvista/pyiges/raw/main/docs/images/impeller_lines.png


Surfaces

.. image:: https://github.com/pyvista/pyiges/raw/main/docs/images/impeller_surf.png

Acknowledgments

Substantial code was obtained from or inspired by https://github.com/cfinch/IGES-File-Reader

IGES reference definitions were obtained from Eclipse IGES Wiki <https://wiki.eclipse.org/IGES_file_Specification#Rational_B-Spline_Curve_.28Type_126.29>_,