pymeshfix 0.10

Repairs triangular meshes

Python/Cython wrapper of Marco Attene’s wonderful, award-winning MeshFix software. This module brings the speed of C++ with the portability and ease of installation of Python.

This software takes as input a polygon mesh and produces a copy of the input where all the occurrences of a specific set of “defects” are corrected. MeshFix has been designed to correct typical flaws present in RAW DIGITIZED mesh models, thus it might fail or produce coarse results if run on other sorts of input meshes (e.g. tessellated CAD models).

The input is assumed to represent a single CLOSED SOLID OBJECT, thus the output will be a SINGLE WATERTIGHT TRIANGLE MESH bounding a polyhedron. All the singularities, self-intersections and degenerate elements are removed from the input, while regions of the surface without defects are left unmodified.

Installation

From PyPI

pip install pymeshfix

From source at GitHub

git clone --recursive https://github.com/akaszynski/pymeshfix
cd pymeshfix
pip install .

Dependencies

Required: numpy, cython. Optional: vtk

Minimum requirements are numpy and cython. To enable plotting and several other features, vtk 5.0 or greater must be installed with Python bindings. VTK can be installed through a variety of methods. Please see http://www.vtk.org/

Tests

Test installation with the following from Python

from pymeshfix import Tests

# Test of pymeshfix without VTK module
Tests.Fix.Native()

# Performs same mesh repair while leveraging VTK's plotting/mesh loading
Tests.Fix.WithVTK()

Easy Example

This example uses the cython wrapper directly. No bells or whistles here.

from pymeshfix import _meshfix

# Read mesh from infile and output cleaned mesh to outfile
_meshfix.CleanFromFile(infile, outfile)

This example assumes the user has vertex and faces arrays in Python. Again, no bells or whistles.

from pymeshfix import _meshfix

# Generate vertex and face arrays of cleaned mesh
vclean, fclean = CleanFromVF(v, f) # v and f are numpy arrays or python lists

Fuller Examples with and without VTK

One of the main reasons to bring MeshFix to Python is to allow the library to communicate to other python programs without having to use the hard drive. Therefore, this example assumes that you have a mesh within memory and wish to repair it using MeshFix.

#Load module
from pymeshfix import meshfix

# Create object
mfobj = meshfix.MeshFixClass()
mfobj.LoadVF(v, f) # from arrays or lists
#mfobj.LoadFile(filename) # or from file
#mfobj.LoadMesh(vtkpoly) # or from a vtk.vtkPolyData object

# Plot input (if vtk is available)
mfobj.DisplayInputSurface()

# Repair input mesh
mfobj.Repair()

# Generate vtk output mesh\
mfobj.GenFixedMesh() # creates mfobj.grid

# Or, access the resulting arrays directly from the object
mfobj.vclean # numpy np.float array
mfobj.fclean # numpy np.int32 array

# View the repaired mesh
mfobj.DisplayFixedSurface()

# Save the mesh
mfobj.SaveFixedMesh('out.ply')

Alternatively, the user could use the cython wrapper of MeshFix directly if vtk is unavailable or they wish to have more control over the cleaning algorthim.

from pymeshfix import _meshfix

# Create TMesh object
tin = _meshfix.PyTMesh()

tin.LoadFile(infile)
# tin.LoadArray(v, f) # can also read arrays from memory

# Attempt to join nearby components
# tin.JoinClosestComponents()

# Fill holes
tin.FillSmallBoundaries()
print('There are {:d} boundaries'.format(tin.Boundaries())

# Clean (removes self intersections)
tin.MeshClean(max_iters=10, inner_loops=3)

# Check mesh for holes again
print('There are {:d} boundaries'.format(tin.Boundaries())

# Clean again if necessary...

# Output mesh
tin.SaveFile(outfile)
# vclean, fclean = tin.ReturnArrays() # returns numpy arrays

Algorithim and Citation Policy

To better understand how the algorithm works, please refer to the following paper:

M. Attene. A lightweight approach to repairing digitized polygon meshes. The Visual Computer, 2010. (c) Springer. DOI: 10.1007/s00371-010-0416-3

This software is based on ideas published therein. If you use MeshFix for research purposes you should cite the above paper in your published results. MeshFix cannot be used for commercial purposes without a proper licensing contract.

Copyright

MeshFix is

Copyright(C) 2010: IMATI-GE / CNR

All rights reserved.

This program is dual-licensed as follows:

1. You may use MeshFix as free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

In this case the program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License (http://www.gnu.org/licenses/gpl.txt) for more details.

2. You may use MeshFix as part of a commercial software. In this case a proper agreement must be reached with the Authors and with IMATI-GE/CNR based on a proper licensing contract.