PySide2 Embed Paraview

This is an experimental project to embed a Paraview render window into a PySide2 Qt GUI. The goal is to explore the feasibility of embedding a Paraview view into a Qt application (via PySide2) and controlling it through the already-existing Paraview/Python interface.

Technologies used, and a brief explanation along with them.

• Qt 5.9.1
  • Also tested with Qt 5.6.2.
• Python 2.7
  • The desired target is 2.7, but I am interested in exploring Python 3.5+ support.
• PySide2
  • Python 2.7 bindings to Qt5. Provides shiboken2, which will be used to generate a Qt widget library accessible to Python.

Setup/Prerequisites/Building

The following instructions were tested on vanilla Ubuntu 16.0.4-2 after updating all packages.

CMake

First and foremost, install cmake!

Qt 5.9.1

Download Qt 5.9.1 from the official Qt website. Run the installer, and note your installation path.

The remainder of this document will assume a Qt installation directory of /opt/Qt5.9.1/. This makes the Qt root directory /opt/Qt5.9.1/5.9.1/gcc_64.

ParaView

It is recommended that you use the ParaView superbuild, found here: https://gitlab.kitware.com/paraview/paraview-superbuild

Required Ubuntu packages if you don't build the superbuild.

• python-dev
• libtbb2
• libtbb-dev
• libglu1-mesa-dev
• libxt-dev

Get Paraview from the Github repository.

git clone --recursive https://github.com/Kitware/ParaView.git

Build paraview against Qt 5.9.1 and Python 2.7 as follows:

export CMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}:/opt/Qt5.9.1/5.9.1/gcc_64/lib/cmake/
export PATH=/opt/Qt5.9.1/5.9.1/gcc_64/bin/:${PATH}
export LD_LIBRARY_PATH=/opt/Qt5.9.1/5.9.1/gcc_64/lib/:${LD_LIBRARY_PATH}

mkdir ParaView/build && cd ParaView/ 

cmake -DCMAKE_BUILD_TYPE:STRING=RelWithDebInfo \
    -DPYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython2.7.so \
    -DPYTHON_EXECUTABLE=/usr/bin/python2.7 \
    -DPYTHON_INCLUDE_DIR=/usr/include/python2.7 \
    -DBUILD_TESTING:BOOL=OFF \
    -DPARAVIEW_ENABLE_CATALYST:BOOL=OFF \
    -DPARAVIEW_ENABLE_PYTHON:BOOL=ON \
    -DPARAVIEW_QT_VERSION:STRING=5 \
    -DPARAVIEW_ENABLE_WEB:BOOL=OFF \
    -DPARAVIEW_ENABLE_EMBEDDED_DOCUMENTATION:BOOL=OFF\
    -DPARAVIEW_USE_QTHELP:BOOL=OFF \
    -DVTK_RENDERING_BACKEND:STRING=OpenGL2 \
    -DVTK_SMP_IMPLEMENTATION_TYPE:STRING=TBB \
    -DVTK_PYTHON_VERSION:STRING=2 \
    -DVTK_PYTHON_FULL_THREADSAFE:BOOL=ON \
    -DVTK_NO_PYTHON_THREADS:BOOL=OFF \
    ..

time cmake --build . -- -j4

PySide2

Get pyside-setup from the git repo here: http://code.qt.io/cgit/pyside/pyside-setup.git/

git clone --recursive https://code.qt.io/pyside/pyside-setup.git

You will need to have a Clang version 3.9 or later along with any Clang development headers. Refer to the README.md for pyside-setup for more info. You will also need to export LLVM_INSTALL_DIR to the llvm root directory. An example is provided below.

A quick way to get Clang 3.9 (used in this writeup) is as follows:

wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
sudo apt-add-repository "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.9 main"
sudo apt-get update

sudo apt-get install clang-3.9 lldb-3.9 libclang-3.9-dev
export LLVM_INSTALL_DIR=/usr/lib/llvm-3.9/

Install Python dependencies:

pip install sphinx

Once you have the git repo cloned, a few modifcations are required to support Qt 5.9.

cd pyside-setup/
git checkout 5.9
cd sources/pyside2-tools && git checkout 5.9 && cd ../../
cd sources/pyside2-examples && git checkout 5.9 && cd ../../

Now compile!

export MAKEFLAGS='-j4'
export CXXFLAGS='-std=c++11'
python setup.py install --qmake=/opt/Qt5.9.1/5.9.1/gcc_64/bin/qmake --reuse-build --ignore-git

This will install pyside2 and shiboken2 into /path/to/pyside-setup/pyside2_install/py2.7-qt5.9.1-64bit-release/.

pyside2-embed-paraview

libpvWidget is the C++ library that wraps Paraview. pvpyBinding is the C++/Shiboken2 configuration sub-project for generating the Python wrapper.

After cloning this repository, build the project. You will need to look over each and every path to make sure they correspond to the installations on your machine. A sample build script build.sh.example is provided, but must be edited before it will work.

cd pyside2-embed-paraview/
mkdir build/ && cd build/

# include qt5.9.1 modules
export CMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}:/opt/Qt5.9.1/5.9.1/gcc_64/lib/cmake/
export PATH=/opt/Qt5.9.1/5.9.1/gcc_64/bin/:${PATH}
export LD_LIBRARY_PATH=/opt/Qt5.9.1/5.9.1/gcc_64/lib/:${LD_LIBRARY_PATH}

# include paraview
PARAVIEW_ROOT=$HOME/ParaView/build/
export CMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}:$PARAVIEW_ROOT/lib/cmake/
export PATH=$PARAVIEW_ROOT/bin:${PATH}
export LD_LIBRARY_PATH=$PARAVIEW_ROOT/lib/:${LD_LIBRARY_PATH}

# include pyside2/shiboken2
export CMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}:/path/to/pyside-setup/pyside2_install/py2.7-qt5.9.1-64bit-release/lib/cmake/

cmake \
  -DGENERATOR=/path/to/pyside-setup/pyside2_install/py2.7-qt5.9.1-64bit-release/bin/shiboken2 \
  -DPYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython2.7.so \
  -DPYTHON_INCLUDE_DIR=/usr/include/python2.7 \
  ..

make -j4

If all compiles, you should have a pypvBinding.so located in build/pypvBinding/pypvBinding.so. That is your python module!

Running

A sample run script run.sh.example is provided. Please edit the file and set all paths that correspond to your setup.

Issues

If you run into issues with running the app, it may be related to incorrect library search paths, or a protobuf issue I have yet to resolve.