occBasicSamples

Very basic OpenCASCADE examples that compile on Linux on the commandline with g++. A .stl, .wrl and .stp file is written into a file which can be imported and viewed by a program like blender, MeshLab, FreeCAD or view3dscene for example. The purpose of these tiny example programs is to show the most basic usage of the Open CASCADE 3D library possible, thus flattening the learning curve for a beginner (like me).

Installation

Debian 8.9 (jessie) was used as operating system.

• OpenCascade (https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt_dev_guides__building.html)
  • Building 3rd party libraries (https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt_dev_guides__building_3rdparty_linux.html):

     root> apt-get install g++ cmake cmake-curses-gui
     root> apt-get install tcllib tklib tcl-dev tk-dev libfreetype-dev libxt-dev libxmu-dev libxi-dev libgl1-mesa-dev libglu1-mesa-dev libfreeimage-dev libtbb-dev libgl2ps-dev 
     root> apt-get install doxygen graphviz
     root> apt-get install libqt4-dev libvtk6-dev libvtk6-qt-dev
    

  • Download OpenCascade from https://www.opencascade.com/content/latest-release. You must create an account in order to do so.
  • Configure (https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt_dev_guides__building_cmake.html):

     user> mkdir opencascade
     user> cd opencascade/
     user> cp ~/Downloads/opencascade-7.1.0.tgz .
     user> tar -xvzf opencascade-7.1.0.tgz
     user> mkdir install
     user> mkdir build
    

  • remove the lines containing "vtkRenderingFreeTypeOpenGL" from the files TKIVtk/EXTERNLIB and TKIVtkDraw/EXTERNLIB or u will get an linker error ( see: https://www.opencascade.com/content/compataility-latest-versions-vtk)

     user> fgrep -irns vtkRenderingFreeTypeOpenGL ../opencascade-7.1.0/src/
     	     ../opencascade-7.1.0/src/TKIVtk/EXTERNLIB:17:vtkRenderingFreeTypeOpenGL
     	     ../opencascade-7.1.0/src/TKIVtkDraw/EXTERNLIB:23:vtkRenderingFreeTypeOpenGL
    

     user> cd build && ccmake ../opencascade-7.1.0/
    

    • Adapt and configure the variables as you need them.
    • Press the c key several times in order to solve all dependencies and generate the makefiles with the g-key then.
    • Here is what i have changed: > INSTALL_DIR ../install
      > 3RDPARTY_SKIP_DOT_EXECUTABLE OFF > INSTALL_DOC_Overview ON
      > INSTALL_FREETYPE ON
      > INSTALL_SAMPLES ON
      > INSTALL_TCL ON
      > INSTALL_TEST_CASES ON
      > INSTALL_TK ON
      > USE_FREEIMAGE ON
      > USE_GL2PS ON
      > USE_TBB ON
      > USE_VTK ON
  • Compile:

     user> make
    

  • Install:
    • Link tcl8.6 to tcl8 if you get an that errormessage that tcl8 cannot be found: root> ln -s /usr/lib/x86_64-linux-gnu/tcl8.6/ /usr/lib/x86_64-linux-gnu/tcl8

     user> make install
    

  • Add the OpenCascade libraries to your library path:

     root> cd /etc/ld.so.conf.d/
     root> echo '/path_to/opencascade/install/lib' > opencascade.conf
     root> ldconfig
    

• occBasicSamples

   user> git clone https://github.com/quirxi/occBasicSamples.git
   user> cd occBasicSamples/src
   user> rm include lib path_to_OpenCascade_*
   user> ln -s ../../opencascade/install/lib/ lib
   user> ln -s ../../opencascade/install/include/ include
   user> cd Box
   user> make
   		g++ -c -pipe -O3 -std=c++11 -Wall -W -g -D_REENTRANT -I../include/opencascade -o main.o main.cpp
   		g++  -o aBox.exe main.o -L../lib   -lTKernel -lTKPrim -lTKTopAlgo -lTKSTL -lTKVRML -lTKBRep -lTKG3d -lTKMesh
   user> ./aBox.exe 
   user>  ls -a
   		.  ..  aBox.exe  aBox.stl  aBox.wrl  main.cpp  main.o  Makefile
  

Available examples

Up to now there are examples for following basic shapes available:

Box:

Circle:

Cone:

Cylinder:

Sphere:

Torus:

References

• https://github.com/eryar/occQt
• https://occtutorials.wordpress.com/
• http://www.creativecadtechnology.com/OCC/ShowScript?userName=gvh&groupName=demo&scriptName=MakeBottle
• https://www.opencascade.com
• https://www.opencascade.com/doc/occt-7.1.0/overview/html/index.html
• https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt_dev_guides__building_3rdparty_linux.html
• https://www.blender.org
• http://www.meshlab.net
• https://www.freecadweb.org
• https://castle-engine.sourceforge.io/view3dscene.php

Authors:

• quirxi (https://github.com/quirxi)

License

Distributed under the MIT License.