Welcome

Welcome to Open CASCADE Technology (OCCT), a software development platform providing services for 3D surface and solid modeling, CAD data exchange, and visualization. Most of OCCT functionality is available in the form of C++ libraries. OCCT can be best applied in development of software dealing with 3D modeling (CAD), manufacturing / measuring (CAM) or numerical simulation (CAE).

http://www.opencascade.org

Copyrights

http://www.opencascade.com

License

Open CASCADE Technology is free software; you can redistribute it and / or modify it under the terms of the GNU Lesser General Public License (LGPL) version 2.1, with additional exception.

Alternatively, Open CASCADE Technology may be used under the terms of Open CASCADE commercial license or contractual agreement.

Note that Open CASCADE Technology is provided on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND. The entire risk related to any use of the OCCT code and materials is on you. See the license text for formal disclaimer.

Trademark information

You are hereby informed that all software is a property of its respective authors and is protected by international and domestic laws on intellectual property and trademarks. Should you need further information, please directly contact the authors.

CAS.CADE and Open CASCADE are registered trademarks of OPEN CASCADE S.A.S.

Linux is a registered trademark of Linus Torvalds.

Windows is a registered trademark of Microsoft Corporation in the United States and other countries.

Mac and the Mac logo, OpenCL and the OpenCL logo, are trademarks of Apple Inc., registered in the U.S. and other countries.

Acknowledgements

The following parties are acknowledged for producing tools which are used within Open CASCADE Technology libraries or for release preparation.

You are hereby informed that all rights to the software listed below belong to its respective authors and such software may not be freely available and/or be free of charge for any kind of use or purpose. We strongly recommend that you carefully read the license of these products and, in case you need any further information, directly contact their authors.

Qt is a cross-platform application framework that is widely used for developing application software with graphical user interface (GUI). Qt is free and open source software distributed under the terms of the GNU Lesser General Public License. In OCCT Qt is used for programming samples. If you need further information on Qt, please, refer to Qt Homepage (http://qt.digia.com).

Tcl is a high-level programming language. Tk is a graphical user interface (GUI) toolkit, with buttons, menus, listboxes, scrollbars, and so on. Taken together Tcl and Tk provide a solution to develop cross-platform graphical user interfaces with a native look and feel. Tcl/Tk is under copyright by Scriptics Corp., Sun Microsystems, and other companies. However, Tcl/Tk is an open source, and the copyright allows you to use, modify, and redistribute Tcl/Tk for any purpose, without an explicit license agreement and without paying any license fees or royalties. To use Tcl/Tk, please refer to the Licensing Terms (http://www.tcl.tk/software/tcltk/license.html).

Robert Boehne has developed GNU Autoconf, Automake and Libtool scripts and makefiles for the Open CASCADE project http://sourceforge.net/projects/autoopencas/, which became an initial groundwork for the build scripts based on respective GNU tools (autoconf, automake and libtool) in Open CASCADE Technology version 4.0. These scripts are now maintained by the OPEN CASCADE company.

GL2PS is developed by Christophe Geuzaine and others. It is optionally used by OCCT to export content of OpenGL scene to vector graphics formats (PS, PDF, EMF, SVG). The library is licensed under GL2PS LICENSE http://www.geuz.org/gl2ps/COPYING.GL2PS Version 2, November 2003.

FreeType 2 is developed by Antoine Leca, David Turner, Werner Lemberg and others. It is a software font engine that is designed to be small, efficient, highly customizable and portable while capable of producing high-quality output (glyph images). This product can be used in graphic libraries, display servers, font conversion tools, text image generation tools, and many other products.

FreeType 2 is released under two open-source licenses: BSD-like FreeType License and the GPL.

Intel(R) Threading Building Blocks (TBB) offers a rich and complete approach to expressing parallelism in a C++ program. It is a library that helps you to take advantage of multi-core processor performance without having to be a threading expert. Threading Building Blocks is not just a threads-replacement library. It represents a higher-level, task-based parallelism that abstracts platform details and threading mechanisms for scalability and performance. TBB is available under GPLv2 license with the runtime exception.

Open CASCADE Technology WOK module on Windows also makes use of LGPL-licensed C routines regexp and getopt, taken from GNU C library.

OpenGL is an industry standard API for 3D graphics used by OCCT for implementation of 3D viewer. OpenGL specification is developed by the Khronos group, http://www.khronos.org/opengl/. OCCT code includes header file glext.h obtained from Khronos web site.

OpenCL (Open Computing Language) is open, royalty-free standard for cross-platform, parallel programming of modern processors, optionally used by OCCT for ray tracing. OpenCL specification is developed by the Khronos group, http://www.khronos.org/opencl/. The implementations of OpenCL are available from Apple, AMD, NVIDIA, Intel, and other vendors. OpenCL Installable Client Driver (ICD) Loader is a library provided by Khronos group which allows dispatching OpenCL calls to underlying implementation.

Doxygen developed by Dimitri van Heesch is open source documentation system for C++, C, Java, Objective-C, Python, IDL, PHP and C#. This product is used in Open CASCADE Technology for automatic creation of Technical Documentation from C++ header files. If you need further information on Doxygen, please refer to http://www.stack.nl/~dimitri/doxygen/index.html.

Graphviz is open source graph visualization software developed by John Ellson, Emden Gansner, Yifan Hu and Arif Bilgin. Graph visualization is representiation of structured information as diagrams of abstract graphs and networks. This product is used together with Doxygen in Open CASCADE Technology for automatic creation of Technical Documentation (generation of dependency graphs). Current versions of Graphviz are licensed on an open source basis under The Eclipse Public License (EPL) (http://www.graphviz.org/License.php).

Inno Setup is a free script-driven installation system created in CodeGear Delphi by Jordan Russell. In OCCT Inno Setup is used to create Installation Wizard on Windows. It is licensed under Inno Setup License (http://www.jrsoftware.org/files/is/license.txt).

FreeImage is an Open Source library supporting popular graphics image formats, such as PNG, BMP, JPEG, TIFF, and others used by multimedia applications. This library is developed by Hervé Drolon and Floris van den Berg. FreeImage is easy to use, fast, multithreading safe, compatible with all 32-bit or 64-bit versions of Windows, and cross-platform (works both with Linux and Mac OS X). FreeImage is optionally used by OCCT to work with images, on conditions of the FreeImage Public License (FIPL) (http://freeimage.sourceforge.net/freeimage-license.txt).

MikTEX is up-to-date implementation of TeX/LaTeX and related programs for Windows. It is used for generation of User and Developer Guides in PDF format. See http://miktex.org for information on this tool.

Adobe Systems, Inc. provides Adobe Reader, which can be used to view files in Portable Document Format (PDF).

Documentation

OCCT documentation is provided in several forms:

This overview provides general description of OCCT structure, functionality, modules, and features. It is available in HTML format (generated by Doxygen) and includes User and Developer Guides. The sources of this documentation are contained in dox subdirectory of OCCT sources (plain text format is used, with mixed MarkDown / Doxygen syntax mark-up).
User and Developer Guides describing in details OCCT modules and development tools are also available in Adobe Portable Document Format (PDF). To read this format, you need Adobe Acrobat Reader, which is a freeware and can be downloaded from the Adobe site.
Full reference documentation covering all OCCT classes generated automatically by Doxygen software is provided in HTML format, in a separate package. Reference documentation is presented in Modules –> Toolkits –> Packages –> Classes logic structure with cross-references to all OCCT classes and complete in-browser search by all classes.

See OCCT Documentation Guide for details on OCCT documentation system.

Generation of HTML documentation

To generate HTML documentation from sources contained in dox subdirectory, you need to have Tcl and Doxygen 1.8.4 (or above) installed on your system.

In Tcl prompt, cd to OCCT root folder and run

tclsh> source dox/start.tcl

On Windows you can also run batch script gendoc.bat.

Generation of reference documentation

Reference documentation can be generated with help of WOK tool that is available for download from www.opencascade.org and dev.opencascade.org sites.

Prerequisites:

Doxygen version 1.8.4 or higher
Graphviz version 2.28.0 or higher

Run WOK (cd <WOK_INSTALL_DIR>/site folder):

Using WOK TCL shell: > wok_tclsh.sh
Using Emacs editor: > wok_emacs.sh

In the WOK prompt, step into your workbench:

  > wokcd <your workbench>

In your workbench, use wgendoc command with –h argument to get information about arguments of wgendoc command:

  > wgendoc -h

then run wgendoc command with required arguments, for instance:

  > wgendoc -output=d:/occt/doc {-m=Draw Visualization}

Requirements

Open CASCADE Technology is designed to be highly portable and is known to work on wide range of platforms (UNIX, Linux, Windows, Mac OS X). Current version is officially certified on Windows (IA-32 and x86-64), Linux (x86-64) and MAC OS X (x86-64) platforms.

The tables below describe the recommended hardware and software configurations for which OCCT is certified to work.

Linux

Operating System	Mandriva 2010, CentOS 5.5, CentOS 6.3, Fedora 17, Fedora 18, Ubuntu-1304, Debian 6.0*
Minimum memory	512 MB, 1 GB recommended
Free disk space (complete installation)	600 MB approx.
Video card	See Graphic cards
Graphic library	OpenGL 1.1+ (OpenGL 2.1+ is recommended)
C++	GNU gcc 4.0. - 4.7.3.
TCL (for testing tools)	Tcltk 8.5 or 8.6 http://www.tcl.tk/software/tcltk/8.6.html
Qt (for demonstration tools)	Qt 4.6.2 http://qt.nokia.com/downloads
Freetype (for text rendering)	freetype-2.4.11 http://sourceforge.net/projects/freetype/files/
FreeImage (optional, for support of common 2D graphic formats)	FreeImage 3.15.4 http://sourceforge.net/projects/freeimage/files
gl2ps (optional, for export contents of OCCT viewer to vector graphic files)	gl2ps-1.3.8 http://geuz.org/gl2ps/
Intel TBB (optional, for multithreaded algorithms)	TBB 3.x or 4.x http://www.threadingbuildingblocks.org/
OpenCL (optional, for ray tracing visualization)	OpenCL SDK (usually one provided by vendor of your graphic card) or OpenCL ICD Loader by Khronos group, http://www.khronos.org/registry/cl

Debian 60 64 bit is a platform used for regular testing of contributions

Windows

Operating System	Windows 8 / 7 SP1 / Vista SP2 / XP SP3
Minimum memory	512 MB, 1 GB recommended
Free disk space (complete installation)	600 MB approx.
Video card	See Graphic cards
Graphic library	OpenGL 1.1+ (OpenGL 2.1+ is recommended)
C++	Microsoft Visual Studio: 2005 SP1, 2008 SP1*, 2010 SP1, 2012 Update 3, 2013 Intel C++ Composer XE 2013 SP1
TCL (for testing tools)	ActiveTcl 8.5 or 8.6 http://www.activestate.com/activetcl/downloads
Qt (for demonstration tools)	Qt 4.6.2 http://qt.nokia.com/downloads
Freetype (OCCT Text rendering)	freetype-2.4.11 http://sourceforge.net/projects/freetype/files/
FreeImage (Support of common graphic formats)	FreeImage 3.15.4 http://sourceforge.net/projects/freeimage/files
gl2ps (Export contents of OCCT viewer to vector graphic file)	gl2ps-1.3.8 http://geuz.org/gl2ps/
Intel TBB (optional, for multithreaded algorithms)	TBB 3.x or 4.x http://www.threadingbuildingblocks.org/
OpenCL (optional, for ray tracing visualization)	OpenCL SDK (usually one provided by vendor of your graphic card) or OpenCL ICD Loader by Khronos group, http://www.khronos.org/registry/cl

VC++ 9 32-bit is used for certification of contributions and for building binary package of official release of OCCT on Windows.

MAC OS X

Operating System	Mac OS X 10.9 Mavericks / 10.8 Mountain Lion / 10.7 Lion / 10.6.8 Snow Leopard
Minimum memory	512 MB, 1 GB recommended
Free disk space (complete installation)	600 MB approx.
Video card	See Graphic cards
Graphic library	OpenGL 1.1+ (OpenGL 2.1+ is recommended)
C++	XCode 3.2 or newer (4.x is recommended)
Qt (for demonstration tools)	Qt 4.6.2 http://qt.nokia.com/downloads
Freetype (OCCT Text rendering)	freetype-2.4.11 http://sourceforge.net/projects/freetype/files/
FreeImage (Support of common graphic formats)	FreeImage 3.15.4 http://sourceforge.net/projects/freeimage/files
gl2ps (Export contents of OCCT viewer to vector graphic file)	gl2ps-1.3.8 http://geuz.org/gl2ps/
Intel TBB (optional, for multithreaded algorithms)	TBB 3.x or 4.x http://www.threadingbuildingblocks.org/
OpenCL (optional, for ray tracing visualization)	Native OpenCL 1.2.8

Graphic cards

For 3d viewer, graphic card or software implementation supporting OpenGL 1.1 or above is required. OpenGL 2.1+ is highly recommended. For ray tracing, hardware implementation of OpenCL 1.1+ is required.

The following table lists graphic cards tested to work with OCCT.

Graphic card	Driver/GL/GLSL/CL version	OS	OpenGL (fixed pipeline)	OpenGL (shaders)	OpenCL (ray tracing)
NVIDIA GeForce GT 610, 630M, 640	Driver 311.44, GL 4.3.0, GLSL 4.30	Windows 7 64 bit	OK	OK	OK
Intel(R) HD Graphics 3000	GL 3.1.0, GLSL 1.40	Windows 7 64 bit	OK	OK	none
RadeOn 9600	GL 2.1.8454, GLSL 1.20		OK	bad	none
AMD/ATI RadeOn HD 7870	Driver 6.14.10.12002, GL 4.2.12002, GLSL 4.20	Windows 7 64-bit	OK	OK	OK
Mesa 7.8.2 Windows GDI Driver*	GL 2.1, GLSL version 1.20	Mac OS X 10.6 / OS X 10.9	OK	artifacts	none
NVIDIA GeForce 320		Mac OS X 10.6 / OS X 10.9	OK	OK	OK on OSX 10.6, bad on OSX 10.9
NVIDIA GeForce 6600 GT	GL 2.1.2, GLSL 1.20	Windows XP 32-bit	OK	OK	none
Apple software OpenGL		Mac OS X 10.6 / OS X 10.9	OK	OK	OK

Mesa implementation of OpenGL is used for certification testing of OCCT

Installation

In most cases you need to rebuild OCCT on your platform (OS, compiler) before using it in your project, to ensure binary compatibility. See Building OCCT from sources for instructions on building OCCT from sources on supported platforms.

Using Windows installer

On Windows Open CASCADE Technology can be installed with binaries precompiled by Visual C++ 2008 with installation procedure.

Recommendation:

If you have a previous version of OCCT installed on your station, and you do not plan to use it along with the new version, you might want to uninstall the previous version (using Control Panel, Add/Remove Programs) before the installation of this new version, to avoid possible problems (conflict of system variables, paths, etc).

Attention: For full installation OCCT requires approximately 650 Mb of disk space, but during the installation process you will need 1,2 Gb of free disk space.

OCCT installation with reference documentation requires 1,4 Gb on disk.

Download the OCCT installer from OPEN CASCADE web site using the link. you have been provided
Launch the installer and follow the instructions.

The includes and binaries of third-party libraries necessary for building and launching OCCT are included into binary distribution (built with Visual C++ 2008). When the installation is complete, you will find the directories for 3rd party products (some might be absent in case of custom installation) and the main OCCT directory:

The contents of the OCCT-6.7.0 directory (called further "OCCT root", or $CASROOT) are as follows:

The directory tree

adm This folder contains administration files, which allow rebuilding OCCT;
adm/cmake This folder contains files of CMake building procedure;
adm/msvc This folder contains Visual Studio projects for Visual C++ 2005, 2008 and 2010, which allow rebuilding OCCT under Windows platform in 32 and 64-bit mode;
data This folder contains CAD files in different formats, which can be used to test the OCCT functionality;
doc This folder contains OCCT documentation in HTML and PDF format;
dox This folder contains sources of OCCT documentation in plain text (MarkDown) format;
drv This folder contains source files generated by WOK (private header files and instantiations of generic classes);
inc This folder contains all OCCT header files;
samples This folder contains sample applications.
src This folder contains OCCT source files. They are organized in folders, one per development unit;
tests This folder contains scripts for OCCT testing.
win32/vc9 This folder contains executable and library files built in optimize mode for Windows platform by Visual C++ 2008;

Environment Variables

To run any Open CASCADE Technology application you need to set the environment variables.

On Windows

You can define the environment variables with env.bat script located in the $CASROOT folder. This script accepts two arguments to be used: the version of Visual Studio (vc8 - vc12) and the architecture (win32 or win64).

The additional environment settings necessary for compiling OCCT libraries and samples by Microsoft Visual Studio can be set using script custom.bat located in the same folder. You might need to edit this script to correct the paths to third-party libraries if they are installed on your system in a non-default location.

Script msvc.bat can be used with the same arguments for immediate launch of Visual Studio for (re)compiling OCCT.

On Unix

If OCCT was built by Code::Blocks, you can define the environment variables with env_cbp.sh or custom_cbp.sh script.

If OCCT was built by Automake, you can define the environment variables with env_amk.sh or custom_amk.sh script.

The scripts are located in the OCCT root folder.

Description of system variables:

CASROOT is used to define the root directory of Open CASCADE Technology;
PATH is required to define the path to OCCT binaries and 3rdparty folder;
LD_LIBRARY_PATH is required to define the path to OCCT libraries (on UNIX platforms only);
MMGT_OPT (optional) if set to 1, the memory manager performs optimizations as described below; if set to 2, Intel (R) TBB optimized memory manager is used; if 0 (default), every memory block is allocated in C memory heap directly (via malloc() and free() functions). In the latter case, all other options except MMGT_CLEAR and MMGT_REENTRANT are ignored;
MMGT_CLEAR (optional) if set to 1 (default), every allocated memory block is cleared by zeros; if set to 0, memory block is returned as it is;
MMGT_CELLSIZE (optional) defines the maximal size of blocks allocated in large pools of memory. Default is 200;
MMGT_NBPAGES (optional) defines the size of memory chunks allocated for small blocks in pages (operating-system dependent). Default is 10000;
MMGT_THRESHOLD (optional) defines the maximal size of blocks that are recycled internally instead of being returned to the heap. Default is 40000;
MMGT_MMAP (optional) when set to 1 (default), large memory blocks are allocated using memory mapping functions of the operating system; if set to 0, they will be allocated in the C heap by malloc();
CSF_LANGUAGE is required to define the default language of messages;
CSF_DEBUG (optional, Windows only): if defined then a diagnostic message is displayed in case of an exception;
CSF_DEBUG_BOP (optional): if defined then it should specify directory where diagnostic data on problems occured in Boolean operations will be saved;
CSF_MDTVTexturesDirectory defines the directory for available textures when using texture mapping;
CSF_UnitsDefinition and CSF_UnitsLexicon should define paths to resource files Lexi_Expr.dat and Units.dat, respectively, required for support of measurement units;
CSF_SHMessage is required in order to define the path to the messages file for ShapeHealing;
CSF_XSMessage is required in order to define the path to the messages file for STEP and IGES translators;
CSF_StandardDefaults and CSF_PluginDefaults are required in order to maintain CASCADE Persistence mechanism to make possible any open/save operations with OCAF documents;
CSF_StandardLiteDefaults is required in order to maintain OCCT Persistence mechanism to make possible any open/save operations with Lite OCAF documents;
CSF_XCAFDefaults any open/save operations for XDE documents;
CSF_IGESDefaults and CSF_STEPDefaults are required for IGES and STEP translators correspondingly in order to define the path to the resource files;
CSF_XmlOcafResource is required in order to set the path to XSD resources, which defines XML grammar.
CSF_MIGRATION_TYPES is required in order to read documents that contain old data types, such as TDataStd_Shape;
TCLLIBPATH, TCL_LIBRARY, TK_LIBRARY and TIX_LIBRARY are required to allow work with DRAW and WOK.

Getting Started

Draw Test Harness

Draw is a command interpreter based on TCL and a graphical system used for testing and demonstrating OCCT modeling libraries.

Draw can be used interactively to create, display and modify objects such as curves, surfaces and topological shapes.

Scripts can be written to customize Draw and perform tests. New types of objects and new commands can be added using C++ programming language.

Draw contains:

A command interpreter based on TCL command language.
A 2D an 3D graphic viewer with support of operations such as zoom, pan, rotation and full-screen views.
An optional set of geometric commands to create and modify curves and surfaces and to use OCCT geometry algorithms.
A set of topological commands to create and modify BRep shapes and to use OCCT topology algorithms.
A set of graphic commands for view and display operations including Mesh Visualization Service.
A set of Application framework commands for handling of files and attributes.
A set of Data Exchange commands for translation of files from various formats (IGES,STEP) into OCCT shapes.
A set of Shape Healing commands: check of overlapping edges, approximation of a shape to BSpline, etc.

You can add new custom test harness commands to Draw in order to test or demonstrate a new functionality, which you are developing.

Currently DRAW Test Harness is a single executable called DRAWEXE.

Commands grouped in toolkits can be loaded at run-time thereby implementing dynamically loaded plug-ins. Thus you can work only with the commands that suit your needs adding the commands dynamically without leaving the Test Harness session.

Declaration of available plug-ins is done through special resource file(s). The pload command loads the plug-in in accordance with the specified resource file and activates the commands implemented in the plug-in.

The whole process of using the plug-in mechanism as well as the instructions for extending Test Harness is described in the Draw Test Harness.

Draw Test Harness provides an environment for OCCT automated testing system. Please, consult its Automated Testing System for details.

Remarks:

The DRAWEXE executable is delivered with the installation procedure on Windows platform only.
To start it, launch DRAWEXE executable from Open CASCADE Technology/Draw Test Harness item of the Start\Programs menu.

Experimenting with Draw Test Harness

Running Draw

On Linux:

If OCCT was built by Code::Blocks use $CASROOT/draw_cbp.sh file to launch DRAWEXE executable;
If OCCT was built by Automake use $CASROOT/draw_amk.sh file to launch DRAWEXE executable;

Draw[1]> prompt appears in the command window

Type pload ALL

On Windows:

Launch Draw executable from Open CASCADE Technology\Test Harness\Draw Test Harness item of the Start\Programs menu or Use $CASROOT\draw.bat file to launch DRAWEXE executable.

Draw[1]> prompt appears in the command window

Type pload ALL

Creating your first geometric objects

In the command window, type axo to create an axonometric view
Type box b -10 -10 -10 20 20 20 to create a cube b of size 20, parallel to the X Y Z axis and centered on the origin. The cube will be displayed in the axonometric view in wireframe mode.
Type fit to fill the viewer with the cube
Type pcylinder c 2 30 to create a cylinder c of radius 2 and height 30. The cylinder will be displayed in addition to the cube

Manipulating the view

Type clear to erase the view
Type donly c to display the cylinder only
Type donly b to display the cube only
Type hlr hlr b to display the cube in the hidden line removal mode

Running demonstration files

Type cd ../.. to return to the root directory
Type cd samples/tcl to reach the DrawResources directory
Type source <demo_file> to run the demonstration file provided with Open CASCADE. The following demonstration files are available:
- bottle.tcl
- challenge.tcl
- DataExchangeDemo.tcl
- ModelingDemo.tcl
- VisualizationDemo.tcl

Getting Help

Type help to see all available commands
Type help <command_name> to find out the arguments for a given command

Programming Samples

MFC

Visual C++ programming samples containing 10 Visual C++ projects illustrating how to use a particular module or functionality.

The list of MFC samples:

Geometry
Modeling
Viewer2d
Viewer3d
ImportExport
Ocaf
Triangulation
HLR
Animation
Convert

Remarks:

MFC samples are available only on Windows platform;
To start a sample use Open CASCADE Technology\Samples\Mfc\ item of the Start\Programs menu;
Read carefully readme.txt to learn about launching and compilation options.

See Readme for details.

Qt

OCCT contains three samples based on Qt application framework

Import Export

Import Export programming sample contains 3D Viewer and Import / Export functionality.

Tutorial

The Qt programming tutorial teaches how to use Open CASCADE Technology services to model a 3D object. The purpose of the tutorial is not to explain all OCCT classes but to help start thinking in terms of the Open CASCADE Technology.

This tutorial assumes that the user has experience in using and setting up C++. From the viewpoint of programming, Open CASCADE Technology is designed to enhance user's C++ tools with high performance modeling classes, methods and functions. The combination of these resources allows creating substantial applications.

See also: OCCT Tutorial

Voxel

This is a demonstration application showing OCCT voxel models. It also includes a set of non-regression tests and other commands for testing this functionality (accessible only through TEST pre-processor definition).

See also: Voxels User's guide