Google Summer of Code/2009/Project Ideas

Revision as of 20:09, 12 March 2008 by Sean (talk | contribs) (clean up last year's)

The list of possible projects below is in no way complete but it should serve as a good starting point for volunteers that would like to become BRL-CAD developers. In addition to the tasks below, you may also want to consider some of these ideas.

Feel free to contact us if you have any questions, corrections, comments, or ideas of your own that you'd like to suggest.


Do you have an idea of your own? Let us know and maybe we'll like it too. We're very open to new ideas, areas of academic research, industry applications, and any other ways that may help get you hooked on BRL-CAD development. Just remember that BRL-CAD is a solid modeling CAD suite so keep that in mind when scoping your project. The idea needs to fit in with our project goals and it needs to be specific.


  • Passion for the task being suggested
  • Buy-in from one of the existing developers

OpenGL Application Framework

BRL-CAD includes a graphical solid modeler named MGED as well as an experimental refactoring named Archer, both written in Tcl/Tk. While MGED is extensively powerful in its modeling capabilities and is in production use, new users and developers tend to want something different. They want an interface that doesn't require extensive training and expert knowledge before they can use it. A redesign of the modeling interface is under way and this project idea focuses on one piece of that effort.

The goal would be to implement the application framework for communicating with a geometry service back-end. Rather than reimplementing existing functionality, the framework would be an extendible plug-in-based client-server system that would utilize existing binaries and editing functionality exposed in MGED. More to the point, this task entails creating that (basic) client-server communications API using an OpenGL client front-end.


  • Strong knowledge of C++ and object oriented design
  • Ability to implement according to provided design criteria

CSG evaluation of Boundary Representation objects

One of the current primary BRL-CAD development efforts is the complete integration of hybrid model support. BRL-CAD leverages the Rhino openNURBS library to provide fundamental BREP support but there is still much work to be done to evaluate BREPs. This task basically involves implementing BREP-on-BREP CSG evaluation routines (resulting in a new evaluated BREP object). If you get done fast enough, you could also work on implementing the routines that generate a BREP for all of our implicit primitives which would bring us one step closer towards providing complete dual-representation support.


  • Familiarity with C/C++ programming
  • Strong math skills
  • Familiarity with CSG operations, BREP/n-Manifold geometry, and explicit spline surface geometry representations
  • (optional) Strong familiarity with implicit geometric representations

Universal geometry converter API

With more than 30 geometry importers and exporters, including several that are of paramount importance to CAD communities such as IGES and DXF, BRL-CAD contains a multitude of converters that can be chained together to go to and from various formats. This task would involve refactoring the existing converters into a clean "universal" geometry converter and API that could read and write from any of the supported formats as run-time plugins. If you have more time, you can always start work on a new converter too.


  • Familiarity with C or C++ programming
  • Ability to understand and refactor existing code


This task is pretty simple on the surface: implement annotations. This effectively amounts to implementing a new primitive in BRL-CAD that can be associated with other objects for providing annotation information. Annotations would allow the modeler to leave notes and draw simple diagrams around geometry during the modeling process where the annotations are either fixed with respect to the view or align with the object(s) they refer to (if any). There are design considerations as to whether you can ray-trace an annotation as well as how to most effectively display them. It would be awesome if users could interactively edit their annotations through the GUI.


  • Strong familiarity with C
  • Ability to implement within an existing framework

Constraints and Parametrics

BRL-CAD does not presently provide the means to specify values that are undetermined or otherwise dependent calculations. That is to say that there is no support for constraints and parametrics such that a modeler can define a sphere such that the sphere's radius necessarily maintains tangency with a given planar surface. This task would focus on implementing basic support for this feature in the BRL-CAD geometry format.


  • Strong familiarity with C
  • Ability to implement within an existing framework

Object-oriented geometry engine API

BRL-CAD includes four libraries that provide the basis for our core geometry engine: libbu, libbn, librt, and libwdb. These libraries all expose a C API to various geometry processing capabilities, yet there are frequent requests for an object-oriented C++ and/or Java API to this same information. This task would focus on providing an object-oriented interface in either C++ or Java (or both, swig?). The library should be designed such that it provides features similar to those found in other commercial geometry engines such as the ACIS engine and leverages as much of those libraries as possible for the implementation detail.


  • Strong familiarity with C and C++
  • Strong familiarity with object oriented API design
  • Ability to review an existing procedural API

Web-based Solid geometry model repository

This task focuses on creating a web interface to a geometry repository where the community can store and exchange geometric models in any of the supported BRL-CAD formats. The website could be written such that it integrates with an existing content management system (e.g. Drupal extension), wiki (e.g. Mediawiki extension), or could be custom with the appropriate design plan. The site would need to provide a relatively easy means for users to upload models and have those models be indexed, categorized, searched, converted, and downloaded through the website interface.


  • Strong web development skills
  • (optional)Familiarity with Drupal or Mediawiki customization and/or module development

STEP parser integration

Several BRL-CAD developers are working on implementing a full STEP converter. This task is a big effort given the complexity of the STEP standard (ISO 10303). This task focuses on one of the fundamental components of the STEP converter which is to update and integrate the NIST STEP AP 21 parser with BRL-CAD. The NIST sources as well as copies of the STEP standard can be provided as needed. If that is too easy, the next step is jumping in on AP 203 and AP 214 !


  • Familiarity with C and/or C++ programming
  • Ability to integrate with and update an existing code library
  • Familiarity with writing a robust parser
  • Ability to tolerate bloated ISO standards

IGES importer/exporter enhancements

IGES is one of the most prevalent CAD geometry file formats used to exchange geometry data between CAD systems. BRL-CAD inludes extensive support for IGES, but only up to version 5.0 whereas the current/final version of IGES was 5.3 and there are non-final versions beyond that. This task would make the changes necessary to the existing IGES importer and exporter to fully support the latest IGES standard, possibly modifying the converter to simultaneously support multiple formats.


  • Familiarity with C programming
  • Strong ability to review and improve existing code