Google Summer of Code/2009/Project Ideas

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.

<Your Idea Here>

Do you have an idea of your own? Let us know and maybe we'll like it too.

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

New solid modeler application framework

BRL-CAD includes a GUI-based 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 to generate and manipulate detailed solid models that often cannot be managed by even the biggest commercial packages, the interface leaves much to be desired for new users. The interface requires extensive training and expert knowledge prior to use. A redesign of the modeling interface is under way. The focus of this project would be to implement the application foundation for visualizing existing geometry using an extendible plug-in-based client-server framework.


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

CSG evaluation of Boundary Representation objects

BRL-CAD is using the openNURBS library to provide fundamental BREP enhancements to BRL-CAD. As BRL-CAD includes extensive support for arbitrary CSG operations, this task requires the implementation of BREP-on-BREP CSG evaluation routines (resulting in a new evaluated BREP object).


  • Familiarity with C/C++ programming
  • Strong math skills
  • Familiarity with CSG operations, BREP/n-Manifold geometry, and explicit spline surface geometry representations

Universal geometry converter API

With more than 30 geometry importers and exporters, including several that are of paramount prevalence in the 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 API that could read and write from any of the supported formats as run-time plugins.


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

Geometry storage server daemon

This task involves creating a geometry server that responds to network requests for registered geometry, providing an efficient and scalable IP interface. This geometry server will be later integrated with the modeling tools for local operations as well as remote distributed network operations and will need to be designed to accommodate accordingly. The daemon will need to provide a push and pull interface for query- and subscription-based access to model data.


  • Strong familiarity with C/C++
  • Familarity with server/daemon network programming

Dual-representation geometry support

Originally a CAD package entirely focused around implicit geometric representations, BRL-CAD has become a hybrid modeling system. To facilitate geometric conversions from implicit CSG to other forms such as NURBS and triangulated forms, BRL-CAD needs to have additional information encoded into the existing implicit primitives. This effectively amounts to writing a routine for each existing primitive that provides an in-memory explicit spline surface representation from the existing implicit form.


  • Strong familiarity with implicit and spline surface explicit geometric representations
  • Strong familiarity with n-manifold structures and solid geometry
  • Strong foundations in mathematics
  • Ability to implement within an existing framework
  • Familiarity with C


This task is pretty simple on the surface: implement annotations. This effectively amounts to implementing a new optionally view-specific 2D primitive in BRL-CAD that can be associated with other objects. This allows 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).


  • 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 consist of the core geometry engine: libbu, libbn, librt, and libwdb. These libraries all expose a C API to geometry processing capabilities, yet there are frequent requests for a C++ and/or Java API to this same information. This task would focus on providing an object-oriented in either C++ or Java (or both) using an existing implementation effort as a starting point. The library should be designed such that it provides features similar to those found in other commercial geometry engines such as the ACIS engine.


  • Strong familiarity with C and C++
  • Strong familiarity with object oriented API design

Web-based solid geometry model repository

This task focuses on creating a web interface to a geometry model repository where the community may store and exchange geometry models in any of the supported BRL-CAD formats. The website should be written such that it integrates with the Drupal content management system and provides a relatively simplified means for users to upload models and have those models be indexed, searchable, and downloadable through the website interface.


  • Familiarity with Drupal customization and/or module development
  • Familiarity with PHP programming and web development

STEP parser integration

Several BRL-CAD developers are working on implementing a full STEP converter over the next two years. This task is a monumental effort given the complexity of the STEP standard (ISO 10303). This task focuses on one of the fundamental compoentns 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.


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

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. This task would make the changes necessary to the existing IGES importer and exporter to fully support the IGES standard.


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