An Introduction To New Developers

BRL-CAD is exceptionally capable yet lacking in usability. Flexibility is one of our greatest assets and detriments. Interface is our biggest problem. Addressing our fundamental usability issues are heavily tied to our mathematical geometry representation format and is something we’re in the middle of fixing (Wu’s GSoC project is actually a critical piece to that puzzle).

Qt (a cross-platform complete development framework for creation of amazing user interfaces) has been in our development roadmap for many years. We expect we’ll probably have initial useful user capability in late 2014. Vlad’s GSoC project involves implementing a Qt display manager, which is also a critical piece of that puzzle.

Moreover, Archer (the new GUI; under development) is a step in a complex refactoring process. It’s predominantly a mechanism for abstracting the useful logic from within MGED (present GUI) into reusable library form. Specifically, this gave us the GED library, which is letting us reuse tremendous amounts of useful code that was previously held within MGED. That library supports the development of a new Qt-based interface.

Only certain types of geometry can be represented in one of the explicit forms that OpenGL supports (points, lines, polygons). OpenGL does not have inherent support for many types of geometry representation formats, particularly any of the implicit forms, volumetric forms, level sets, NURBS boundary representation, and more. There are some conversion libraries that help describe such data in a form that OpenGL can display, but it is not "inherent" capability.

We’ve been working on NURBS infrastructure to make wireframes not be the default but there is no plan to remove wireframes as some users prefer them, some models cannot be visualized in full without them. When most people say shaded display, they usually think of OpenGL, Direct3D, games, other modeling systems, etc. Those systems are driven by polygons (triangles). To have that style of shaded display, you have to have polygons. We do not have a robust method for getting polygons. NURBS gives us a robust method.

When we can 1) convert any geometry to NURBS, 2) evaluate any booleans, and 3) tessellate NURBS robustly, it will be possible to have robust shaded displays for all geometry. #1 was finished last year primarily thanks to Cliff and Wu. #3 was finished just this year primarily due to Keith. Work on #2 is underway and is scheduled to be finished in 2013.

We all are here to help make BRL-CAD better. How to go about making those improvements is key. Having background understanding helps to do that effectively without completely wasting time. It would be best to understand what the current roadmap already looks like to know about what is or is not already happening.