BRL-CAD

BRL-CAD is an open source, cross-platform solid modeling system built around a hybrid CSG and B-REP kernel for unambiguous 3D geometry. It provides interactive geometry editing, high-performance ray tracing for rendering and geometric analysis, a system performance benchmark suite, and geometry libraries for application developers. The project has been under active development for more than 30 years and is distributed in both binary and source code form.

The package runs on common operating system environments including BSD, Linux, Solaris, Mac OS X, and Windows. Its Archer/MGED interface is an alpha-stage update to the graphical geometry editor, adding an integrated graphical tree view, a single-window framework, drag-and-drop geometry editing, information panels, shortcut buttons, improved polygonal mesh and 2D sketch editing, level-of-detail wireframes, and NURBS shaded display support. The current release also includes ray tracing improvements such as CPU thread affinity locking, expanded volume and surface area calculations, and more robust NURBS evaluation, along with robustness improvements to the STEP, Patch, and 3DM importers.

BRL-CAD is aimed at developers, writers, artists, and other contributors, as well as users working on geometric modeling and analysis. It is released under OSI-approved open source license terms and is provided free of charge, with no separate paid editions, trials, or seat-based or usage-based packaging described.