BRL-CAD provides several ways to model 3D geometry including a graphical tool named mged, another named archer, and various ways to create geometry using scripts. We use 3D models for development and to showcase our features. You can learn the basics of 3D modeling in just an hour or two.

This task involves modeling a gerotor. This is basically a cool pump. Your job is to model it natively using any of BRL-CAD's tools (i.e., don't model it in something else and import) using 3D primitives and Boolean operations (i.e., without using 2D sketch entities or polygons).

The gear set should be accurately modeled in such a way that it can be printed using a 3D printer. This means that the model should have regions defined for each part and no overlaps (use rtcheck and/or gqa commands to verify). Create one top-level combination to group everything together.

• http://en.wikipedia.org/wiki/Gerotor
• http://www.pumpschool.com/principles/gerotor.asp
• https://www.youtube.com/watch?v=nodDVMl-nLA
• Introduction to MGED at http://brlcad.org/wiki/Documentation

• Submit your model as a .g file (BRL-CAD's geometry file format) and a rendered PNG image. You can run "rt -s1024 -o your_rendering.png your_geometry.g your_top_level_object" to create a PNG rendering of your model.