Visualizing Constructive Solid Geometry (CSG)


In recent years, tools like graphviz have made automatic graphical layout of graph structures in images both practical and useful. Traditionally, geometric hierarchies in BRL-CAD databases have been visualized either as lists or trees, and those methods continue to be the primary geometry browsing methods.

This task would follow up on work from 2012 using automatic graph layout libraries to produce a graph based visualization of the structure of .g databases:

The task is not simply to generate images of graphical geometry hierarchies - that is relatively straightforward and can be done with scripts - but to design graphical, interactive widgets that utilize graph algorithms to interactively display geometry structure in useful, intuitive and interactive ways (tying changes in wireframe 3D renderings to selection or de-selection of nodes in a graph display of .g geometry, for example). Some progress was made in 2012, but there is a lot more that can be done.

Our current interfaces use the Tk toolkit, but Qt would also make an interesting toolkit for this sort of work.

Proposals should include specific ideas (mockups and example layouts are a good way to convey graphical ideas).


  • src/tclscripts
  • src/tclscripts/mged
  • src/tclscripts/archer
  • src/libtclcad

Potentially useful libraries must be under a compatible (BSD, MIT, LGPL2) license - (work so far has been done using the Adaptagrams library):


  • Familiarity with Tcl/Tk and/or Qt
  • Familiarity with C/C++
  • Comfortable understanding of graphs (will be working with graph libraries)

Past Efforts