Interial-Visual
Sample example: http://students.asl.ethz.ch/upl_pdf/459-report.pdf
Appearance Based Loop Closure: https://code.google.com/p/rtabmap/
State Estimation for Aggressive Flight in GPS-Denied Environments Using Onboard Sensing: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6225295
BlenSor: https://github.com/mgschwan/blensor
VoxCAD: http://www.voxcad.com/tutorials
POVRay extra utilities: http://www.oyonale.com/apropos.php?section=apropos&page=1&lang=en
ArchiveTexture: http://archivetextures.net/?page=1561
POVray colour chart: http://www.buckosoft.com/~dick/pov/colors.php