3d graphics patents
For a well-documented example, see OpenGL.
Cone-step mapping
The technique of cone-step mapping is encumbered up by US5355442.[1]
This was noticed in 2006 by members of the gamedev.net forum.[2]
A summary was posted in 2010 to the "OpenGL 4.0 preview driver" forum, on AMDZone.com:
Unfortunately Cone-Step Mapping is patent encumbered for the next year or two. The original author of it was informed of the infringed patent after quite a bit of development. I think the patent is on data processing for MRI/CTscan data, and also fails the obviousness test. I won't elaborate, but given the mathematics of raytracing a randomly rough surface, many others have come up with the same equations, then had to dumb things down to avoid that patent.
by Montaray Jack on Sat Apr 03, 2010 4:56 am[3]