While googling the net, I found this remarkable piece. This is a patent application from 2010, and from the drawings, it seems that the inventor had the ‘revolutionary’ idea of calculating some adaptive depth bias based on the depth map to improve shadow mapping.
The noteworthy part of the story is, that the official research, the patent clerk apparently turned up my ShaderX4 article from 2006, as can be seen here further down on the page. The page also states that the application has been abandoned. So, maybe the existence of this article has prevented a patent on shadow maps, or at least discouraged the issuer to pursue the application. In either case, let’s hope it stays that way!
We can draw two conclusions from this.
- Conclusion 1: ShaderX seems to be recognized by the EPO as a source of state of the art.
- Conclusion 2: If you have an idea, write about and publish it! It doesn’t matter if it is just a blog post. If it can be tracked down, this can prevent a patent on the same idea in the future!