John Carmack, technical boss at id Software, has been busy re-writing a segment of the DOOM 3 source code before they release the code for free.

Apparently there are some surrounding one particular graphical technique used in the DOOM 3 engine known as Carmack's Reverse.

This is a shadow stencilling technique that Carmack discovered in 1997 but Creative Labs own the the patent for the graphical algorithm.

Carmack himself explained on Twitter: "Lawyers are still skittish about the patent issue around 'Carmack's Reverse', so I am going to write some new code for the 3 release."

Thanks ShackNews.

By Ewan Aiton