Re: approximation to pow(n,x)?
"Simon Fenney" <[email protected]>
| Newsgroups | gmane.games.devel.algorithms |
|---|---|
| Message-ID | <[email protected]> |
Jon Watte wrote: > Nathaniel Hoffman wrote: >> lowly cosine power - it's not completely physically meaningless. If >> you are using Blinn-Phong (N dot H, which is much to be preferred >> over original Phong - R dot L), then using a cosine power is >> equivalent to >> > > Except you already have the reflection vector for your environment > mapping, so why not re-use it? > Ignoring any issues on what is more "physically accurate", I always assumed that Blinn introduced his model because if you.. A) assume your view angle didn't change (i.e. viewer is an infinite distance away) and B) your lights are 'parallel/infinitely far away' ...then the method is much cheaper than the "Phong" method. I think these sort of assumptions are valid approximations for software rendering, which was the norm at the time. Once these restrictive conditions are lifted however, it seems to me that the original Phong method is far cheaper. Simon ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ GDAlgorithms-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list