From rssfeeds@jmason.org Mon Oct 7 12:05:20 2002 Return-Path: Delivered-To: yyyy@localhost.example.com Received: from localhost (jalapeno [127.0.0.1]) by jmason.org (Postfix) with ESMTP id 34ED716F78 for ; Mon, 7 Oct 2002 12:03:58 +0100 (IST) Received: from jalapeno [127.0.0.1] by localhost with IMAP (fetchmail-5.9.0) for jm@localhost (single-drop); Mon, 07 Oct 2002 12:03:58 +0100 (IST) Received: from dogma.slashnull.org (localhost [127.0.0.1]) by dogma.slashnull.org (8.11.6/8.11.6) with ESMTP id g9780mK23287 for ; Mon, 7 Oct 2002 09:00:48 +0100 Message-Id: <200210070800.g9780mK23287@dogma.slashnull.org> To: yyyy@example.com From: gamasutra Subject: A Non-Integer Power Function on the Pixel Shader Date: Mon, 07 Oct 2002 08:00:48 -0000 Content-Type: text/plain; encoding=utf-8 X-Spam-Status: No, hits=-936.1 required=5.0 tests=AWL,DATE_IN_PAST_03_06,T_NONSENSE_FROM_40_50 version=2.50-cvs X-Spam-Level: URL: http://www.newsisfree.com/click/-0,8613675,159/ Date: 2002-10-06T18:12:45+01:00 This feature, excerpted from Wolfgang Engel's ShaderX book from Wordware Publishing, presents a simple shader trick that performs a good per pixel approximation of a non-integer power function. The technique works for input values between 0 and 1 and supports large exponents. The presented shader does not require any texture look-up and is scalable, making it possible to spend more instructions in order to decrease the error or to reach greater exponents.