Comments on: Understanding Quake’s Fast Inverse Square Root http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/ Learning shouldn't hurt. Let's share the insights that made difficult ideas click. Mon, 15 Mar 2010 17:10:21 +0000 http://wordpress.org/?v=2.8.4 hourly 1 By: Kalid http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-263220 Kalid Thu, 26 Nov 2009 13:41:53 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-263220 @saurabh: Thanks! I had trouble understanding the paper at first, writing down my thoughts helped make the ideas click a bit more :). @saurabh: Thanks! I had trouble understanding the paper at first, writing down my thoughts helped make the ideas click a bit more :) .

]]> By: saurabh http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-263197 saurabh Thu, 26 Nov 2009 10:30:10 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-263197 Thanks for putting the time and effort to give a very clear explanation. I tried to read the paper at first, but your explanation provided adequate explanation for someone who wants to get a first hand understanding that piece of code. Keep up the good work. Thanks for putting the time and effort to give a very clear explanation. I tried to read the paper at first, but your explanation provided adequate explanation for someone who wants to get a first hand understanding that piece of code. Keep up the good work.

]]> By: Paul Duffy http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-251712 Paul Duffy Sat, 05 Sep 2009 16:42:39 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-251712 Bit of a correction. Normalising is not actually a 'fancy term for division'. A vector has an exact length of 1, that is, sqrt(x^2+y^2+z^2) = 1. The normalisation process takes a scalar, like a vector but with no definition of how long it should be, and makes it a vector of the same direction. It's important for things like lighting in computer graphics (you've heard of normal maps, right?), even phong shading wouldn't work without it. Bit of a correction. Normalising is not actually a ‘fancy term for division’. A vector has an exact length of 1, that is, sqrt(x^2+y^2+z^2) = 1. The normalisation process takes a scalar, like a vector but with no definition of how long it should be, and makes it a vector of the same direction.

It’s important for things like lighting in computer graphics (you’ve heard of normal maps, right?), even phong shading wouldn’t work without it.

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