Article <v0s1ok$2okf4$3@dont-email.me>

Warning: mysqli::__construct(): (HY000/1203): User howardkn already has more than 'max_user_connections' active connections in D:\Inetpub\vhosts\howardknight.net\al.howardknight.net\includes\artfuncs.php on line 21
Failed to connect to MySQL: (1203) User howardkn already has more than 'max_user_connections' active connections
Warning: mysqli::query(): Couldn't fetch mysqli in D:\Inetpub\vhosts\howardknight.net\al.howardknight.net\index.php on line 66
Article <v0s1ok$2okf4$3@dont-email.me>

Deutsch English Français Italiano

<v0s1ok$2okf4$3@dont-email.me>

View for Bookmarking (what is this?)
Look up another Usenet article

Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.arch
Subject: Re: Short Vectors Versus Long Vectors
Date: Wed, 1 May 2024 00:18:29 -0000 (UTC)
Organization: A noiseless patient Spider
Lines: 21
Message-ID: <v0s1ok$2okf4$3@dont-email.me>
References: <v06vdb$17r2v$1@dont-email.me> <0D7YN.12641$oA33.7712@fx34.iad>
	<e9aa636b6b12f1ac0af12946151219f4@www.novabbs.org>
	<pycYN.33914$iMKd.26920@fx12.iad> <v0rtm6$2o1mj$5@dont-email.me>
	<66c323063468ebc28ce3b5ae8d28c2ac@www.novabbs.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 01 May 2024 02:18:29 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="ad302c900c5acc5104cba5a9dbf60c1f";
	logging-data="2904548"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+HYLDOtDGMjojrHCBomEeR"
User-Agent: Pan/0.155 (Kherson; fc5a80b8)
Cancel-Lock: sha1:TfvmESjVFkzIzBW06RL4FvgmavI=
Bytes: 2220

On Tue, 30 Apr 2024 23:56:03 +0000, MitchAlsup1 wrote:

> Then contemplate for an instant that one would want SIMD instructions
> for Complex numbers and Hamiltonian Quater[n]ions......

Quaternions yeah! Interesting that they actually predated vector algebra 
<https://www.youtube.com/watch?v=M12CJIuX8D4> (from the wonderful “Kathy 
Loves Physics & History” channel), and then the mathematicians realized 
that it was a bit simpler to separate out the components and deal with 
them separately, rather than carry them around all the time. Some of the 
“old guard” resisted this move ...

And now they’ve made a comeback in computer graphics, for representing 
rotations, particularly of armature “bones” used in posing and animating 
characters.

I’m not sure you really need SIMD instructions for quaternions, though. 
Consider that the typical use of such instructions is to process millions 
or even billions of data items (e.g. pixels, maybe even geometry 
coordinates for complex models), whereas the number of bones in an 
armature is maybe a few thousand at most.