POV-Ray : Newsgroups : povray.binaries.images : ExplainationPlease...?? : Re: ExplainationPlease...?? Server Time
16 Aug 2024 20:28:21 EDT (-0400)
  Re: ExplainationPlease...??  
From: Florian Pesth
Date: 25 Jan 2002 15:04:40
Message: <3c51ba58@news.povray.org>
> The computation is more cumbersome (although there is a trick to memorize
it
> using a determinant, but I won't state it):
Maybe there's a more easy (?) way to memorize the cross product. It's called
the "cyclic minus anticyclic" rule. The idea is, that you count forward
(cyclic) for the first term and backwards (anticyclic) for the "minus term".
So for the first component you count 1- "2" - "3" using "2" and "3" for the
indices of the vectors minus 1 - "3" - "2" (backwards). Same way for the
second 2 - "3" - "1" minus 2 - "1" - "3" and the third 3 - "1" - "2" minus
3 - "2" - "1".
So this is cyclic: 1 - 2 - 3 - 1 - 2 - 3 and this is anticyclic 3 - 2 - 1 -
3 - 2 - 1.
Hope that nobody's more confused (by my english?), then forget it ;)
Best regards,
Florian


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