Article View: comp.graphics.algorithms
Article #51Re: BSP tree question
From: Nicolas Pomarede
Date: Fri, 01 Sep 1995 07:26
Date: Fri, 01 Sep 1995 07:26
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1175 bytes
Tim Wendt <tim.wendt@daytonoh.ncr.com> wrote:
>What is the test to determine if a vector is is front or behind the partition
>vector (2D only ala Doom) when building a BSP tree?
>
>I'm still confused. The dot product was described as ||u|| ||v|| cos (angle
>between the vectors). How do I find the angle between the two vectors? Is
>this the easiest approach? Thanks much!
>
you can use this to get rid of the angle and the cos:
u.v = ||u||*||v||*cos(angle)
= x1x2 + y1y2 + z1z2
where x,y,z are the respective coordinates of u and v.
------------------
Nicolas Pomarede
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Path: arc1-ca.pugleaf.net!tank.news.pipex.net!pipex!oleane!usenet From: Nicolas Pomarede <uapds1@pobox.oleane.com> Newsgroups: comp.graphics.algorithms,comp.sys.amiga.programmer,rec.games.programmer Subject: Re: BSP tree question Date: 1 Sep 1995 07:26:19 GMT Organization: Oleane - PIPEX Internatinal Message-ID: <426cir$234@Helene.OLEANE.NET> References: <DE70Io.AG6@corsair.daytonoh.attgis.com> NNTP-Posting-Host: uapds1.pobox.oleane.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 1.2b5 (Windows; I; 16bit)