Path: chuka.playstation.co.uk!news
From: Bruce McNeish <bruce@mcneish.freeserve.co.uk>
Newsgroups: scee.yaroze.programming.3d_graphics
Subject: Re: Getting Y coord from Plane and X,Z coords
Date: Sun, 16 Jan 2000 23:27:40 +0000
Organization: PlayStation Net Yaroze (SCEE)
Lines: 48
Message-ID: <388253EC.DB41458F@mcneish.freeserve.co.uk>
References: <387FB920.1F1201B7@mcneish.freeserve.co.uk> <3883e37c.3289377294@news.playstation.co.uk>
NNTP-Posting-Host: tnt-11-234.easynet.co.uk
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 4.7 [en]C-CCK-MCD   (Win98; I)
X-Accept-Language: en

Steven,

I think the equation of a plane is

aX + bY + cZ + d = 0

If I substitute the coords for each known point on the place, the
corners

I would get 4 equation to solve to give me the equation of the plane, I
could then substitute the X and Z coords of the point required and out
should pop the Y coord?

Yes, that would work ( I think ), sorry i'm babbling.

Does this sound right to you?

Bruce

b_mcneish@yahoo.com


Steven Osman wrote:
> 
> I think that staring with the coordinates of the points on the plane
> you should be able to compute the formula of the plane.  Then it's
> just as simple as plugging in what you know, to get what you don't.
> 
> If you don't know how to derive the equation of a plane, I can look it
> up for you (I think I can at least).
> 
> Steven
> 
> On Sat, 15 Jan 2000 00:02:40 +0000, Bruce McNeish
> <bruce@mcneish.freeserve.co.uk> wrote:
> 
> >Hi all,
> >
> >I simple puzzel for you boffins to contimplate.
> >
> >I have a polygon which I know the coords of the corners(A,B,C,D).
> >
> >If I have a point that I know the X and Z coords, how do I work out the
> >Y coord of this point?
> >
> >Cheers all,
> >
> >Bruce McNeish