Re: Altitude of a point in a triangle

On Thu, 14 Sep 2006 17:01:36 -0700, Erik Max Francis <max@[EMAIL PROTECTED]
>
wrote:
>It's still not clear to me what you're asking for.  You're talking about 
>averages, but then saying it's not the average (but then continuing to 
>talk about averages).

If I'm reading the thread right she means interpolating not weighted
averaging, i.e. trying to calculate the height of a point within the
plane of the triangle by interpolation from the triangles corners.
>
>Are you asking what the projection of P would be onto the plane defined 
>by the triangle?  In other words, if you change P's y-coordinate so that 
>it is contained within that plane, what would that y-coordinate be?

That's what I'm guessing. There may be a few ways of approaching it
depending upon what info is known, for instance if you know the point is
within the bounds of the plane (formed by the triangle) and you have the
plane's normal, use the plane equation;

http://www.lighthouse3d.com/opengl/maths/index.php?planes

....also handy for collision detection.
-- 
Alfie
<http://www.delphia.co.uk/>
Why are they called apartments, when they're all stuck together ?