[CST-2] Advanced Graphics

[Jamie Shotton]

Are you sure:
Imagine a normal vector close the origin and the direction it is
pointing.  Then move out to say 100 * the original x.  If x doesn't
change, but the normal does depend on y and z then the normal vector
will point in a much more outwards direction than before, and that is
clearly wrong as it needs to point the same way regardless of x.

J


> 
> Good point, but there is no difference between the 
> x-component of the normal at x=1 and x=2 (which is what I was 
> trying to get).
> 
> Which side of x=0 the point lies will change the sign of the 
> component, but not its magnitude.
> 
> Cheerio,
> 
> Chris
> do something lastminute.work
> 
> Chris Applegate
> Room X6, Corpus Christi College, Cambridge, CB2 1RH 
> chris@qwghlm.co.uk / www.qwghlm.co.uk / [Redacted by SRCF sysadmins on request]
> ICQ 41706821          PGP key available on request
> 
> 
> 
> > -----Original Message-----
> > From: cst-2-admin@srcf.ucam.org [mailto:cst-2-admin@srcf.ucam.org]On
> > Behalf Of Chris North
> > Sent: 1 June 2002 15:58
> > To: cst-2@srcf.ucam.org
> > Subject: RE: [CST-2] Advanced Graphics
> >
> >
> > No, the normal DOES depend on x.  For instance, what do you think 
> > happens if the intersection point changes from x=1 to 
> x=-1??  It will
> > point in opposite
> > directions with respect to x is what.  Therefore there has to
> > be a dependence.
> >
> > HTH
> >
> > --
> > Chris North
> > This address will soon be terminated, please
> > use norfus@cantab.net instead :)
> >
> >
> > _______________________________________________
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> 
> 
> 
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