POV-Ray: Newsgroups: povray.advanced-users: Square roots of negative numbers in isosurfaces?: Re: Square roots of negative numbers in isosurfaces?

POV-Ray : Newsgroups : povray.advanced-users : Square roots of negative numbers in isosurfaces? : Re: Square roots of negative numbers in isosurfaces?		Server Time 30 Jul 2024 12:29:25 EDT (-0400)

From: Ron Parker
Date: 18 Jan 2000 08:16:10
Message: <3884679a@news.povray.org>

On Tue, 18 Jan 2000 00:16:47 -0500, Matt Giwer wrote:
>    I am sure there are but I do not know of any smooth function (not discontinuous
like
>1 and 0 binary) that has any problems with evaluation at any point but real zero. And
>with a smooth function the small value always works.

Well, sqrt(x) is undefined for all x<0.  But somehow the isosurface patch
manages to deal with that.  I think the reason is that the processors we 
usually run it on keep going on getting a NaN result.  Try running it on 
an alpha and see how quickly it manages to crash.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

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