POV-Ray : Newsgroups : povray.advanced-users : error: Cannot layer over a patterned texture. : Re: error: Cannot layer over a patterned texture. Server Time
30 Jul 2024 14:29:19 EDT (-0400)
  Re: error: Cannot layer over a patterned texture.  
From: Ron Parker
Date: 29 Nov 1999 08:56:37
Message: <38428615@news.povray.org>
On Mon, 29 Nov 1999 00:01:10 -0500, Nathan Kopp wrote:
>
>Ron Parker <ron### [at] povrayorg> wrote...
>> By the way, one side-effect of this is that POV seems to trace too many
>rays
>> for some scenes.  The following scene traces three rays per pixel (one eye
>> ray plus one transmitted ray for each of the plain textures in the
>> interpolation.)  I suppose you could call that a bug.
>
>Not totally a bug.  If each layer has a different normal & the interior has
>an IOR, you'd want it to use different rays.  An optimization would be to
>re-use the result from a refraction or reflection if the previous layer
>already shot it.

Would you want it to?  Or would you average the normals as you would with a 
normal_map?  That is, should a texture_map of two different normals have 
the same result as a normal_map of the same two normals, or should it be as 
it is now? (This is the second example in the post you replied to.)

-- 
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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