POV-Ray : Newsgroups : povray.general : ATTN: Nieminen Juha Server Time
9 Aug 2024 19:37:07 EDT (-0400)
  ATTN: Nieminen Juha (Message 1 to 1 of 1)  
From: John VanSickle
Subject: ATTN: Nieminen Juha
Date: 13 Jun 2000 19:24:25
Message: <3946C264.9A0BF8FE@erols.com>
I replied to your e-mail to me about the PCM4 format, but your mail
server believes that my mail server is insecure, and bounced the
message.  So here it is, again.

Nieminen Juha wrote:
> 
>   Hi!
>   Since you have been more or less closely related to the PCM format
> and related macros (SSS), I thought that I could consult you (as well
> as Chris) about the new PCM format with full support for mesh2.

Okay.

>   First of all I would like to ask if you have any good example pov
> files with mesh2's with uv-mapping and preferably also with textures
> and texture indices.

No examples on hand, sorry.

>   (Btw. I have one question regarding to the ReadPCM() macro of your
> SSS:  Why does it ignore the normal vectors of the input?)

When I first learned about the Loop surface subdivision technique, the
source I learned it from did not give any means of keeping edges sharp;
hence everything was smoothed, and whatever normal vectors were
inherited would have to be replaced with other data anyway.  Around the
beginning of the year I came across some more info that showed how
sharp edges could be preserved with each subdivision.  From this I
deduced that by writing the proper normal vectors, the sharp edges
could be saved in a type 1 PCM file, and then retrieved by analyzing
the normal vectors.  Consequently, when the IRTC gives me breathing
room (not much luck there this round!), I'll be supporting this in both
the SSS and the Blue Booby Mesh Modeler (which I am re-writing).  Next
I'll be adding individual triangle texturing (which is supported,
albeit with a bug, in POV v3.1).  When UV-mapping is supported in
the official release of POV-Ray, I'll be adding that as well.

>   Below is a mail I sent to Chris. It's a proposition for the new PCM
> format for mesh2 support. Feel free to send me any comments and
> propositions you may have (you can send it to Chris as well so that he
> can follow the situation).

I'll look it over, thanks.  I'm pretty sure that I can deal with
whatever you two settle on; right now I'm content to see how UV-mapping
is implemented in the scene code in 3.5 before I try to write any
macros for it.

Thanks,
John
-- 
ICQ: 46085459


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