NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/comp/sys/next/programm/5350

Internet Message Format | 1992-07-29 | 1.5 KB

Path: sparky!uunet!ogicse!reed!lydgate
From: [e-mail] (Chris Lydgate)
Newsgroups: comp.sys.next.programmer
Subject: Renderman surface mapping problem
Message-ID: <[e-mail]>
Date: 30 Jul 92 08:43:34 GMT
Article-I.D.: reed.1992Jul30.084334.9893
Organization: Reed College, Portland, OR
Lines: 37


Help!

I've been soundly defeated in my effort to do surface mapping in the
3DKit.  The Renderman Companion (TRC) says this is done by using a
surface shader. But the shaders in /NextLibrary/Shaders which look
like candidates, ie "texmap.slo", I can't get them to work.

In general, I can successfully tell an N3DShader to read a .slo file,
set its instance variables, and then associate that shader with an
N3DShape.  For many shaders, this works perfectly.

The "texmap.slo" shader has a "texturemap" i-var, which (I guess) is
supposed to be set to a texture file.  However, setting this i-var
never seems to
/NextLibrary/Textures..

TRC (p 253) lists a fragment for doing what I want (mapping an
image file onto a surface) but it makes use of an imaginary shader
called "mytexture".  It says that such shaders
are easy to write, but  does not say how.

Basically, I'm wondering:

1) How do I map a texture file onto a surface using the 3DKit?

2) If there's no standard shader for doing this, how could I write
one?

3) How can I create a texture file from, say, a TIFF file?  (I know
about RiMakeTexture(), but the documentation is vague about file
formats.)

Thanks in advance,

Chris Lydgate
[e-mail]