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Re: [Manta] Reflections with Obj Files


Chronological Thread 
  • From: Thiago Ize <thiago@cs.utah.edu>
  • To: John Kichury <jjk@sgi.com>
  • Cc: "'manta@sci.utah.edu'" <manta@sci.utah.edu>
  • Subject: Re: [Manta] Reflections with Obj Files
  • Date: Tue, 23 Oct 2007 14:16:39 -0600

I found it by looking at the manta and glm source code (I learned about that today as well). Looking at the svn log, it appears that this is something that was added by us and is not standard. Sounds to me like we should document these changes somewhere...

The swig front-end for manta has a menu option for moving the light source. Other people on this list know better than me how to get that to work.

Thiago

John Kichury wrote:
Thanks. That did it.
The obj mtl spec document I have does not mention 'r'.
Do you have a pointer to a full material spec document?

Also, is it possible to move the light source?
I didn't see anything in Manta help for controlling light parameters.


Thanks,

John
-----Original Message-----
From: Thiago Ize [mailto:thiago@cs.utah.edu] Sent: Tuesday, October 23, 2007 12:42 PM
To: John Kichury
Cc: manta@sci.utah.edu
Subject: Re: [Manta] Reflections with Obj Files

I believe reflection is handled by 'r' in an mtl file. For reflections to occur you need to have an "Ns" so that manta knows to use the phong material and not lambertian (lambertian doesn't do reflections) and the 'r' to specify the amount of reflection.

For instance:

newmtl Yellow208
Ns 92.156863
Ka 0.000000 0.000000 0.000000
Kd 0.521600 0.577280 0.286080
Ks 0.250000 0.250000 0.250000
d 1.000000
r 0.4     ---- this is the important part.

Thiago

John Kichury wrote:
Hi,

Is it possible for Manta to render reflections when using obj files?
I tried increasing the material property values such as
specular and
shininess in the material library file which didn't affect
reflections.
Thanks,


John

_______________________
J o h n   K i c h u r y
Principal Systems Engineer, SGI
<jjk@sgi.com>









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