Re: [Plib-devel] LoadASE problem.

[Steve B. <sjb...@ai...>]

Dave McClurg wrote:
> 
> Christian wrote:
> 
> >I tried to compile a new plib checkout, but MSVC complaind about a few
> >parts in the ASE load/save routines
> 
> Thanks for checking this out.  I added the fixed to other changes i'm making.
> I noticed the plib.dsw/dsp in CVS is missing the new files and ssgContext.cxx.
> i'll send Steve the changes for a commit later today

Yes - I don't posess a single byte of Microsoft software - so I can't maintain
the MSVC build setup...or any other non-Makefile-based scheme for that
matter.

However, if someone wants to send me those project files, I'll be happy
to commit them.

> >Using the save.cxx SSG example with loading the tuxedo.ac and saving it
> >then as tuxedo.ase I get
> >
> >*MATERIAL_AMBIENT -431602080.000000 -431602080.000000 -431602080.000000
> >*MATERIAL_DIFFUSE -431602080.000000 -431602080.000000 -431602080.000000
> >
> >in all materials. This doesn't lok right (it looks like some unitialized
> >floats). Is that correct?
> >
> 
> correct.  AC format specifies rgb,amb,emis,and spec where as ASE specifies amb,diff,spec.

Emission isn't used much anyway - most of the time it's just
easier to disable GL_LIGHTING - which has much the same effect.

> ssgLoadAC does this:
> 
>   st -> setMaterial ( GL_SPECULAR, mat -> spec ) ;
>   st -> setMaterial ( GL_EMISSION, mat -> emis ) ;
> 
> and ssgLoadASE does this:
> 
>   st -> setMaterial ( GL_AMBIENT, mat -> amb ) ;
>   st -> setMaterial ( GL_DIFFUSE, mat -> diff ) ;
>   st -> setMaterial ( GL_SPECULAR, mat -> spec ) ;
> 
> therefore, when you load AC and save ASE you get undefined amb and diff.
> before i fix this, i'd like to understand it more fully.  anyone want to comment on
> how the state should be initialized for unknown properties?

It's messy because of glColorMaterial.

Personally, my application software sets glColorMaterial to pick up the
diffuse/ambient colours from the glColor() call and I totally ignore
the emission/specular from the file - forcing them to black and white
respectively.

Added to which, I code the entire ssgSimpleState into the application and
use the texture map name from the model file to find the material in the
application.

This means that I can't just pick up any random model off the web and
toss it (unmodified) into my game - but that's a pretty silly thing
to expect anyway.  Games have to manage how much texture they consume
and stuff like that - so anything more complex than the very simplest
game will need to do something similar to this.

-- 
Steve Baker                  http://web2.airmail.net/sjbaker1
sjb...@ai... (home)  http://www.woodsoup.org/~sbaker
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