Thread: Re: [Plib-devel] DXF load/save

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I commited Wavefront OBJ import/export functions to PLIB/SSG
They only handle geometry right now
If someone can give me to a texture mapped OBJ model, i'll work on adding the texture support

Dave McClurg wrote:

> I commited Wavefront OBJ import/export functions to PLIB/SSG
> They only handle geometry right now
> If someone can give me to a texture mapped OBJ model, i'll work on
> adding the texture support

Bill Weiland <bil...@ch...> said that he was working on an SSG
loader that would be ready "probably within the next few weeks"...dunno
what happened to that.

Bill - are you listening?

AFAIK, here is the current list of who is working on
what loader/writer-wise:

.ase : Author: Dave McClurg dp...@ef...
        IMPORT Status: 80% complete & functional
        EXPORT Status: complete
        Description: ASCII Export format of 3DSMAX.
        Todo: need to support mesh animations and sub materials fully
        but works well for most models

Dave says: I am interested in writing a VRML 1.0 ascii loader if that
  makes sense.  Anyone else  actively working on VRML support?  Does
  anyone have an issue with only supporting VRML 1.0 ascii ?
------------------------------------------------------------------------
.lwo: Leath Muller <le...@gb...>

       I am going to write a file importer for PLIB (Lightwave)
       but not an exporter yet... (file extension is .lwo)
       The code has been written already (for my modeller) I
       just have to convert it to PLIB.
------------------------------------------------------------------------
             "Christopher K. St. John" <cs...@qu...>

 I've got a partially finished VRML97 loader. However, VRML97 and
VRML 1.0 are different enough so that having two different loaders
is probably reasonable.
------------------------------------------------------------------------
.pov: Author: Christian Mayer <Va...@t-...>
      IMPORT Status: never - considered impossible
      EXPORT Status: started, but currently on hold while I'm trying
                     to figure out how to write a writer for SSG as
                     the example code that I used didn't work.
      Description:   PovRay is a well known freeware raytracer.
      Note:          You'll probably need at least MegaPov or the yet
                     to come PovRay 3.5 (=> I'll use mesh2)
------------------------------------------------------------------------
.obj: Author: Bill Weiland <bil...@ch...>
      IMPORT Status: "probably within the next few weeks"
      EXPORT Status: not yet?
   ...also...
      Author: Dave McClurg <dp...@ef...>
      IMPORT Status: Geometry only - no texture
      EXPORT Status: Geometry only - no texture
      Description:   OBJ is a fairly simple ASCII model format
                     exported by Wavefront.
------------------------------------------------------------------------
.ac : Author: Steve Baker <sjb...@ai...>
        IMPORT Status: 100% complete & functional
        EXPORT Status: none
        Description: ASCII Export format of AC3D.
------------------------------------------------------------------------
.ssg : Author: Steve Baker <sjb...@ai...> 
        IMPORT Status: 100% complete & functional
        EXPORT Status: 100% complete & functional
        Description: Native binary format for SSG - supported by PPE
------------------------------------------------------------------------
.dxf : Author: Dave McClurg <dp...@ef...>
        IMPORT Status: DXF lines and faces are both supported
        EXPORT Status: DXF lines and faces are both supported
------------------------------------------------------------------------

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

Here is a jumble of PLIB thoughts:

- The trivial alias/AC3D triangle import/export was omitted from
the loader/writer list.

- I got permission from the author of IVCON, John Burkardt, to use
his code in PLIB under LGPL

- For the loaders, would the following be wise:

	if ( glIsEnabled ( GL_LIGHTING ) )
	   load normal array
	else
	   load color array

That way, you only get the data you need.  Or are there some cases
which need both?  Or is there a different way to decide which is needed?
In my game, everything will be prelit so I will leave lighting disabled
and I don't need vertex normals.

- you can make a "really nice" skybox in 3DSMAX.
i would prefer that over a skydome.
multiple cloud bands moving in different directions and heights would be
great
simulating weather (rain,snow,storms with lightning) is needed.
i have some relevant code for this stuff once GLU/SSG-Util gets started.

- I should have ASE animation code commited by end of week

- Welcome back Steve and Happy St Patricks Day!  I hope everyone has
planted their potatoes in the northern hemisphere.

Dave McClurg wrote:

> - The trivial alias/AC3D triangle import/export was omitted from
> the loader/writer list.

I can add that easily.

> - I got permission from the author of IVCON, John Burkardt, to use
> his code in PLIB under LGPL

Cool!

> - For the loaders, would the following be wise:
> 
>         if ( glIsEnabled ( GL_LIGHTING ) )
>            load normal array
>         else
>            load color array
> 
> That way, you only get the data you need.  Or are there some cases
> which need both?

You need them both under both circumstances:

  if lighting is enabled:

      You can have both per-vertex colours (using GL_COLOR_MATERIAL)
      and per-vertex normals.

  if lighting is disabled:

      You obviously need per-vertex colours - but you may also
      want something like sphere-mapped texturing which makes use
      of per-vertex normals to do cheesy environment mapping.

So, this is not a wise change.

> Or is there a different way to decide which is needed?
> In my game, everything will be prelit so I will leave lighting disabled
> and I don't need vertex normals.

Perhaps we need to add a 'hinting' mechanism for the loaders to tell them
about this kind of thing.

> - you can make a "really nice" skybox in 3DSMAX.
> i would prefer that over a skydome.

It depends a lot on the application.

Skyboxes really stink when you want the eyepoint to move over large
distances at high speed - or if you want things like wind-blown clouds.

Curt's offer of his skydome code comes from FlightGear which *needs*
a dome for the sky.  Obviously as an SSG-Util function, it would be
optional.  If you have something to offer to make good use of 3DSMAX
sky boxes - then I'd be happy to consider it.

> - Welcome back Steve and Happy St Patricks Day!  I hope everyone has
> planted their potatoes in the northern hemisphere.

I always plant my potatoes in the northern hemisphere - it's too far
to walk to get to the southern hemisphere.   :-)

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

Yes, actually I saw Dave's messages about OBJ well after he had
committed the code; I had some other diversions, but I still need an OBJ
loader that does textures, so I will do it.  The only question is
whether I should just dump my version and add textures to Dave's loader,
or continue with mine.

Bill Weiland

Steve Baker wrote:
> 
> Dave McClurg wrote:
> 
> > I commited Wavefront OBJ import/export functions to PLIB/SSG
> > They only handle geometry right now
> > If someone can give me to a texture mapped OBJ model, i'll work on
> > adding the texture support
> 
> Bill Weiland <bil...@ch...> said that he was working on an SSG
> loader that would be ready "probably within the next few weeks"...dunno
> what happened to that.
> 
> Bill - are you listening?
>

Bill Weiland2 wrote:
> 
> Yes, actually I saw Dave's messages about OBJ well after he had
> committed the code; I had some other diversions, but I still need an OBJ
> loader that does textures, so I will do it.  The only question is
> whether I should just dump my version and add textures to Dave's loader,
> or continue with mine.

Yep - it's a hard call.  Make sure you tell this list what you decide
so that Dave knows not to tread on what you are doing.

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

Thread: Re: [Plib-devel] DXF load/save

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