gdalgorithms-list

[algorithms] Polygon reduction & texture

[mandor <ma...@sd...>]

Hi
I'v implemented the polygon reduction algo described by S. Melax in
gdmag (ok, it was easy: he gives the source code :) ). But now, I have
to texture the reduced object, and I was wondering what was the common
approach in this case...?

Thx 

Mandor

[Algorithms] Real-Time Shadows

[Pai-Hung C. <pa...@ac...>]

Hi,

I am palnning to use traditional Shadow Volume technique to generate dynamic
shadows.  Can anyone help me start on how to calculate shadow polygons
(bounding polygons of the shadow volumne) in the world space?  (I use
Direct3D.)  Also, I am wondering if shadow volume is the right choice for
real-time 3D games to generate shadows.  In my case, I am using Quake II
models as my characters, each of which is composed of 500~1000 polygons.
Can someone in-the-know tell me how shadows are typically generated in 3D
RPG games?

BTW, can someone point me to any tutorials detailing how to calculate
object's silhouette and then build shadow volume from it?

Thank you,

Pai-Hung Chen

RE: [algorithms] Polygon reduction & texture

[David N. <ma...@je...>]

> Hi
> I'v implemented the polygon reduction algo described by S. Melax in
> gdmag (ok, it was easy: he gives the source code :) ). But now, I have
> to texture the reduced object, and I was wondering what was the common
> approach in this case...?
>
> Thx
>

In my LOD module you can flag out with a mask as NOT collapsable  vertices
with certain properties, like having different material, border vertices,
smoothing groups, different uvs, etc... This is because my aproach (and
almost anybody's for the sake of api efficiency) is NOT generating new
vertices.

The only real problem is educating artists to make them know how things work
and to use that knowledge to get better quality LOD.

Regards

David Notario

Re: [algorithms] Polygon reduction & texture

[Ales M. <ja...@sl...>]

Stan has a plug-in for 3dsmax that preserves texture coordinates,
material,... Look on his web page for the plug-in, he recently released the
code for it too. It's all there:))

Good man Stan:)

----- Original Message -----
From: mandor <ma...@sd...>
To: Algorithms List <alg...@3d...>
Sent: Tuesday, July 18, 2000 1:09 PM
Subject: [algorithms] Polygon reduction & texture


> Hi
> I'v implemented the polygon reduction algo described by S. Melax in
> gdmag (ok, it was easy: he gives the source code :) ). But now, I have
> to texture the reduced object, and I was wondering what was the common
> approach in this case...?
>
> Thx
>
> Mandor
>
>
> _______________________________________________
> GDAlgorithms-list mailing list
> GDA...@li...
> http://lists.sourceforge.net/mailman/listinfo/gdalgorithms-list

[Algorithms] 3DS woes.

[Leigh M. <lei...@ro...>]

  Sorry if OT but I have spent way too long on this 3ds exporter thing.

  I wrote some code to read a 3ds file and things work for the most part.  I
have the basic models and texture mapping working right but somethings
wacked.  I have a  house.3ds file that is basicly a box and roof but the
roof never lands on top of the house.  If I join the roof and box then it
works ok.  I do know that there is a local matrix in the file but using it
every which way but loose doesn't help.  The NVidia toolkit viewer also
doesn't show the roof right.  Is this a common thing?  I also looked into a
MAX plugin but there doesn't seem to be much docs on this.

  Any help on getting a model out of MAX would be much appreciated and I can
give my semi-broken code out if it helps fix it.

Leigh McRae

Re: [Algorithms] 3DS woes.

[Jonathan B. <jo...@bo...>]

Leigh McRae wrote:

>   Any help on getting a model out of MAX would be much appreciated and I can
> give my semi-broken code out if it helps fix it.

I would not bother with .3ds files.  It's an old format and is 
not useful for much.

What I did was start with the "ascii exporter plugin", the source for which
is in the MAX sdk.  It is incredibly easy to start with this plugin and
modify it to output whatever file format you want.  Or, you could just
parse the ascii output that this plugin provides.

Look in maxsdk/samples/impexp/asciiexp.

   -Jonathan.

Re: [Algorithms] 3DS woes.

[Marco C. <ma...@pr...>]

----- Original Message -----
From: Leigh McRae <lei...@ro...>
To: <gda...@li...>
Sent: Wednesday, July 19, 2000 3:21 PM
Subject: [Algorithms] 3DS woes.


>   Sorry if OT but I have spent way too long on this 3ds exporter thing.
>
>   I wrote some code to read a 3ds file and things work for the most part.
I
> have the basic models and texture mapping working right but somethings
> wacked.  I have a  house.3ds file that is basicly a box and roof but the
> roof never lands on top of the house.
>The NVidia toolkit viewer also doesn't show the roof right.  Is this a
common thing?
>   Any help on getting a model out of MAX would be much appreciated and I
can
> give my semi-broken code out if it helps fix it.
> Leigh McRae

I found similar problems, common with all other viewers...I fixed it
removing history; if you remove history from 3dS MAX and then export the
.3ds model,it should work fine...


Marco Corbetta
ma...@pr...




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