Per vertex or per pixel lighting?

Per vertex or per pixel lighting?

Post by Jedediah Smit » Sat, 13 Jan 2001 11:29:15



I've been led to believe that in typical realtime 3D engines (i.e.
games), all lighting is calculated per-vertex and then interpolated
across polys with gourad shading. If this is so, how do you shine a
spotlight on the middle of a large wall made of a single poly? Would the
engine divide the wall into lots of smaller polys?

Thanx

--

http://www.silencegreys.com/extension/

 
 
 

Per vertex or per pixel lighting?

Post by ZZ » Sat, 13 Jan 2001 15:12:38


either that or use a lightmap or use one of the various per pixel techniques

--
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zed zeek - big bollucked king of the world , messiah , and all round nice guy.
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> I've been led to believe that in typical realtime 3D engines (i.e.
> games), all lighting is calculated per-vertex and then interpolated
> across polys with gourad shading. If this is so, how do you shine a
> spotlight on the middle of a large wall made of a single poly? Would the
> engine divide the wall into lots of smaller polys?

> Thanx

> --

> http://www.silencegreys.com/extension/


 
 
 

Per vertex or per pixel lighting?

Post by Florent CUR » Sat, 13 Jan 2001 19:48:18


Quote:> I've been led to believe that in typical realtime 3D engines (i.e.
> games), all lighting is calculated per-vertex and then interpolated
> across polys with gourad shading. If this is so, how do you shine a
> spotlight on the middle of a large wall made of a single poly? Would the
> engine divide the wall into lots of smaller polys?

search for lightmapping
 
 
 

Per vertex or per pixel lighting?

Post by Jedediah Smit » Sat, 13 Jan 2001 20:39:26


How would a typical modern game engine handle a dynamic light source
like a glowing projectile? Surely realtime lightmaps would be too slow?
What per pixel techniques are supported by hardware 3D accelerators?


> either that or use a lightmap or use one of the various per pixel techniques

> --
> lets hear it 4 billy bollux and his AMAZING bouuuncing balls
> zed zeek - big bollucked king of the world , messiah , and all round nice guy.
> GET IT HERE http://members.xoom.com/myBollux  FREE BOLLUX



> > I've been led to believe that in typical realtime 3D engines (i.e.
> > games), all lighting is calculated per-vertex and then interpolated
> > across polys with gourad shading. If this is so, how do you shine a
> > spotlight on the middle of a large wall made of a single poly? Would the
> > engine divide the wall into lots of smaller polys?

> > Thanx

> > --

> > http://www.silencegreys.com/extension/

--

http://www.silencegreys.com/extension/
 
 
 

Per vertex or per pixel lighting?

Post by erik robso » Sun, 14 Jan 2001 03:47:19


On Fri, 12 Jan 2001 11:39:26 GMT, Jedediah Smith


>How would a typical modern game engine handle a dynamic light source
>like a glowing projectile? Surely realtime lightmaps would be too slow?
>What per pixel techniques are supported by hardware 3D accelerators?

No, it's not too slow to rebuild select lightmaps in real-time.
However, I'm guessing that the "next generation" of engines will do
lighting much more dynamically.  (See Carmack's notes on the upcoming
Doom 3 engine.)
 
 
 

Per vertex or per pixel lighting?

Post by ZZ » Sun, 14 Jan 2001 08:29:40


-no its not that slow remember lightmaps are typically very low resolution eg
16x16 (check out quake2/3) notice they dont look that great and they dont cast
shadows but hey if ppl dont really notice someit u can get away with it.

-nvidia register combiners

--
lets hear it 4 billy bollux and his AMAZING bouuuncing balls
zed zeek - big bollucked king of the world , messiah , and all round nice guy.
GET IT HERE http://members.xoom.com/myBollux  FREE BOLLUX


Quote:

> How would a typical modern game engine handle a dynamic light source
> like a glowing projectile? Surely realtime lightmaps would be too slow?
> What per pixel techniques are supported by hardware 3D accelerators?

 
 
 

Per vertex or per pixel lighting?

Post by Paul Shirle » Sun, 14 Jan 2001 07:01:17




>On Fri, 12 Jan 2001 11:39:26 GMT, Jedediah Smith

>>How would a typical modern game engine handle a dynamic light source
>>like a glowing projectile? Surely realtime lightmaps would be too slow?
>>What per pixel techniques are supported by hardware 3D accelerators?

>No, it's not too slow to rebuild select lightmaps in real-time.
>However, I'm guessing that the "next generation" of engines will do
>lighting much more dynamically.  (See Carmack's notes on the upcoming
>Doom 3 engine.)

Unreal already performs real-time lightmap generation,most of the trick
lighting effects do it. I'm not going to pull the source out to check
but I think the projectiles also do it (with a lot of shortcuts).

It has a noticeable impact on speed but was fast enough to use 2 years
ago.

--
Paul Shirley

 
 
 

Per vertex or per pixel lighting?

Post by Jim » Thu, 18 Jan 2001 06:14:05


On Fri, 12 Jan 2001 22:01:17 +0000, Paul Shirley


>Unreal already performs real-time lightmap generation,most of the trick
>lighting effects do it. I'm not going to pull the source out to check
>but I think the projectiles also do it (with a lot of shortcuts).

>It has a noticeable impact on speed but was fast enough to use 2 years
>ago.

Didn't Descent 1 have a "shining projectile" that lit the walls...
That must have been 1995ish.  :-)

Jimbo

 
 
 

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