I don’t think a unified lighting model eliminates the possibility of some light map effects. There is evidence for sharp stencil shadows and soft edged penumbra effects in the screen shots and animations. Clearly this requires two different approaches, even if the scene description is a single one and the approaches are seamlessly “unified”.
A projected light map is still a light map…
Originally posted by dorbie:
[b]I don’t think a unified lighting model eliminates the possibility of some light map effects. There is evidence for sharp stencil shadows and soft edged penumbra effects in the screen shots and animations. Clearly this requires two different approaches, even if the scene description is a single one and the approaches are seamlessly “unified”.
A projected light map is still a light map…[/b]
please stop this talking all the time about the highresmeshes for shadowvolumes and the shadowmaps. carmack states he is using simple shadowvolumes with a from him well and accurate described technology. thats all. and i can’t see any of your fancy softshadows nor any shadowmaps on your screenshot. in fact, it looks like a demo from humus with some different leveldata and quite good drawn meshes. and humus only uses simple bumpmapping and simple shadowvolumes, no fancy new_world_order technology, but the stuff that is actually possible on hardware, instead of your fancy dreamings.
you can’t combine shadowmaps and shadowvolumes in a way they look nice. no way…
stop it till its out or official, okay?
is it just me but from what ive seen half the stuff is the same as was shown at the gf3 lanch (when was that over a year ago?) it does feel like theres quite a bit thats being keep back, but then again doom3 will have to come out soon before opengl2.0 comes upon us.
davepermen. I wouldnt see it like that. There are definitively hints on the usage of soft shadows. Look at the background of the scene with the bridge moving.
What? 
I can see them, you’d have to be blind to miss them. There are soft shadows and sharp shadows in some of the animations. That’s a simple fact Dave.
As for the high vs low res meshes, I never said there were different resolution meshes for geometry vs shadow. I pointed out some obvious problems with shadow meshes which differ in resolution from the casting meshes which must cap them so they are therefore very unlikely. As for the bump maps, it’s documented that bumpmaps are being used to reconstruct high res geometric appearance on a low res poly mesh in Doom3. Probably similar to this paper:
http://www.cs.unc.edu/~olano/papers/aps/APSlossy.pdf
We can have any technical discussion we like here without everyone’s approval. This is not a threat to anyone, let us discuss & learn, if you don’t like it then move on but there’s no need to get defensive.
Discussions about high res models vs low res poly meshes help some people to learn that there are potential artifacts with this and lead to discussions about generating bump mapped low res poly models from higher resolution geometry. It’s fun, it’s educational and it is on topic. There’s no need to try and censor this discussion.
Look at the soft shadows on the walls in the video sequence of the demon walking down the hallway. There appear to be several that are are independently modulated (they appear to flicker independently) and they are combined with sharp stencil shadows cast from other sources. It’s obvious that some kind to light texture modulation is going on, whether it’s depth texture or light map I don’t know but it IS being rendered like this.
Now, this may be something as simple as a projective texture on each light, but let’s not pretend they aren’t there simply because Carmack has written a consistent light model.
I am with Davepermen on this one. There are no soft shadows casted from objects. Sure the spotlights softly dies down, but the shadow casted from objects is definitely only hard.
The bathroom scene demontrates this very well.
There are soft shadows, perhaps not cast from objects (it’s difficult to tell), but they exist. They are light modulating textures, i.e. light maps. They appear to fixed and they overlap and are independently modulated to emphasize multiple light sources. I suspect they are projected. They appear to correctly modulate on the dynamic character.
Look here:
http://www.doom-3.net/E3/36.jpg
Look at the walls.
There are also some interesting lights on the gantry in the background of this shot, I’m not suggesting these little eye candy lights are full light sources and light maps but it does indicate that the creation of light sources in this engine is more pragmatic and flexible than is being assumed.
BTW it would make some sense to cook occulting objects near lights into a texture and project it for objects in the beam tree beyond the near occulter. It would give a soft edge effect and significantly reduce shadow volume stencil pass depth complexity. This would still be a unified model. It’s simply another optimization.
Reguardless of whether this is or isn’t in the engine, it’s a valid general observation.
Originally posted by dorbie:
I don’t think a unified lighting model eliminates the possibility of some light map effects.
Does this eliminate it enough for you?
“The big things from the graphics side are the complete unification of lighting, shadowing, and bump mapping across all visual elements. In previous games, we had to use a variety of techniques to light the combinations of static and dynamic lights versus static and dynamic surfaces, which tended to give games a characteristic separation between active elements, like monsters, and the rest of the world. There are lots of effects with light and shadow that people have always wanted to see in games that just work naturally now, with no special hacks.”
Notice how he keeps reiterating “unified”, “complete”, and talks about how he used to have to mike different techniques together but no longer has to. I dont think the explanation could be any clearer if John Carmack knocked on your front door, sat down in your living room, and explained it 100 times.
There is evidence for sharp stencil shadows and soft edged penumbra effects in the screen shots and animations.
Huh??? What the $#!*@??? Could you please, please, please, please, PLEASE show me where this “evidence” is. I dont see anything like that in any of the pictures I looked at. I do see soft edges in the distance attenuation and diffuse self-shadowing, but no soft shadows.
That’s a simple fact Dave.
Well, maybe a fact in your corner of the galaxy, but not over here on planet earth. File that under “O” for “opinion”, or maybe “I” for “interpretation” 
it does look like the soft shadows in the pictures are coming from projected textures the problem though is its very hard to make the work when the light is very close to the object (from my experimentation a while ago, at the moment i cant remember why that is) but they work perfectly for stationary lights/objects but personally having exceptions like this doesnt feel like a ‘unified shading system thingee’
i do agree both with dorbie (btw thanks for the www.doom-3.net link, until now i could only find a few screenshots) + the others (ie dorbie vs the world)
true the lightmap doesnt have to be precalculated (ive got a nice demo if anyone cares to look), (its a little bit faster if it is but its not really that much slower when its on the fly) but personally doing various sorts of lighting depending on what the light or object is is not IMHO unified lighting
another point looking at the screenshots it does look like stencil shadows but theyre all black which personally looks crap.
[This message has been edited by zed (edited 05-24-2002).]
Lord Kronos,
See my post above. In the video these light maps flicker with different intensities. Here’s the link again:
http://www.doom-3.net/E3/36.jpg
I just don’t get it, why are people getting their panties in a twist over this? It’s plain as day, and even if it wasn’t it’d just be a discussion over some interesting technology.
Why the abuse? You’d think I’d killed your dog or something.
A light map doesn’t have to be precalculated and is not incompatible with a unified consistent lighting model.
[This message has been edited by dorbie (edited 05-24-2002).]
Zed, it would be unified if 1) they are just projected luminaire textures, or 2) they are auto generated from near occulters. There are other options but I won’t mention them for fear of upsetting the unified purists reading.
Originally posted by dorbie:
Lord Kronos,
Here’s the link again:
http://www.doom-3.net/E3/36.jpg
You posted that link after I already started typing my response, so I didnt see it. Although the compression artifacts on that image are horrible, my best guess would be that it is encoded into the attenuation map (like the way I do spotlights and disco lights in my tutorials). This is completely different from a shadow.
I just don’t get it, why are people getting their panties in a twist over this?
It’s plain as day…Why the abuse?
Whose getting abusive? I dont see anything like that. Perhaps you’re just being over-sensitive?
In support of dorbie, I definitely see soft shadows in the mpeg. You can see that there’s a marked distinction between the shadow volumes of the characters and some of the animated scenery. Such as the scene with the rotating air vent fan with a light behind it - they seem to be projecting the fan as a texture onto all geometry in its frustum.
Ron, “over here on planet Earth” we call that style of post abusive.
You should try and download the E3 video, it has the same scene in the video at about 5fps, crappy resolution but it shows you the independent modulation of the multiple maps.
It could be built into the attenuation map as you say, and infact even if it were a shadow it probably should be built in there too. The key observation is that it could easily be generated from scene geometry and doing this could significantly improve performance for static lights, and it would still be “unified”.
I think this paper may be related to what is being done here:
Fast Soft Shadows, Michael Herf and Paul Heckbert, Technical Sketch, New Orleans, Aug. 1996, SIGGRAPH '96 Visual Proceedings, p. 145.
In anycase we should be able to discuss this without getting flamed by people who are way too adamant about their speculation.
Yeah, let’s keep is civil.
John Carmack is doing some pretty cool stuff in Doom3. It’s interesting to speculate on exactly what he’s doing, but until you can play the game yourself, it’ll have to remain speculation.
Unless, of course, Shag can get him to post on OpenGL.org.
Cass
Originally posted by dorbie:
Ron, “over here on planet Earth” we call that style of post abusive.
Not me. I was just making a cute little joke. You were going around trying to pass off your opinion or interpretation as “a simple fact”. I was reminding you the difference between fact and opinion/interpretation.
And by the way…“I can see them, you’d have to be blind to miss them” could just as well be considered abusive by the same lines.
You should try and download the E3 video
Do you have a link? Because the only video I have been able to find is that old Mac expo one from last year (or whatever).
In anycase we should be able to discuss this without getting flamed…
I dont see any flaming. I think you are just being over sensitive. Was I getting a slight bit irritated? Possibly, because the gist of this thread has been:
It looks like lightmaps
John said there are no lightmaps
I think they could be lightmaps
John said there are no lightmaps
You could still mix <whatever> and lightmaps
John said there are no lightmaps
Just because everything’s unified doesnt mean they arent lightmaps
John said there are no lightmaps.
[This message has been edited by LordKronos (edited 05-24-2002).]
[This message has been edited by LordKronos (edited 05-24-2002).]
Originally posted by cass:
Unless, of course, Shag can get him to post on OpenGL.org.
Yeah, Shag. And dont forget to get him to post a link to the binary for us
Take a copy of the image in question, and copy into PSP or someother paint program.
Enlarge the section around the feet where BOTH types of shadow are present. The shadow generated from the monster is totally different to the other shadow. This simply means one of two things:
The second technique could still easily fall within a unified lighting approach: If static shadow geometry is precalculated and stored within the BSP (assuming there is a BSP) as ‘normal’ polys, then it wouldn’t be too hard to create soft shadows using some jittering method.
Think about it - a simple case would be a pillar in a square room - six quads would make the shadow volume. redrawing this another 6 times (3 either side) creates a total of 42 polys. Not too bad really. However, a complex model would contain several hundred polys minimum.
I can’t be arsed to think exactly how it would be done, but geometry wise, it should be quite possible.
OR … it’s a lightmap
Regards
i take it by lightmaps everyone means projected textures containing the lighting info (well thats the sense i used it in)
