Unreal 3.0 and Dynamic Radiosity Lighting

[MfA]

Elegance

 

[Farid]

Is there a PC-version coming soon of this game if you happan to know?

Yes, Starbreeze Studios is working on the PC version, that's confirmed.

They both do. It's just veeerrrrry subtle (especially DXIW), and without specular maps, even more so.

The worse is that they actually have specular maps... The engine is just dealing with them strangely.

 

[Luminescent]

According to Carmack and most experts here, Doom 3 was the first widespread engine to provide support for a hardware accelerated globalized lighting model

I wouldnt call that a globalized lighting model, it is a unified lighting model.

As for UE-3 it seems it is just the good old mix of offline radiosity and online local lighting models (soft shadows not withstanding). Or in other words the return to a non unified lighting model.

Good point. I guess unified is the proper term.

In reference to Doom 3:

And as mentioned before, there are objects that don't shadow at all.

In the flashlight thread it was mentioned that stencil shadows were intentionally omitted for objects such as grates, composed of very simple quads, because shadow detail did not correspond well to normal map detail. Is this the case you are referring to?

 

[Scali]

In the flashlight thread it was mentioned that stencil shadows were intentionally omitted for objects such as grates, composed of very simple quads, because shadow detail did not correspond well to normal map detail. Is this the case you are referring to?

The grates are one case. Characters without self-shadowing are another. In this case they were not removed because the shadows would be terribly wrong, but rather because they would not make the game look better (sometimes even worse), so for performance-reasons it's best to disable them. And that is what breaks the unified system. Special cases were introduced.

So Doom3 is just as much a hackjob as all other games mentioned in this thread. Apparently Carmack did a better job of selling it than the other developers.

 

[anaqer]

Special cases were introduced.

Welcome to the world of 3D graphics, home of cheats and special cases. 8)

 

[Bambers]

Thief 3 has the shadowing, but I don't think it has the bump mapping. The demo I downloaded had a completely different look and feel, to me. Haven't yet played Deus Ex 2.

both thief3 and DX:IW use bumpmapping although not exclusively on every single object. Floors, walls etc are usually bumpmapped however. Not sure about DX:IW but thief 3 certainly uses bumpmapping on the characters as well.

I tend to prefer the lighting in t3, no unrealistic 100% pitch black corners (I assume its using lightmaps or something in addition to the other lighting) unlike doom3 which has innumerable situations of places that clearly should not be pitch black yet are. Plenty of the office areas have shadows behind the desks that you can't see anything in unless you use the flashlight. :?

 

[Scali]

Special cases were introduced.

Welcome to the world of 3D graphics, home of cheats and special cases. 8)

Duh

 

[Goragoth]

The grates are one case. Characters without self-shadowing are another. In this case they were not removed because the shadows would be terribly wrong, but rather because they would not make the game look better (sometimes even worse), so for performance-reasons it's best to disable them. And that is what breaks the unified system. Special cases were introduced.

The lighting model is still unified in the sense that there is just one lighting model for everything. Some things just don't use it. For example if you have one way of doing shadows and some objects have them and some don't doesn't mean that you suddenly have two types of shadows, they are just on or off. Not everything is treated the same but that doesn't mean you can't call it a unified lighting model.

I think the whole ULM thing is a load bs anyway, it doesn't mean much in itself, heck any game that uses just vertex lighting (no lightmaps) has a ULM. Big deal. Should have called a "completely realtime lighting model" or something because that's really the key, everything is done in realtime with no offline processing step in the map creation stage.

 

[KimB]

I think the key is more that Doom 3 was able to look better than pretty much any other game outhere while at the same time using a unified lighting model.

Pretty much any other game has needed to preprocess a lot of graphics stuff to get it to look good. Doom 3 doesn't. That's where the magic lies.

 

[Scali]

The lighting model is still unified in the sense that there is just one lighting model for everything. Some things just don't use it. For example if you have one way of doing shadows and some objects have them and some don't doesn't mean that you suddenly have two types of shadows, they are just on or off. Not everything is treated the same but that doesn't mean you can't call it a unified lighting model.

What about the projected light and shadows? They are clearly a different lighting model.
The only thing that is unified is the surface shader. There is only one shader for interaction with light and surface. The parameters of the shader determine the final look. But I see that as a disadvantage rather than an advantage.

 

[davepermen]

nope, the lightmap is just another property of each and every light (required to have something else than pointlights, a.k.a. spotlights). it's like the diffuse colour on a material, the projected lightmaps are a direction dependent colour map bindable onto a light. it can fake coloured lights from glass, or shadows from some grids, or what ever.. or disco-lights, beacons, etc.. it's all the same.

 

[Scali]

nope, the lightmap is just another property of each and every light (required to have something else than pointlights, a.k.a. spotlights). it's like the diffuse colour on a material, the projected lightmaps are a direction dependent colour map bindable onto a light. it can fake coloured lights from glass, or shadows from some grids, or what ever.. or disco-lights, beacons, etc.. it's all the same.

Nonsense, since most lights have no lightmap at all: special cases.
Also, I don't think that eg the fans actually have a regular lightsource at all. Only the projected light/shadow are added to the scene, no stencil shadows are cast, and no light calculations based on distance or angle.

It's simple: there are special cases. If you still think that Doom3 has a unified model, then what is the difference with eg UE3.0? It also has a unified model, with some special cases.
Doom3 is nothing special, either they are all unified, or none of them are.

 

[davepermen]

nope, scali, they are not. you're spitting out nonsence. each and every light can simply get such a light. of course the engine is allowed to optimise for the fact most lights don't use that feature. still, it's just a supported feature, and every light is capable of using it.

it is unified as you can have at every position in the game all features at once. there is no "oh, here, shadows are impossible" or "oh, no, this light can't have a directional colour map (the projected shadows for example)".

if this is not possible, it's not unified. in doom3, everything is based on the same. there are lights that don't require all features, thus, they don't have them. it would be a waste else. but it's an artists choise. they HAVE the choise. just because the artist disables some stuff doesn't mean it's not unified.

 

[Diplo]

I think you can sum this up by saying the Doom 3 engine is capable of presenting a unified lighting model but the Doom 3 game does not do so.

 

[Scali]

I think you can sum this up by saying the Doom 3 engine is capable of presenting a unified lighting model but the Doom 3 game does not do so.

Which is a useless statement. Every engine is capable of a unified lighting model, as said before. Even vertex light + lightmaps on everything is a unified model. You can always find a subset of features and techniques that work in all cases. Which would be 'unified'.

 

[Scali]

nope, scali, they are not. you're spitting out nonsence.

For your information, as said before, the grates cannot cast shadows with the 'unified' stencilshadow method, they NEED the projected lightmaps.
So who is spitting out nonsense? I know, the rude and arrogant guy who can't even spell 'nonsense'!

 

[Diplo]

Which is a useless statement. Every engine is capable of a unified lighting model, as said before.

True if you are being literal, but in the context of this discussion we were defining "unified" in the manner which Carmack meant it, not some general sense.

 

[Scali]

True if you are being literal, but in the context of this discussion we were defining "unified" in the manner which Carmack meant it, not some general sense.

That is another useless statement. If Carmack defines 'unified' by Doom3 itself, then obviously by his definition of 'unified', Doom3 is unified.

I think the discussion is more about Carmack's definition not being a correct one, but more like marketing buzzword-stuff.
After all, his engine is not significantly different from other engines that support shaders, projected lightmaps and dynamic shadows.

 

[Sigma]

For your information, as said before, the grates cannot cast shadows with the 'unified' stencilshadow method, they NEED the projected lightmaps.

Jesus. I don't get it. In the flashlight thread it was explained why the grates didn't cast shadows. The grates are simulated geometry with a texture with an alpha channel. Of course that any geometry based shadow solution can't project shadows of geometric detail faked in a texture. Build the grates out of triangles and it will cast a shadow...
While you're at it, complain that the grates seen from the side don't have any depth. That they have this weird look, like they are lying in a plane...

And stop making confusion about shadows and the light frustum simulated with projected spotlight textures... Shadows are volumes within the light frustum where the given light doesn't reach.

It is unified because moving and non moving objects are treated equal and every light created "just works" (including shadows. Scali you read: geometric based shadows).

So who is spitting out nonsense? I know, the rude and arrogant guy who can't even spell 'nonsense'!

"So"?! :? You assume you are right...
davepermen is right, even the 'nonsense' part.

 

[KimB]

Which is a useless statement. Every engine is capable of a unified lighting model, as said before. Even vertex light + lightmaps on everything is a unified model. You can always find a subset of features and techniques that work in all cases. Which would be 'unified'.

No, not really. Most engines have a fundamentally different lighting model for world geometry than for moving objects. This is the key difference with Doom 3. There is no difference between world geometry and moving objects. This allows for much greater potential in animation of the world, as as far as the rendering is concerned, there will be little to no performance hit (or visual difference) from animating objects that usually aren't animated in the game.

By getting rid of preprocessing, Doom 3 opens the door for much more motion in game worlds.