View Full Version : Carmack talks Doom 3
Doomtrooper
09-Feb-2002, 09:27
Small interview on Gamespot, pretty interesting stuff.
http://gamespot.com/gamespot/filters/products/media/0,11100,469881,00.html
Yep, also pretty stale. :smile:
LeStoffer
09-Feb-2002, 10:42
Damn, I thought that this was a whole new interview...
Anyway, yes, it was very interesting and I think the Doom III-engine will finally show us what hardware T&L is all about. I'm not really looking that much forward to more polygons - it's nice and all but the whole lightning part of Doom III is going to be awesome. This is were (T&)L will shine IMO. Die lightmaps - die!!!
REgards, LeStoffer
Ozymandis
09-Feb-2002, 10:45
Does the new engine use lightmaps at all? Just curious.
bystander
09-Feb-2002, 10:49
Completely unrelated to the main thread. But it's awkward, that phpBB, sees a comma as the end of the url.
http://gamespot.com/gamespot/filters/products/media/0,11100,469881,00.html
<font size=-1>[ This Message was edited by: bystander on 2002-02-09 11:54 ]</font>
On 2002-02-09 11:42, LeStoffer wrote:
Damn, I thought that this was a whole new interview...
Anyway, yes, it was very interesting and I think the Doom III-engine will finally show us what hardware T&L is all about. I'm not really looking that much forward to more polygons - it's nice and all but the whole lightning part of Doom III is going to be awesome. This is were (T&)L will shine IMO. Die lightmaps - die!!!
REgards, LeStoffer
Actually, I don't think it'll use "L" in T&L at all. It's done with DOT3.
LeStoffer
09-Feb-2002, 12:31
On 2002-02-09 12:11, Humus wrote:
Actually, I don't think it'll use "L" in T&L at all. It's done with DOT3.
Humus: Okay, as you can tell I don't know much about how light is "projected" onto a given triangle/texture, but I thought that you either had to use a lightmap (mapped upon a texture) or a lightsource (CPU/software or Hardware L) on a mesh of triangles? Wouldn't DOT3 have to use one of these?
Hmmm, I guess I have this [odd] understanding from 3Dmax.
Regards, LeStoffer
On 2002-02-09 13:31, LeStoffer wrote:
On 2002-02-09 12:11, Humus wrote:
Actually, I don't think it'll use "L" in T&L at all. It's done with DOT3.
Humus: Okay, as you can tell I don't know much about how light is "projected" onto a given triangle/texture, but I thought that you either had to use a lightmap (mapped upon a texture) or a lightsource (CPU/software or Hardware L) on a mesh of triangles? Wouldn't DOT3 have to use one of these?
Hmmm, I guess I have this [odd] understanding from 3Dmax.
Regards, LeStoffer
That would be vertex lighting (using gpu L), j.c does per pixel lighting with dot3 bumpmapping although i'm not 100% sure.
DemoCoder
09-Feb-2002, 13:10
Even with DOT3 you need the vertex shader (e.g. T&L stage) to perform per vertex lighting calculations, for example, if you are using local lights or if you are doing anything more complicated than bog standard diffuse and specular per-pixel calculations.
But Carmack has said in the past that Doom3 doesn't use a lot of polygons. It uses imposters.
Per-vertex calculations are very useful when setting up the per-pixel stage.
<font size=-1>[ This Message was edited by: DemoCoder on 2002-02-09 14:10 ]</font>
That would be vertex lighting (using gpu L), j.c does per pixel lighting with dot3 bumpmapping although i'm not 100% sure.
Yes, they generate normal maps from high-poly models but use "low-poly" models in the game. The per-pixel dot3 lighting based on these normal maps makes sure the models still look very impressive even with "few" polygons. Of course the silhouettes won't look perfectly smooth.
LeStoffer
09-Feb-2002, 13:30
On 2002-02-09 14:10, DemoCoder wrote:
Even with DOT3 you need the vertex shader (e.g. T&L stage) to perform per vertex lighting calculations, for example, if you are using local lights or if you are doing anything more complicated than bog standard diffuse and specular per-pixel calculations.
This was what I meant. :oops:
But in what cases do you not need to use vertex lighting calculations if you discard the use of lightmaps [with DOT3]? I ask because you always will need some kind af lightsource unless a texture is to be absolutely black. Right? Wrong?
Thank for any clarification. :oops:
Regards, LeStoffer
JF_Aidan_Pryde
09-Feb-2002, 13:47
Imposters?
Please elaborate :smile:
Well, there are loads of ways of doing it. You can put the tangent space normal into color and do a dot 3 with the normal map. Another way is to use some texgen and a texture matrix to rotate a 3d vector field texture into the tangent space and DOT with the normal map, which is something I've done in the volumetric demo you can find here (http://hem.passagen.se/emiper/3d.html). This way you can put attuenation into it without any additional math. You can also replace the 3d texture with a normalizing cubemap and do the attenuation with a 2d and a 1d luminance texture.
Anyway, when someone says "T&L" the L usually mean traditional vertex lighting, at least that was what it meant when the original GF arrived. But you can maybe include texgen/vertex shaders etc. into the definition of L too.
On 2002-02-09 14:30, LeStoffer wrote:
But in what cases do you not need to use vertex lighting calculations if you discard the use of lightmaps [with DOT3]? I ask because you always will need some kind af lightsource unless a texture is to be absolutely black. Right? Wrong?
Thank for any clarification. :oops:
Regards, LeStoffer
Well, you don't need any lights in the traditional glEnable(GL_LIGHT0) sense, but you'll of course need to represent them in your world in way or the other, possibly only storing the position and intensity. What DOT3 does is that make a dot product between the surface normal (stored per pixel in the normal map texture) and the light vector normalized. A dot product between two vectors of size 1 gives you the cosine of the angle between the vectors, which is exactly the factor you want for diffuse lighting. You then modulate this with the base texture. With traditional vertex lighting you'd only dot this at each vertex and interpolate the light color to modulate with the base textures, which give worse quality than using lightmaps. The problem with lightmaps are that they are many and can thus only be small and thus can't give you a expecially good lighting. The other problem is that they are static. Both these can be solved with dot3, but the problem with dot3 bumpmapping is that you don't get any shadows as you could get with lightmaps, thus you need to use shadow volumes or shadow mapping to shadows back.
Dave B(TotalVR)
09-Feb-2002, 15:06
Jesus, on offence to the man he is a brilliant programmer, but he sounds like such a nerdy little teenager!
Doom 3 sounds like its going to be damn good - 5 years after its release coz no cards will run it properly:P
Dave
Doomtrooper
09-Feb-2002, 19:37
I was thinking the same thing about the 'nerd' part :smile:
Yet he has made some nice engines, as for Quake 3 gameplay..Bleh !
Brimstone
10-Feb-2002, 07:14
Am I the only person looking forward to New World Order? The game has all the fancy 3d buzzwords in it (Per Pixel Lighting, Bump Mapping, and so on) and the playable demo is coming out soon.
The NWO team hasn't released a game, so I guess thats a legitimate reason not to get to excited about the game. But the tech demo showing off the levels look so damn good, I wish more people knew about the game.
Doom 3 will be an incredible experience though. The Mac World video looked so creepy with the lighting effects, I love it.
Richard999
10-Feb-2002, 07:20
I think it's safe to say that I can hardly wait for some form of Doom3 news. Granted, I'd prefer the game out tomorrow, but I'll settle for some nice updates on when the game is supposed to be ready.
nooneyouknow
10-Feb-2002, 07:45
NWO is going to look fantastic... They have a press release talking about their ATI support which means Truform, PS 1.4, etc..
Wonder how the gamplay will be.. No doubt it will look great...
Brimstone
10-Feb-2002, 08:33
Wow...it's great to hear that another person thinks NWO has potential. The game doesn't have any problems when it comes to graphics. Doom 3 and Unreal 2 deserve the attention they get, but it would be nice to see NWO get a litte more mainstream coverage besides just Voodoo Extreme.
Can someone post some links to NWO info?
Brimstone
10-Feb-2002, 09:31
Sure...
http://www.p3int.com/downloads_NWO.asp
Both tech demos are worth the download. You'll find more information on the site. I post on the NWO forum over there.
Enjoy.
While doing some research, I ran across a technical presentation by NVIDIA's Mark Kilgard - CEDEC 2001 -- Robust Stencil Shadow Volumes. It provides some insight to shadow techniques Carmack is developing for the new Doom.
http://developer.nvidia.com/docs/IO/1451/ATT/StencilShadows_CEDEC_E.pdf
Entropy
10-Feb-2002, 10:55
Doomtrooper, what most casual gamers don't see is that Quake3 is a sport, not a game. It is all about skill and skill development, and the fun a player gets from it (or not) is the same kind of fun you get from doing any other kind of sport. Which isn't quite what most other games aim for. DOOM3 will, in its first incarnation at least, have a completely different focus, and will probably appeal more to someone looking for a nice game type experience. It may not ever have the same foothold among the online gamers, because due to the way it was initially said to be programmed, it would be more open to cheating.
Then again, that never stopped CounterStrike from being popular.
Entropy
Brimstone
10-Feb-2002, 11:08
While doing some research, I ran across a technical presentation by NVIDIA's Mark Kilgard - CEDEC 2001 -- Robust Stencil Shadow Volumes. It provides some insight to shadow techniques Carmack is developing for the new Doom.
I like the statement near the end, it doesn't beat around the bush.
"Carmacks optimizations in these area's will make the Doom engine awesome"
John Carmack has a very impressive mind and that's probably an understatment.
The NWO developers dont seem to be very good at PR, you'd at least expect a nice website with a forum (I know they have the forum ... but damn it all looks pretty drab) with regular posts of new screenshots etc etc.
Brimstone
10-Feb-2002, 11:42
The NWO developers dont seem to be very good at PR, you'd at least expect a nice website with a forum (I know they have the forum ... but damn it all looks pretty drab) with regular posts of new screenshots etc etc.
I care about how the game plays, sounds, and looks more than the quality of the website. The demo is the most important thing for me. The website seem fine to me, nothing spectacular just functional. Flash websites with fancy effects aren't important to me. I want a game that is awesome, not an awesome website.
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