nV News Forums

 
 

nV News Forums (http://www.nvnews.net/vbulletin/index.php)
-   Gaming Central (http://www.nvnews.net/vbulletin/forumdisplay.php?f=12)
-   -   Doom 3 pre-rendered "dynamic shadows" ? (http://www.nvnews.net/vbulletin/showthread.php?t=33817)

Sazar 08-03-04 01:39 PM

Doom 3 pre-rendered "dynamic shadows" ?
 
2 Attachment(s)
just a little investigation into doom 3's shadow rendering technique...

I was initially under the impression each shadow cast was completely independent and rendered according to the light source and rather cool...

it would appear that instead every single shadow in the game is a pre-stenciled entity that just becomes darker (or lighter or does not appear) depending on the light-source angle and the intensity of the light-source...

the dynamic part is it moves and becomes lighter and darker... it is not dynamic in so much as it varies per curvatures or gradient or distance or any other such thing... so often you will see a shadow being rendered in plain air...

granted that Mars has a dusty environment but its a bit strange still :cool:

anyone care to shed any light on doom 3's shadow technique...

shots taken @ 12x10/high quality/cropped for this post

-edit- updates as later in this thread...

it would appear these situations are not so widespread and limited instead to particular situations... other than these instances the shadows indeed appear to be dynamic for the most part...

CaptNKILL 08-03-04 01:55 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
I think i know what youre talking about but I dont think its wrong, even though it looks that way. If you hold a flashlight and shine it, the lightsource comes from your hand, so the shape of the shadows you will see will be almost identical to the object casting them. Is that what you are talking about? The way the shadows seem to just be stripes, rather than going up the walls at angles?

Edit: Yeah, as lame as it sounds I just tried it :p
I just got a flashlight, and a pencil, held the pencil on end on my desk, and pointed the light from my shoulder at the pencil, toward a wall... the shadow is a straight line. Only if i move my head to the side does is it clear that it bends over everything.

EDIT2: And the reason things appear to not change for distance is because again, the light is coming from you. What is far from the light, is far from you, so it appears smaller. One thread here shows an imp throwing a fire ball, the light coming from the flame in his hand creates a gigantic shadow of his hand across the entire room.

I think you just happened to notice this because youre walking around with a flashlight... plus, the screens you took are in a bit of an odd scene... but they are right, dont worry :)

Sazar 08-03-04 02:05 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
-edited so as not to constitute a conspiracy theory-

|JuiceZ| 08-03-04 02:08 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Quote:

Originally Posted by Sazar
shadows cast off the railings as you can see from my small caps show absolutely no variation depending on the objects behind them... they are just THERE...

blah, didn't notice that until now, o well.

Thx for the doc link btw. ;)

Sazar 08-03-04 02:09 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
-edited so as not to constitute a conspiracy theory-

Clay 08-03-04 02:14 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Interesting Saz, thanks for the info. :) I'd sort of noticed this but didn't pay much attention to it (too busy recording videos lately) :D

CaptNKILL 08-03-04 02:35 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Bah, thats sort of disapointing. I dont understand most of what Carmack says in that text file... not surprising really :p

I guess we havent quite made it to real lighting and shadowing, its still just a simulation... still looks good, but, theres obviously problems with it.

BTW, how the hell does this work in multiplayer? Is there no flashlight? And if thats the case, then this wierd "projected floating shadow" crap is probably just done when the flashlight is used.

Still not sure why he didnt go with real dynamic shadows though. Anyone that can read "carmack-ese" know what he says is the problem? I read something about going behind a projected shadow would cause the screen to be black or something... if thats it, then youd think there would have been an easier way than creating floating shadows :|

Ninjaman09 08-03-04 02:41 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Interesting, but completely wrong. I'm not sure what you meant by "pre-rendered shadows", but I'm assuming you mean light maps, though there was nothing in the text file you linked to suggest that. In fact, I'd like for you to point out the lines you think support your argument. The lights are all dynamic, and every shadow in the game is cast dynamically as well. This has been stated repeatedly by Carmack, and is extremely evident in the game, especially when a different character than yourself has a flashlight (like a sentry bot or the service platform you control later on).

God damn it, would you people stop trying to find faults with the game and just let yourselves enjoy it?!

Clay 08-03-04 02:43 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Quote:

Originally Posted by Ninjaman09
Interesting, but completely wrong. I'm not sure what you meant by "pre-rendered shadows", but I'm assuming you mean light maps, though there was nothing in the text file you linked to suggest that. In fact, I'd like for you to point out the lines you think support your argument. The lights are all dynamic, and every shadow in the game is cast dynamically as well. This has been stated repeatedly by Carmack, and is extremely evident in the game, especially when a different character than yourself has a flashlight (like a sentry bot or the service platform you control later on).

God damn it, would you people stop trying to find faults with the game and just let yourselves enjoy it?!

Mmm, even more interesting. Based on Saz's rebuttal I may have to investigate this for myself tonight. ;)

Intel17 08-03-04 03:03 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
Who cares? Teh game r0x0rz!!

ClosetFanBoy 08-03-04 03:04 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
hmmm. my flashlight doesnt cast a shadow nor can i see my shadow (your supposed to see the marines shadow yes?) i'm playing on high quality. am i missing something here?

Nutty 08-03-04 03:05 PM

Re: Doom 3 pre-rendered "dynamic shadows" ?
 
I dunno what those screenshots are meant to prove ?

If you're talking about the boxes shadow going the other way, thats because theres a light on the other side of the room casting that. If you look around the edge of the box, you can see the shadow the flashlight is casting, but its mostly obscured by the box.

The 2nd image looks fine as well. The shadow is a projection, so it will look straight regardless of the surface it's casting across.

I cant see anything wrong with the images, what's the problem ?


All times are GMT -5. The time now is 03:14 PM.

Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 1998 - 2014, nV News.