Go Back   nV News Forums > Software Forums > Gaming Central

Newegg Daily Deals

Reply
 
Thread Tools
Old 08-03-04, 03:11 PM   #13
UDawg
Retired spammer
 
Join Date: Nov 2002
Posts: 1,799
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

LIES! ALL LIES! Saz is just trying to take our joy away.
UDawg is offline   Reply With Quote
Old 08-03-04, 03:13 PM   #14
Zeno
Registered User
 
Zeno's Avatar
 
Join Date: Aug 2002
Location: San Diego, CA
Posts: 106
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by Sazar
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...
I had to jump in here as a programmer to say that you are incorrect. Doom 3's stencil shadows are fully dynamic, fully 3D, and conform to the environment as they should.

What you are seeing (and complaining about) is the result of the light source (flashlight) being very close to the your eye (the camera). If it were exactly at the point of the camera, you would see no shadows at all. As the light source and the camera move away from eachother in 3D space, the projection of the shadow onto the 2D screen (your monitor) will become more distinct from the projection of the shadow caster. Because the light source and eye are at nearly the same spot, so the projections are nearly the same and you get the flat appearance of the shadow. The same thing would happen in real life! Try putting a flashlight by your eye in an otherwise pitch black room and see how the shadows look.

Another way to see that the shadows are correct was mentioned above: look at the shadows cast by another player's flashlight, or set your in-game camera to be behind and above your character....I seem to remember a post here explaining how to do that. Then you will be able to see the shadows wrapping around the environment like you want.

I've implemented stencil shadows before, and it would be far more difficult to have them floating out in space like you are suggesting than to do them correctly.
Zeno is offline   Reply With Quote
Old 08-03-04, 03:18 PM   #15
Zeno
Registered User
 
Zeno's Avatar
 
Join Date: Aug 2002
Location: San Diego, CA
Posts: 106
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by ClosetFanBoy
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?
Your flashlight does cast a shadow if you have shadowing turned on, it may just be hard to see sometimes because it is almost blocked by the object casting the shadow (see my post above).

For whatever reason, your own shadow is only turned on in multiplayer. Not sure yet why they decided to turn it off in single player. I bet there's a console command to enable it, though....
Zeno is offline   Reply With Quote
Old 08-03-04, 03:21 PM   #16
Clay
Registered User
 
Clay's Avatar
 
Join Date: Oct 2002
Posts: 4,992
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

After further review...

It's obvious that these shadows are not "floating"...if that were the case then you would not clearly see this depth of field difference at play on the edge of the box shot (zoomed in to point it out). You can see that the shadow "after" the box is further away...just as it should be...

__________________
SLI GeForce 7800 GTX 512MB @ 550/1700 | MSI K8N Neo4/SLI | A64 X2 4400+ Toledo | CORSAIR XMS 2GB (2 x 1GB) TwinX PC 3500 | Silverstone ST65ZF 650W| 93.71| XP SP2 and a Dell 2405FPW

I personally believe that us americans are unable to do so because osama.

People out there in our nation don't have that, And I believe that our education like such as south africa and such as the Iraq.

everywhere "such as". And I believe our education should help the US should help the south africa and the iraq and the asian countries so we can build up our future.
-- Miss Teen South Carolina

Clay is offline   Reply With Quote
Old 08-03-04, 03:27 PM   #17
ClosetFanBoy
Thorazine shuffle
 
ClosetFanBoy's Avatar
 
Join Date: Apr 2004
Location: Elk Grove Ca.
Posts: 829
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by Zeno
Your flashlight does cast a shadow if you have shadowing turned on, it may just be hard to see sometimes because it is almost blocked by the object casting the shadow (see my post above).

For whatever reason, your own shadow is only turned on in multiplayer. Not sure yet why they decided to turn it off in single player. I bet there's a console command to enable it, though....

thank you sir.
__________________
In order to find his equal a man is forced to converse with God.

iPhone junkie...
ClosetFanBoy is offline   Reply With Quote
Old 08-03-04, 03:29 PM   #18
CaptNKILL
CUBE
 
CaptNKILL's Avatar
 
Join Date: Jan 2003
Location: PA, USA
Posts: 18,844
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by Zeno
For whatever reason, your own shadow is only turned on in multiplayer. Not sure yet why they decided to turn it off in single player. I bet there's a console command to enable it, though....
Its probably because the AI doesnt react to the players shadow, so it would look strange having your shadow cast into the view of an enemy and have him not respond.

In multiplayer however, shadows can give away the position of an opponent, so it makes sense to have them there.

And im still a bit skeptical of the whole floating shadow thing.

Theres a command for a 3rd person view right? If you turn that on, the truth will probably be revealed (unless the shadow "floating" distance changes for that view).

If it is true however, it almost HAS TO BE limited to the players flashlight, in single player only. Then of course, this doesnt make any sense... bah...

wheres carmack when you need him

EDIT: Sazar, is there any way you can take a screen shot of that exact scene with the flashlight off? Im talking about the one with the railing and the crate (the one clay just quoted).
__________________
---- Primary Rig ---- CoolerMaster 690 II Advance - Gigabyte GA-EP45-UD3P - Intel Core 2 Quad Q9550 @ 4.0Ghz + Thermalright Ultra 120 Extreme
6GB DDR2 @ 942Mhz 5-5-5-20 1.9v (2x1Gb Wintec AMPX PC2-8500 & 2x2Gb G.Skill PC2-6400) - EVGA Geforce GTX 470 @ 750/1500/1850 (1.050v)
Sparkle Geforce GTS 250 1Gb Low-Profile (Physx) - Crucial RealSSD C300 64Gb SSD - Seagate 7200.12 500Gb SATA - Seagate 7200.10 320Gb SATA
ASUS VW266H 25.5" LCD - OCZ GameXStream 700W PSU - ASUS Xonar DX - Logitech Z-5500 5.1 Surround - Windows 7 Professional x64
---- HTPC ---- Asus M3A78-EM 780G - AMD Athlon X2 5050e 45W @ 2.6Ghz - 2x2GB Kingston PC2-6400 DDR2 - Sparkle 350W PSU
Seagate 7200.10 320Gb SATA - Seagate 7200.10 250Gb SATA - Athenatech A100BB.350 MicroATX Desktop - Creative X-Fi XtremeMusic
CaptNKILL is offline   Reply With Quote
Old 08-03-04, 03:31 PM   #19
Clay
Registered User
 
Clay's Avatar
 
Join Date: Oct 2002
Posts: 4,992
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by Sazar
just a little investigation into doom 3's shadow rendering technique...
Hey since you obviously have Doom 3 now... how's about some more examples of this for everyone's consideration?
__________________
SLI GeForce 7800 GTX 512MB @ 550/1700 | MSI K8N Neo4/SLI | A64 X2 4400+ Toledo | CORSAIR XMS 2GB (2 x 1GB) TwinX PC 3500 | Silverstone ST65ZF 650W| 93.71| XP SP2 and a Dell 2405FPW

I personally believe that us americans are unable to do so because osama.

People out there in our nation don't have that, And I believe that our education like such as south africa and such as the Iraq.

everywhere "such as". And I believe our education should help the US should help the south africa and the iraq and the asian countries so we can build up our future.
-- Miss Teen South Carolina

Clay is offline   Reply With Quote
Old 08-03-04, 03:36 PM   #20
Zeno
Registered User
 
Zeno's Avatar
 
Join Date: Aug 2002
Location: San Diego, CA
Posts: 106
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by Clay
Hey since you obviously have Doom 3 now... how's about some more examples of this for everyone's consideration?
Guys, you're chasing ghosts here. You cannot "cheat" on stencil shadows. It uses the depth buffer that's already been laid down by the objects in the scene, combined with the silhouette of the object extruded away from the light source in 3D to define the shadowed regions in screen space. It is a physically correct model for point lights.

P.S - Nice observation in the pic above, Clay. Another thing to notice is that the shadow strip is "thicker" on the floor even though it's further away because it is at more of a glancing angle to the light than the box is.
Zeno is offline   Reply With Quote

Old 08-03-04, 03:47 PM   #21
Zeno
Registered User
 
Zeno's Avatar
 
Join Date: Aug 2002
Location: San Diego, CA
Posts: 106
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

Quote:
Originally Posted by CaptNKILL
Its probably because the AI doesnt react to the players shadow, so it would look strange having your shadow cast into the view of an enemy and have him not respond.

In multiplayer however, shadows can give away the position of an opponent, so it makes sense to have them there.
Ahh, good call. I'm sure you're right. It would be tricky to tell if a monster could "see" the shadow....you'd almost have to render the scene from the monster's point of view to get that info. Multiplayer takes care of that problem, as the shadows ARE rendered from everyone's point of view.
Zeno is offline   Reply With Quote
Old 08-03-04, 03:49 PM   #22
Clay
Registered User
 
Clay's Avatar
 
Join Date: Oct 2002
Posts: 4,992
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

FYI...Check Kamel's thread over here...seems like he is about to post some more good info on the console commands.
__________________
SLI GeForce 7800 GTX 512MB @ 550/1700 | MSI K8N Neo4/SLI | A64 X2 4400+ Toledo | CORSAIR XMS 2GB (2 x 1GB) TwinX PC 3500 | Silverstone ST65ZF 650W| 93.71| XP SP2 and a Dell 2405FPW

I personally believe that us americans are unable to do so because osama.

People out there in our nation don't have that, And I believe that our education like such as south africa and such as the Iraq.

everywhere "such as". And I believe our education should help the US should help the south africa and the iraq and the asian countries so we can build up our future.
-- Miss Teen South Carolina

Clay is offline   Reply With Quote
Old 08-03-04, 03:51 PM   #23
Sazar
Sayonara !!!
 
Sazar's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 9,297
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

sry I was playing the game

wrt to the shadows stay posted for a few more examples of what I am talking about.. it does not appear to be the same case with all the models... it just depends on their location...

I'll try and post to give an idea of what I am talking about in more detail

-edit-

since making the initial post I have played through a fair deal of the game and this is basically what I am seeing (keeping in mind other comments posted)

the shadows are being rendered correctly for the most part (I have been going back and checking them after clearing out the various areas) and generally the shadows are being rendered accurately... they vary according to distance/intensity/background and the like...

in some situations such as what I have pointed out (and that I do see coz there are a fair deal of railings in the game) it appears to just be a floating shadow...

I am not as advanced a programmer as some others out there... but it would appear that in certain situations, certain objects are not rendering accurate projections of shadows...

the floating effect I mentioned can be seen in the shots I have posted... I think
Attached Thumbnails
Click image for larger version

Name:	doom 3 pre-stenciled shadow.JPG
Views:	206
Size:	76.1 KB
ID:	7303  Click image for larger version

Name:	doom 3 pre-stenciled shadow2.JPG
Views:	168
Size:	47.3 KB
ID:	7304  

Last edited by Sazar; 08-03-04 at 04:09 PM.
Sazar is offline   Reply With Quote
Old 08-03-04, 04:07 PM   #24
Nv40
Agent-Fx
 
Nv40's Avatar
 
Join Date: Aug 2002
Location: everywhere
Posts: 2,216
Default Re: Doom 3 pre-rendered "dynamic shadows" ?

interesting topic.

as other have said all Doom3 shadows are dynamic and in real time.. (cough).. hehe. well maybe 90% of all of them are. Doom3 can also use lightmaps if you want ,and projected shadows a quick hack to simulate Softshadows. but also if you want all your shadows can be 100% generated in realtime.(i have seen levels that way) but it will look ugly and unrealistic in some situations .the control is all there in the editor .its up to the level designers what they want to do.Stencil shadow volumes (most of doom3 shadows) is not the be all for all shadows situations ,there are situations where stencil shadows will not be apropiated for some situations. read Unreal3 engine specs , it use MAny diferent shadows techniques for many diferent situations. becasue no technique with shadows yet exist that will be good enough for every single situation in a game. the main player shadows i think are disable by default for performance reasons ,but you can enable them witht the console.
Nv40 is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


Similar Threads
Thread Thread Starter Forum Replies Last Post
Remastered Doom 3 BFG Edition Game Coming with Stereo 3D Support News Archived News Items 0 06-01-12 05:30 AM
Doom 3 BFG Edition will feature entire Doom series, seven new Doom 3 levels News Archived News Items 0 05-31-12 05:40 AM

All times are GMT -5. The time now is 12:02 PM.


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