Shadow casting explanation for non-programmers

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Originally posted by Styloid
Doom 3 doesn't shadow some objects either if you look at some of the screen shots- trites' head don't shadow onto its legs. Objects can be selected as to whether it shadows from a certain lightsource or not.
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I don't know where you got your info, but Carmack always said the lights and shadows in Doom3 would be 100% consistent.
The trite you're talking about does cast a shadow onto the environment for every light. The only thing I question is whether it has any self-shadowing (shadow from the head onto the leg).
The hell knight in the latest released picture does have self-shadowing for sure. Maybe it's some kind of detail setting that you can switch on and off in Doom3.
 
HL2 has radiosity, just not in real time. It's calculated when the maps compiled.
 
Is it even possible to do real-time radiosity calculations? It would be a major system load.
 
Originally posted by ElFuhrer
Is it even possible to do real-time radiosity calculations? It would be a major system load.
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that raytraced engine can do it, the one that works entirely in software mode without any special hardware tricks. But its slow, and its probably low radiosity, unlikely more than one bounce. I said it couldn't/wouldn't be done for atleast a few years, I was wrong.. Entirely unplayable though right now, once you've got NPC's and so on going in such a thing, but its being done right now so who knows :)
 
Current top-end graphics cards can render low resolution (256x256) radiosity at about 2 fps.

-From a PC mag.
 
Originally posted by Arno
I don't know where you got your info, but Carmack always said the lights and shadows in Doom3 would be 100% consistent.
The trite you're talking about does cast a shadow onto the environment for every light. The only thing I question is whether it has any self-shadowing (shadow from the head onto the leg).
The hell knight in the latest released picture does have self-shadowing for sure. Maybe it's some kind of detail setting that you can switch on and off in Doom3.
Click to expand...

I read it in an interview/preview but it was a while ago so I'm not sure it's still accurate or if I can dig it up. I'm still pretty sure that it still applies because of the screen shots of the trite (I think self shadowing is part of the unified lighting system). I certainly hope D3 allows me to turn off some shadows when I eventually try running it on my computer for optimization sake. I'm just saying that a plank missing its shadow right now is no big deal. If its missing in the final version.... it's still no big deal really.... but I'm sure some one could make it one.
 
Only problem with those renders is that horrible (is it meant to be marble?) mirrored texture.
 
Originally posted by Fenric1138
that raytraced engine can do it, the one that works entirely in software mode without any special hardware tricks. But its slow, and its probably low radiosity, unlikely more than one bounce. I said it couldn't/wouldn't be done for atleast a few years, I was wrong.. Entirely unplayable though right now, once you've got NPC's and so on going in such a thing, but its being done right now so who knows :)
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I can't wait till the day skin and clothing in games are rendered with SSS, and everything rendered using radiosity, HDRI used for every reflection at high resolutions...

*faints*
 
Originally posted by PvtRyan
I can't wait till the day skin and clothing in games are rendered with SSS, and everything rendered using radiosity, HDRI used for every reflection at high resolutions...

*faints*
Click to expand...

I saw a great use of SSS last night, atleast it certainly looked to be a CG shot. Stargate season 7, that space race episode, cr*p storyline but the chunks of ice in space looked amazing, either they'd filmed actual chunks of ice as practical models and comped together to create the scene (possible but unlikely) or it was 3d digital mattes (possible) or it was CG with SSS for the ice effect, it was really well done however they did it, makes a change from always seeing statues or glass animals done with SSS thats for sure ;)
 
Guys, I just Spoted the Doom3 Box at a games store near my university:
 
Originally posted by G0rgon
Guys, I just Spoted the Doom3 Box at a games store near my university:
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coolies :)

looks like it has Invader Zim's doom song lyrics on the back ;)
 
Yeah, they came out with that promo crap on the 1st of Nov.
What's weird is that at my Gamestop, they're including the Baron of Hell, not the Pinky Demon. o_O.
I guess they're sending out different statues to different areas, bastards; I want the Pinky Demon, damnit!

Anyway, back to shadow casting! :)
 
:)

Originally posted by GhostValkyrie
Yeah, they came out with that promo crap on the 1st of Nov.
What's weird is that at my Gamestop, they're including the Baron of Hell, not the Pinky Demon. o_O.
I guess they're sending out different statues to different areas, bastards; I want the Pinky Demon, damnit!

Anyway, back to shadow casting! :)
Click to expand...

Hmm I haven't seen any of those boxes in Denmark... But I haven't been looking for them... I want one too :-/ oh well Im'a go home and look at my 1600x1200 D3 screens =D

I think the shadows in D3 are a bit too exact, I mean normally(in the real world :O ) a shadow are never that black to the edge they usually turn more light at the edges... Even though there only are one lightsource? Anyways I think they are exellent! But Id still want HL¹ shadows and high detail charecters more than the opposite.
 
I think it will take 3 to 5 years for radiosity to be rendered in real time in a game if it can be done at 1 to 2 fps now. My new computer can render UT2003 at about 70-100 frames per second on the highest settings with 8x AF, but my 5 year old computer can only render it at about 10-15 fps on pretty low settings.
 
Re: :)

Originally posted by _-_-SELAS-_-_
Hmm I haven't seen any of those boxes in Denmark... But I haven't been looking for them... I want one too :-/ oh well Im'a go home and look at my 1600x1200 D3 screens =D

I think the shadows in D3 are a bit too exact, I mean normally(in the real world :O ) a shadow are never that black to the edge they usually turn more light at the edges... Even though there only are one lightsource? Anyways I think they are exellent! But Id still want HL¹ shadows and high detail charecters more than the opposite.
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Recently, they implemented Soft Real-time shadows. THese looks very impressive, and a hell of a lot more realistic. Halo 2 has done the same thing.
 
Originally posted by iamironsam
So they actually create multiple layers of translucent "skin" that react to the "light" in with differing degrees of reflection? Could they take samples of light rotating around the model and create a sort of bump mapped texture based on the information?
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No it's not that complicated really, it's just a shader effect. Atleast, the ones I know are. The wax material from Brazil (max renderer) uses SSS. You just input the color, the sheen color, the color just below the surface and the deep color and how far the light should bounce in.

I made an example render using SSS and photon mapping. Note the color bleeding on the cube from the walls.
 
Re: Re: :)

Originally posted by GhostValkyrie
Recently, they implemented Soft Real-time shadows. THese looks very impressive, and a hell of a lot more realistic. Halo 2 has done the same thing.
Click to expand...

I heard they had done that but I havn't seen any evidence yet.
 
Re: Re: :)

Originally posted by GhostValkyrie
Recently, they implemented Soft Real-time shadows. THese looks very impressive, and a hell of a lot more realistic. Halo 2 has done the same thing.
Click to expand...
WOW sounds cool have ya n e nice screenies? =)
 
An example of the Soft Real-Time Lighting can be found here.

It's not straight in your face obvious, because it's simply there...looks more realistic.

BTW: It also appears Bungie has implemented reflections on the Covie armor!
EDIT: Looking at it ever so closer I noticed that the weapons reflect as well...I haven't seen this pic in so long I had forgotten. The teeth need some work though...

Enjoy!
 
Is Halo 2 full dynamic? Or does it have some static lights?
 
Not too sure. It seems like there are, if you watch the Demo vid closely.
I'm guessing when the model isn't in an area of real-time lighting or shadows, the shadows are static. But Bungie was talking about everything being real-time when it's finally realesed. This way they can have destructible environments that don't looke like crap...
/me looks a Red Faction 2.
 
Unless I'm mistaken, I think you can have dynamic shadows for an object moving under a static light, can't you? The only problem is that the light can never move. So realistic environment destruction could look good under a static light.
 
Only not. I'm ambivalent about the covenant model in that pic - while I like the lowpoly head spikes (they remind me of halo 1, and they make the elite somehow more familiar... i dunno) The simple low-poliness of it I don't like. I can't wait to return to halo through the time portal and talk to the monitor before he goes senile!
 
Originally posted by FictiousWill
Only not. I'm ambivalent about the covenant model in that pic - while I like the lowpoly head spikes (they remind me of halo 1, and they make the elite somehow more familiar... i dunno) The simple low-poliness of it I don't like. I can't wait to return to halo through the time portal and talk to the monitor before he goes senile!
Click to expand...

That's what I don't really like about Halo. It used a lot of shinyness and effects to make up for the overall lack of detail. The furthest level that I got to on Halo (it's the covenant ship with the captain on it) was absolutely horrible. It was a few shiny, non-detailed textures repeating down long hallways that every once in a while opened in a big chamber with a few carbon-copy enemies thrown in. I've heard people talking about a "library" that's really boring and endless, I hope it's not worse than the level I'm talking about.

Back to the subject at hand can anyone correct me if I'm wrong on the dynamic shadows under static lights thing? I'm really not sure, and I'm no expert on this. I'm curious myself about what I said.
 
Originally posted by ElFuhrer
That's what I don't really like about Halo. It used a lot of shinyness and effects to make up for the overall lack of detail. The furthest level that I got to on Halo (it's the covenant ship with the captain on it) was absolutely horrible. It was a few shiny, non-detailed textures repeating down long hallways that every once in a while opened in a big chamber with a few carbon-copy enemies thrown in. I've heard people talking about a "library" that's really boring and endless, I hope it's not worse than the level I'm talking about.

Back to the subject at hand can anyone correct me if I'm wrong on the dynamic shadows under static lights thing? I'm really not sure, and I'm no expert on this. I'm curious myself about what I said.
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Yup, much worse it was just like playing the same 2 small maps again and again and again like I was a big duracell-fukkin-bunny :) zzZZzZ
 
Am I the only one who think the character shadows in Max Payne 2 are absolutely amazing?
 
Anyone mind if I talk about the shadow techniques intro'd in the header?

1. Shadow volume generation - nice looking (very realistic), but takes a lot of CPU power to compute. Every single polygon casts shadow, that clips every poligon behind (in the line from lightsource).

That method actually looks VERY good. In fact, I even devised a little (read: big) change in it such that multiple shadowing can be done using that.

2. Stencil buffer shadowing - very efective for less lightsources. Scene is rendered from the view of every lightsource with only visibility that counts (no color, no shading). Information about visibility from this rendered plane is vital for determine whether pixel is behing some face or not.

Isn't this and #1 supposed to be combined?!

3. Texture shadowing - nice looking (makes soft shadows possible) shadowing technique. Calculating shadow for every polygon and multitexturing is the point here. Not very fast, but worth implementing (take a look at Splinter Cell).

SC is probably the best example, but every other time I've seen it in a game it looks like ass, because it's very blocky, and the ability to make TRUE soft shadowing is virtually impossible. The worst technique out there (although JK2/3's shadowing is probably far more ass than this one)

4. Ray tracing - extremely realistic technique. Requires casting rays of light from every lightsource, calculating reflection, etc. Slooow on every machine.
There is smth called energetic method, but it's used in 3D programs, like Softimage, 3DStudio or so only.

And this is the reason why it takes tens of hours to render a single frame of CG animation.
 
Originally posted by PvtRyan
No it's not that complicated really, it's just a shader effect. Atleast, the ones I know are. The wax material from Brazil (max renderer) uses SSS. You just input the color, the sheen color, the color just below the surface and the deep color and how far the light should bounce in.

I made an example render using SSS and photon mapping. Note the color bleeding on the cube from the walls.
Click to expand...

Thank PvtRyan. I didn't know it was as simple as that. Those shader effects don't look complicated at all, no more complicated than those used to soften the edges around "bright" light in HDR. I wonder why no ones used them yet.
 
Originally posted by FictiousWill
Only not. I'm ambivalent about the covenant model in that pic - while I like the lowpoly head spikes (they remind me of halo 1, and they make the elite somehow more familiar... i dunno) The simple low-poliness of it I don't like. I can't wait to return to halo through the time portal and talk to the monitor before he goes senile!
Click to expand...

I agree, the models in Halo and Halo 2 are very low poly and dated looking. But you have to keep in mind that they're developing them to run at 30fps on a system equivalent to a P3 700mhz with a GF3. I think our standards are a bit higher.

Originally posted by CrazyHarij
Am I the only one who think the character shadows in Max Payne 2 are absolutely amazing?
Click to expand...

I don't think so. High res textures on low poly models look ok from a distance, but once you get up close they look awkward. I like the effects used to make materials like leather look more realistic though.
 
Nevermind about my response to CrazyHarij, I missed the word shadow in there. It's still early.
 
That Halo 2 shot is seriously dodgy, the xbox won't run at that kind of rez with AA turned all the way up at more than 10-15fps. The textures arn't too good either, compared to the video where the green guy jumps out of the ship that screen is very disapointing.

What I really want to see is some D3 soft shadows.
 
Originally posted by mrchimp
That Halo 2 shot is seriously dodgy, the xbox won't run at that kind of rez with AA turned all the way up at more than 10-15fps. The textures arn't too good either, compared to the video where the green guy jumps out of the ship that screen is very disapointing.

What I really want to see is some D3 soft shadows.
Click to expand...

Does X-Box even have AA?
 
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