I saw the included video only now. They do trace area shadows, and its very impressive overall to me. (just to correct myself)
Next gen lighting technologies - voxelised, traced, and everything else *spawn*
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DavidGraham
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It does shadows too. Support for GI is incoming in a future version.
This we have to figure it out by ourselves. By reverse engineering the screenshots.
The photo of the text in black is from the dev explaining the video demo. I like how he is very honest explaining the artifacts and repeating it is not GI.
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DavidGraham
Veteran
No, by reading and listening about what the developer and NVIDIA actually say, they both stated Metro supports only RT GI and RT AO. No RT shadows was ever mentioned whatsoever.
Not really. The limitation to skylight only has been mentioned officially, also the exclusion of dynamic objects, IIRC. (Edit: some objects - not all)
I made a link to some NV site here some pages before. They said this honestly, even if the given reason for the skylight limitation, 'including more lights would have affected stealth gameplay' sounds like a bad excuse maybe.
I say this because you sound pretty disappointed by what was promised, and what have been delivered so far.
I assume this is what many people think after seeing the dancing robot / Star Wars videos, and then looking at Metro.
Also i'm probably the last one here defending RTX,
but we try to value RTX for what it is, not by what was promised from marketing videos.We all know game trailers look better than the final games too, RTX yes or no. If there is something wrong with this, then it is on the marketing side, not on the tech or development side which is main topic here.
So, like the Mod i suggested you may want to add your arguments for discussion.
Oh, so UE4 demo runs only at 5-10fps. Very interesting! (i did not get the connection just by looking at the images - i was mostly confused
)It is not mentioned in the interviews I made since it was not one of the direct questions, but the excuse that having the GI from every light impacted stealth gameplay is in fact the real reason why it is not in Metro Exodus - not because of performance or something. Their technique allows for GI from many more things than the sun and sky, it is just that the sun sky GI did not dramatically alter those areas of the game where stealth gameplay was big.
Also, what objects are you talking about that do not affect or get affected by ray tracing that was officially named? I was not briefed on that at all when I interviewed the devs and cannot think of any obvious instances.
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Is there any useful information on this? i.e.
Does he voxelize the scene every frame? Don't think so. State of the art, well, perf wise, in this field is hardware accelerated voxelization via multi projection and conservative raterization features of Maxwells 2nd gen+ NV GPUs
If he does voxelize the static scene every frame (which I am pretty sure he doesn't do), what algo does he use then to beat the state of the art voxelization, which NVIDIA has been using for quite a while? Even with Maxwell 2 gen's conservative rasterization and multi projection, it's still a slow process, 750 Ti doesn't support CR and multi projection, which accelerate voxelization by 3 times, it uses slow geometry shader emulation path instead
If he doesn't use slow geometry shader emulation of conservative rasterization, then his voxelization is pretty much screwed (holes in voxels coverage)
The scene in the video is completely static, very simplistic and low poly, it doesn't look like the moving curtain affects indirect ligting at all (it would have been pretty expensive to voxelize this moving curtain as standard triangle geometry, unless some hacky algo is specifically used to voxelize it), so one can achieve similar multi bounce effect with RT by caching indirect lighting via texture space shading.
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Where did you get this? Based on my gaming experience in this game, RTGI works for all dynamic objects - train, characters and so on
It's not a limitation, GI for spot lights has been disabled to preserve stealth gameplay mechanics.
If defending RTX is to spread wrong info about RTX implementations in different games, then you are doing it right, sorry
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Yep this is my whole point.
The abuse of the therm "GI" and "Realistic" hurts me too. It hurts me as a dev. Because people seeing my demo could tell me: "This can't be "GI". It looks nothing like Metro.".....
We can't jump to conclusions. Common sense tells us that if GI was enabled from every light, it would have a performance impact. We just can't know how much.
Personally i do not accept it for this reason: RTX adds much darkening with its AO. This darkening affects stealth game play a lot more than some bounce light. Additional bounce light would only help to leverage this effect.
But this is just personal opinion. I would not want this to become topic of public discussion. They may be just honest and i'm wrong. The assumption 'More lights would have been too expensive' makes no sense either, even less sense for me.
I assume the real reason could be too much necessary manual tuning work on the light settings, or a need for some data structure to know which lights affect which parts of the scene. And they did not have enough time.
I'm really just guessing here!
If you look at this image image with the couple sitting on the small table beside train window, you can see the objects on the table (cup, gun, lamp) to not emit ambient occlusion, because they are not included int scene for RT.
They only receive AO, because rays start from the rasterized screenspace pixels. If you look close, it seems even the table itself is ignored (legs would be darker).
Why did they exclude this? The Table is surely not dynamic, so no additional BVH building cost? I guess maybe because it would have become too dark otherwise. (We saw some shots where AO caused bad dark faces but hair remained bright - unexpected problems are expected when adding RT to a game not meant for it.)
In the interview with devs from Metro, they said explicitly that with RT it is all much more easier for the developer.
(By the way- what is this stealth argument about?! Metro is a single player game. Should the corner be darker in order the NPC be unable to see the player in the dark?!?)
He has description on the gamedev.net site i have linked. I assume he only voxelizes dynamic stuff (curtain). I had 80 fps, but ofter adding curtain it dropped to almost half of that. The curtain iluminates the scene, IIRC. (The demo is downloadable)
Sigh... if i'm wrong then not because i would lie to talk RTX down. I'm sometimes wrong, as you know, but my motivation only is flexibility, prefer compute over FF, make sure RT FF is really needed before throwing it to the market in a big surprising act. If FF, then expose at least as much as possible.
That's all. Please see the screenshots yourself. It's obvious. the shot was posted here weeks ago, an i immideately spttd the cup is floating because it casts no AO. Look yourself before accusing me such BS please!
Edit: And check the link to NV blog. They mention exclusion of objects, e.g. foliage. I knew it before as well because it's visible in the old dev video.
Response:
"Fermat 2.0 introduced support for more complex materials and better samplers so one can't compare results with our previous results with Fermat 1.0. v2.0 produces less noise per sample with complex lighting."
Well foliage is most definitely included in the retail product, I even mention it in my video (16:46 or so) with a clear example (and there are many others I have in my collection of footage) - the version of technique shown around Gamescom was really rather different in performance and how it functions based upon everything I saw and what I was told.
That's cool, the interesting stuff is whether he uses some general algo to voxelize the curtain and which can be applied to any triangle geometry in any game or whether he built some specific algorithm to speed up voxelization by working with the physics engine spheres representation of geometry.
But you can see the cup and agree with me? Image just one page up in NikiTos post.
You guys drive me crazy sometimes. Sometimes i argue with other dev when he says 'Games are just smoke and mirrors'. He's right. This is how games work and people do not spot it.
It's even more crazy i get attacked for exposing such obvious tricks, and the same would apply to accusing this to Metro devs. Nobody ever promised it would be perfect and accurate - almost nothing is.
http://screenshotcomparison.com/comparison/130818
On this screenshot from devs, I can see all kitchenware is affected by RT
On this screenshot from devs, I can see all kitchenware is affected by RT
This is why I don’t/stopped reverse engineering screenshots. Unless you have the metro devs come in here and tell you what’s happening, it’s a pointless discussion. There are just too many factors that can be happening behind the scene that you may not know of. I do agree that sometimes there are glaring issues, but DF will also catch that as well.
Overall not worth it your energy to chase this imo. In Your case
If the words, global, or universal aren’t used assume that it can be modified per object or per see or per mesh etc.
Reminder: rendering devs are not world builders. They don’t make the call for every single scene.
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Indirect shadows are the direct result of how GI works
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