And add RDR to the list, MOH does have it too indeed. I also think manually placed godrays look a lot more beautiful as they can be greatly exaggerated without following a specific algorithm. Both have pros and cons though.God of War 3 have awesome godrays, even some attacks create godray casting light sources, you can even have 2 of them on the screen at onceFor multiplatform games, I know about: Far Cry 2, Just Cause 2, Crysis 2. I'm not sure about MOH, but it's running on the same version of UE3, no (with GI, cascaded shadows etc.)?
I always wondered what is the performance cost for godrays on consoles and what's the difference between this technology and volumetric lighting (like in Alan Wake)?
Digital Foundry Article Technical Discussion Archive [2011]
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I haven't seen many games with 'true' real-time godrays/sunshafts, though. I think both STALKER: CS and CoP have them.
SedentaryJourney
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Could you be more specific as to what 'true' real-time godrays are?
Good question. As far as I could tell from the AW footage posted in the game technology thread there doesn't seem to be a difference in terms of visual effect.
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I'm actually thinking of proper volumetric lighting, but looking at videos of CoP it just seems to be a screen effect like usual, lthough I remember seeing a screenshot showing a beam of light streaming through a window and across the room, illuminating dust, etc.
Did Crysis have volumetric lighting as well?
http://www.youtube.com/watch?v=mHuYIE1kNOk&feature=player_detailpage#t=180s
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(((interference)))
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Oops, yeah that's what I meant.
I highly doubt that...
It makes absoulutely no sense that the PS3 version is using full res transparencies while the 360 isnt - especially since the 360 doesn't have any additional transparency effects to compensate for the deficit. Otherwise there are hardly any differences between the two, (except from some minor advantages in water effects and shadow filtering on 360) so all the more surprising that the 360 loses out in transparencies when pretty much every other time, the opposite is true.
http://www.eurogamer.net/articles/digitalfoundry-faceoff-battlefield-bad-company-2?page=2
Is it more likely that on PS3 they're running some kind of filter to blend the transparencies, perhaps on the SPUs? Has a game done something like that before?
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That repi tweeted it or that the artists preferred A2C?
The use of A2C has nothing to do with resolution. It's just the alpha coverage mask ANDed with the MSAA coverage mask.
No, they're just alpha tested.
Taking repi's word at value, you have to look at the use of A2C (effectively dither result with single sample per pixel) from the standpoint that they're going to be using a lot of said textures. Again... think of your typical insect screen door and think about what happens when you put a ton of them together, overlapping, and then change your own view distance. Doesn't mean that everyone's going to like it or that it ends up being ideal.
Great disappointment about the ps3 'updating'... I'm not want to be misunderstanding how to blame the developers, it isn't my really intention, but what exactly has updating the last version of ue3.0 on the ps3 sdk? The SSAO is absent, the light are simplies bloom effects and even MLAA implementation seen in Dragon Age 2 lack... it isn't the same ue3 version seen for a years on a ps3?
It seems so ancient compared to 360 'grow'...
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You said "usually"
Is it reaaaallyy that usual?
FF13 has nice god rays tooGod of War 3 have awesome godrays, even some attacks create godray casting light sources, you can even have 2 of them on the screen at once
I always wondered what is the performance cost for godrays on consoles and what's the difference between this technology and volumetric lighting (like in Alan Wake)?
I know about Borderlands and Bullestorm, eery other game with this effect has it on PS3 too.
And this no SSAO pattern... is it even included in PS3 version of the engine? SSAO on SPU's shouldn't be that taxing, no?
No, it's prebaked. And they are using very nice lens flare effect for sun, similar to one in Mass Effect series (i like it very much).
SedentaryJourney
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Interesting anecdote about that, I remember seeing the god rays flickering at one point late in the game. Turns out one of the flying monsters off in the distance was flying through and occluding the rays.
I have read in ND presentation that it took them 2ms across 6 spus but they get it down to 1ms.
L. Scofield
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Yes, it did. It has two types for spotlights. Blurry beams like in your video (performance friendly) and more proper beams that weren't used in game by default but could be activated with the CVar "r_beams 1".
A couple of examples:
http://www.youtube.com/watch?v=RH6cYXk2XYI
http://www.youtube.com/watch?v=6GQwKBZKN54
It also had particles that receive shadows (like GT5).
CoP/Clear Sky has fullres volume beams by slices so they can form 3D volumes like your example with window. Crysis dynamic godrays from sun are 2D.
But I agree with others static godrays can look nice. One good example are the animated statically placed godrays in Fallout 3/New Vegas when indoors. The are animated + has effect to simulate lit up dust/particles in air.
Talking about volume effects, those clouds where plane pass through are true volume effects. I am not talking about layers but a real volume effect. Not sure I remember right now the tech term but something with "pearl". Makes for a solid volume no mather angle in or out of volume. I think thisis a typical CGI movie effect except Crysis did has lower precision/res for effect. Also used pretty well in extraction level where you fly the VTOL. The rest of clouds are volumes by layers.
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AFAIK only difference between r_beams settings is 3=optimised (~1280x720 res PP), 2=Fake, 1=Full res beams slices (same as framebuffer like for example Metro 2033). Both 3 and 1 still have same volume effect with slice distance and max amount of slices set by r_BeamsDistFactor=0.05
r_BeamsMaxSlices=200 (very hgih default).
You get pretty much same effect as in those videos in the alien ship which has lots of such volume lights throughout level.
I personally think light shafts are mostly good for indoors instead of outdoor environment....cause in real life scenario there are only certain conditions (like during the dawn or when the sun is partially hidden by clouds/smoke/dust) under which you'll actually see the Godrays from sun. I think its pretty stupid to see a game where the sun casts God rays for the entire duration of daytime even more when it reacts with your view weapon or character, it shouldn't be like this outdoors...indoors is a different story altogether as volumetric light is the best way to portray a dusty indoor environment.
Most are fakes in two ways. The real old school way is like ME2, Fallout 3, and many other games do by just placing fake god ray geometry in the scene and scrolling some dust texture on it like in this pic:
http://i469.photobucket.com/albums/rr57/coilercat77/c015fd55.jpg
More recently some games like RDR, etc, will fake the rays via post process. There's a version of that shown in Gpu Gems a few years ago here:
http://http.developer.nvidia.com/GPUGems3/gpugems3_ch13.html
...which give that familiar look here:
http://il.youtube.com/watch?v=N6r6tbf4UGU&feature=related
That method though only works for when the sun is visible on screen, then it makes those funky rays that cut through stuff. There's different ways to do it, but if you are rendering in hdr then it's likely you already have some of the buffers needed to create that effect. So on an hdr game on the 360 you can get this effect almost for free, although it's usually done in lower res hence why it often looks a tad blocky. You can do it on PS3 as well, you just need the spu time for it.
The above cheats fail in many circumstances though. For example using fake placed god ray geometry only works well if they are far away to where you can't get to them because if you can walk up to them then you can see that they look totally fake like in ME2, although they can still look cool sometimes. And cheat #2 only works when the sun is on screen. AW's solution is more general light volumes, somewhat more complicated but it means they can be integrated it into gameplay far more often because it doesn't break down like cheats do. You can see it on DF's videos here:
http://www.eurogamer.net/articles/digitalfoundry-alanwake-tech-analysis?page=2
I believe Castlevania does true light volumes as well in one of the levels closer to the end of the game, as you can play with the curtains on the windows to control how the light volume looks to beat the boss guy. Do any other console games do this?
I was going to say. If you have access to the depth buffer, it'd be little effort to write a SPU graphics process to create god rays as a 2D composite and it'd be as quick as any solution I think. I'm surprised more stuff doesn't work in that space TBH. 2D effects can be extremely fast and convincing and are a nigh perfect fit for SPUs.
It does use the depth buffer but it also uses the luminance buffer, something that all hdr games will have lying around for to the tone mapping part, and they usually have various resolutions of it available. Typicaly a lower res version is used, hence why the post process god rays do look a touch blocky sometimes. Yup the spu's live for this sort of thing, they are perfect for it. It comes down to finding the time to implement them, both coding time and spu time.
The reason it's easier to implement on 360 is that it's actually very easy to fit this post process effect into existing gpu post process steps, and in many cases it can slide in close to free by using idle gpu time since it's a unified gpu. You literally just have to edit existing shaders, that's it, I did it in I think two days many a moon ago.
The spu's would slice through this sort of task quickly, but the trickier part is that they have to be available when you need to do it otherwise you risk stalls. A simple example, imagine an spu useage chart like the ones Guerilla has shown, and imagine that they are mostly idle, perhaps just used at 20% or so. If that 20% of time when they are being used just happens to be when you need to be doing the post process god ray work on spu, then you have to wait. By the time you get your hands on an spu, perhaps now the gpu is ready and waiting for your final buffer to blend it all back. Now you have a stall because the gpu is waiting on your spu god ray post process task to complete. That's what makes it more tricky to implement features on a gpu+spu setup, you really have to orchestrate it all together so that the data flow is smooth and predictable. It's also why you tend to favor fixed processing time algorithims on such a setup because it makes scheduling much easier.
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