[Graphics] Could someone please explain Bloom to me?

[Adelheid]

I understood Anti-aliasing once someone explained to me that it was either that or make pixels smaller, and I guess doing something clever like make the pixels itty-bitty takes the kind of genius beyond even Steven Hawking, but I still dont understand Bloom...
What's the point? I can get the same effect by not wearing my glasses, drinking four bottles of Bombardier, or smoking a few spliffs, so is that the point; Bloom was invented so that gaming nerds could trick themselves into believeing they have vices other than gaming?
Hmm...
Perhaps a better question is why do we need it?

[toniglandyl]

well bloom is mostly overused, but it's normally used to show that something is "too bright" or so.
when used properly (read subtly),it's really nice.
I believe HL2 : episode 2 has the best use of HDR/bloom (I don't have crysis, and I don't remember from the demo how the bloom was). try enabling, disabling HDR, you'll notice that the difference is subtle, but it really adds to the general scene.

[Nemephosis]

It's a way of making things look like crap, and it's heralded as a feature.

[Slainchild]

Emphasizes lighting, dunnit.

[GeckoYamori]

http://img181.imageshack.us/img181/7516/hdrposterpz7.jpg

[Banoffee]

^ Haha :D

Yeah, it's really nice when used properly (http://news.softpedia.com/images/extra/GAMES/large/halflife2sp2rew_072-large.jpg).

I personally hate AA and post processing though, to be honest I'd rather see the original image and not one that's blurred to crap and glowing like a christmas tree (http://pnmedia.gamespy.com/planetunreal.gamespy.com/newsimages/ut3hq/large/dm/shangrila1.jpg). It's turned off where possible here. So lazy.

[Nemephosis]

You broke your link, Banoffee.

[Big-Al]

i just don't like the motion blur

[Big-Al]

^ Haha :D

Yeah, it's really nice when used properly (http://news.softpedia.com/images/extra/GAMES/large/halflife2sp2rew_072-large.jpg).

I personally hate AA and post processing though, to be honest I'd rather see the original image and not one that's blurred to crap and glowing like a christmas tree (http://pnmedia.gamespy.com/planetunreal.gamespy.com/newsimages/ut3hq/large/dm/shangrila1.jpg). It's turned off where possible here. So lazy.

http://news.softpedia.com/images/extra/GAMES/large/halflife2sp2rew_072-large.jpg

[SleepyHe4d]

http://img181.imageshack.us/img181/7516/hdrposterpz7.jpg

Woah, I seriously thought that was a modern game at first till I saw the hud.

[Slainchild]

http://img.photobucket.com/albums/v497/Slainchild/879d88e7.jpg

[JohnDoe641]

Bloom is mostly a camera term. I don't know why the decided to add it to video games since it doesn't happen in real life but whatever. :c

[TomWithTheWeather]

Bloom and HDR are totally separate things.

High Dynamic Range lighting - http://en.wikipedia.org/wiki/High_dynamic_range_lighting

HDR rendering is basically a way to render lighting data in a much more realistic way. The range of lighting data is extended to more accurately match the range that the human eye is capable of seeing. With HDR, bright and dark spots are often more accurately rendered, simulating real world lighting, and colors are more accurately portrayed. All this is done on hardware, which is why you need an up to date graphics card with the right shader version to render in HDR. HDR is pretty awesome.

http://en.wikipedia.org/wiki/Image:Farcryhdr.jpg

Bloom - http://en.wikipedia.org/wiki/Bloom_lighting

Bloom is a shader effect that attempts to reproduce the camera effect of bright lights "feathering" or glowing using a blur algorithm, and yes, many developers tend to over exaggerate this effect. But when used sparingly, it can look really good.

[Majik]

I remember the first time I saw bloom utilized in a game when playing Tron 2.0. It really made a world of difference to have it turned on as it made everything look a lot more vibrant and, you know, Tron-ish. I honestly don't think I've seen a better use for it since then.

http://image.com.com/gamespot/images/2003/screen1/529599_20030527_screen001.jpg
http://image.com.com/gamespot/images/2003/screen1/529599_20030527_screen002.jpg

[Rambowjo]

The bloom effect often occurs when you take pictures of plants, like flowers, from what I've heard.

[TomWithTheWeather]

The problem with most Bloom in video games is that is not as high-res as it should be and it's not subtle enough. It's often blocky looking and cranked up way to high. It's often this way because current hardware lacks the performance needed to render bloom at a high enough resolution for it to be realistic. It's often too bright because some developers are too eager to use it as a "next-gen" marketing bullet point.

[T2A`]

The human eye does have a really high range but not all at once. When you look at something bright, everything else goes dim. Conversely, if you're in a darker area, bright things will appear much brighter, often to the point where you can't see any details in the bright stuff. Most HDR in games is used to make bright stuff extra bright and flashy, but the whole "dynamic" part isn't used very much.

HL2 was probably the first game in which I noticed dynamism. You emerge from an indoor area and everything outside is brighter until your "eyes" adjust. Then if you look back into the room you can't see much/anything therein because your "eyes" are adjusted for bright stuff and thus can't see the details in the darker room.

Crysis did the dynamic part very well too. I recall a point in the game where I was running up a hill with some trees and other foliage standing between me and the setting sun. Standing in the shadow of the trees and peering through the gaps in the leaves left little but a nondescript bright orange glow to be seen, but moving past them let all the brightness come down and fill in the details. It looked f**king awesome.

But, yes. Bloom is very dumb. UT3 is a perfect example of how NOT to do it. It does have HDR stuff, but it is completely overwhelmed with crappy bloom.

VERY, VERY BAD.

http://insite.beyondunreal.com/screenshots/1300_4.jpg

[TomWithTheWeather]

The bloom effect often occurs when you take pictures of plants, like flowers, from what I've heard.

For a good example of bloom, grab your camera, go into a dark room with a sunny window, and aim at a dark spot while keeping the window in the frame. Take the picture and look at it on the computer. You'll notice that while the camera to tried it's best to take a picture of the dark area, the window ended being crazy blown out and bright (bloom effect). This is because the current camera technology has a very limited dynamic range. If you just look at the same dark area and window with your own eyes, you'll see that you can accurately see the dark area and what's outside the window without anything being blown out because your eyes have an incredibly high dynamic range.

[MonsOlympus]

What I find interesting is that on that bloom wiki link it says its to reproduce an image artifact on real world lens', kinda makes 0 sense to have in an FPS then since the "camera" is actually meant to be a characters eyes.

Bloom can certainly work but sometimes too many filters can get alittle much and ends up degrading the overall image quality. Some effects and filters are best left when you are trying to capture what a camera would be doing, others are better for what the human eye does.

You need it in UT3 for the emissiveness it seems. I do turn it off in other games though where its not so dramatic, in UT3 when I turn it off I lose the lights on the pickups and stuff. Personal preference really and it does come down to the game and how its used :cool:

[TomWithTheWeather]

But, yes. Bloom is very dumb. UT3 is a perfect example of how NOT to do it. It does have HDR stuff, but it is completely overwhelmed with crappy bloom.

One way of thinking about it is that developers often use the higher dynamic range of the rendered scene to more accurately calculate their bloom effect, though they still often manage to over exaggerate it.

And one note about UE3; the engine is very capable of rendering very nice and subtle HDR/Bloom effects, it's just that Epic does a horrible job with their post processing effects in GoW and UT3. They have no subtlety what so ever, and they probably do it on purpose for some reason. They take every dial and crank it to eleven while dropping the color saturation to an almost B&W state. Quite franky, it makes many of their maps look like ****. They have some really good art, but you can't tell becasue they cover it all up by abusing their own post processing system.

Here is a UE3 engine screenshot with much more subtle post processing. Notice how much nicer the bloom looks in this scene when compared to the UT3 screen that T2A posted?

http://img440.imageshack.us/img440/9219/1212010897tt7.jpg

[SleepyHe4d]

What I find interesting is that on that bloom wiki link it says its to reproduce an image artifact on real world lens', kinda makes 0 sense to have in an FPS then since the "camera" is actually meant to be a characters eyes.

Human eyes are lenses too. Just look directly at a light bulb and notice how it's all blurry around the edges even when you're looking at it from the lit up room. :lol:

[TossMonkey]

http://www.vgcats.com/comics/images/070119.jpg

[toniglandyl]

I sure didn't see that VG cats comic coming :rolleyes:

[Adelheid]

Ah, so bloom was a good idea until some company tried to use it as a penis extention?

Hmm... If you don't rate, over compsensate?

[MonsOlympus]

Human eyes are lenses too. Just look directly at a light bulb and notice how it's all blurry around the edges even when you're looking at it from the lit up room. :lol:

Yeah but the human eye is a fair bit different to a camera lens for eg. Infact if I look at a globe the little dot gets stuck in my vision afterwards because of the way our eyes adjust to light variations. It certainly does get blurry around the edge of a light source, which is where bloom does work but Ive been outside in very hot sun living in the desert and not very many surfaces at all completely white out under intense sunlight.

See the lightsource bit is kewl its what it does to the rest of the screen at the same time, they do it alot in soapies like days of our lives or somethin where everything emits a halo effect for drama. Not only that but they do high contrast in that one, I think twin peaks did it as well without the contrast.

Things Im talking about is like lens flares, corona's do happen under the right atmospheric conditions. I think thats something they should take into account more, volumetric lights can be blurry but they can add to the atmosphere when used correctly.

[TossMonkey]

I sure didn't see that VG cats comic coming :rolleyes:
Well unlike you I have actually contributed towards the actual subject of the thread. Perhaps you'd like to keep your sarcasm to yourself?

[8-4-7-2]

HL2 was probably the first game in which I noticed dynamism. You emerge from an indoor area and everything outside is brighter until your "eyes" adjust. Then if you look back into the room you can't see much/anything therein because your "eyes" are adjusted for bright stuff and thus can't see the details in the darker room.
Yeah, that was great. Using it like that is pretty awesome :)

But there is really no point in just blooming up every static surface for no reason at all. Or UT3 has pretty much uniformly white glowing skies, no matter where the sun is. Sometimes it seems that Unreal had better skyboxes than that.

[Jacks:SmirkingRevenge]

http://xs321.xs.to/xs321/07485/kabloom.jpg

[Jacks:SmirkingRevenge]

Someone said a good example of HDR and post-process bloom was HL2:Ep2 and were unsure about Crysis.

Well, here's some of that.

bright, low sun hitting the hut and objects out front, brightening tree tops
http://www.incrysis.com/wiki/images/6/6e/HDR_bloom.jpg

light glow behind the green leaves and shadows coming through
http://www.incrysis.com/wiki/images/5/56/Subsurfacescattering.jpg

explosion against a bright, midday sky
http://www.incrysis.com/wiki/images/f/fe/3D_Ocean.jpg

[MonsOlympus]

http://www.incrysis.com/wiki/images/6/6e/HDR_bloom.jpg

Prime eg there of that whiteout I was talking about, it seems the light drains every last detail from the surface and leaves almost just a plain white patch. Even if the surface has details in it which would be like a shadow, ofcoarse white materials emit some light which will bounce off other nearby surfaces but this gives the impression its glowing which a matte material wouldnt do. With the amount of sunlight an bloom in that scene you would expect more volumetrics from stuff in the air for the light to bounce off.

Yeah that shotgun looks untextured from here as well :p

http://www.incrysis.com/wiki/images/5/56/Subsurfacescattering.jpg

This shot looks much better I rekon! You can see the distance being fogged out alittle and the other volumetrics coming in across ways from the top of the mountains the leaves are getting alittle whiteout but alot more consistant with the overall scene. For leaves you would expect more white out than a matte material because of the layer of liquid inside the leaves and the glossy green exterior :cool:

[FaT CaM]

VERY, VERY BAD.

http://insite.beyondunreal.com/screenshots/1300_4.jpg

Cant you change the post processing settings? There are things like 'Muted' and 'Vivid' in the options screen.

[Slainchild]

Cant you change the post processing settings? There are things like 'Muted' and 'Vivid' in the options screen.

The main post process settings are controlled in the map itself, so the mapper has to go and set that up per map. The distance at which DOF starts, how much it blurs, Colour Levels, Bloom Intensity, etc cannot be changed any other way (afaik).

[TossMonkey]

You have some control over bloom intensity in the configuration files.

[shadow_dragon]

Yeah but the human eye is a fair bit different to a camera lens for eg. Infact if I look at a globe the little dot gets stuck in my vision afterwards because of the way our eyes adjust to light variations. It certainly does get blurry around the edge of a light source, which is where bloom does work but Ive been outside in very hot sun living in the desert and not very many surfaces at all completely white out under intense sunlight.

See the lightsource bit is kewl its what it does to the rest of the screen at the same time, they do it alot in soapies like days of our lives or somethin where everything emits a halo effect for drama. Not only that but they do high contrast in that one, I think twin peaks did it as well without the contrast.

Things Im talking about is like lens flares, corona's do happen under the right atmospheric conditions. I think thats something they should take into account more, volumetric lights can be blurry but they can add to the atmosphere when used correctly.

You should consider that your, kinda of not really looking at the action in an FPS through your eyes but more through a monitor via your eyes. Essentially rendering everything 2D.

I believe many game designers lean away from trying to reporduce a natural eye type perspective of FPS games these days, hence why it's only the bare minimum these days that you can see your feet/cleavage* when you look down.

For a while now game designers have reproduced camera lens style effects to render more realism to FPS games, with things like lens flare and such. I think bloom is a genuinely good tool for games it's just poorly used in some cases... though i make exceptions to when the unrealistic-use actual improves the visual aesthetics.

I think in the future when designers have gotten the swing of it and it's been coupled with eevn more advanced tech it'll prove to be a useful enough tool.

* I recall some game from a decade or so back with dinosaurs on some tropical island and to check your health you had to look at a tattoo of a heart on the top of the female character's.... chest, that you had to play as. I recall you could shoot yourself in tthe foot, but not the boob thankfully... they really would've gotten in the way I fear.

[MonsOlympus]

Trespasser is the one ;)

[GeckoYamori]

It seems like almost every new visual gimmick in games are used by developers like a kid discovering the lens flare for the first time in Photoshop. Looks like we are at least finally distancing ourselves from having everything look like it was covered in buckets of grease using normal-mapping.

[Jacks:SmirkingRevenge]

Even if the surface has details in it which would be like a shadow, ofcoarse white materials emit some light which will bounce off other nearby surfaces but this gives the impression its glowing which a matte material wouldnt do.

Yeah that shotgun looks untextured from here as well :p

Keep in mind in that shot it's a low sun coming in hard from the left. Maybe your display is bright? It isn't really killing any of the details or the surface texture. You can still see little rocks on the ground and the stretch of wearing material continuing down the wall on the right.

Oh, and smooth stainless steel shotguns tend to not have much texture ;)
What did you expect it to be brown and black and shiny and brand new?

[MonsOlympus]

It looks matte grey from the shot, maybe it is just black in direct sunlight. I mean the shot itself doesnt look bad but I do feel alittle detail is lost in the whiteout, you can certainly see alittle bit of rocks but not much. I mean it just looks wierd to have shadows there at all with all that white on the ground and in the shadows you can see the amount of detail that is being lost from bloom. You would certainly expect some highlights on the top of the rocks but since its just a texture it all comes out flat.

I guess its just a style they went for but I wouldnt call it 'realistic' TM :lol:

I dont think my display is bright, even if it wasnt Id just end up with flat grey spots instead of flat white spots theres an obvious lack of details in the fully lit areas. Specular highlights and bounced lighting is one thing, this bloom is something else entirely :cool:

[DarQraven]

The way I understand it, bloom is used because of the limited brightness of computer monitors.

The problem is that monitors only have 255^3 colors, which means 255 brightness levels. The actual brightness depends on the brightness level of the particular monitor, but in short this means that there are only 255 steps between pure black and pure white.

In real life, there are WAY more steps, probably infinite. However, until someone develops a monitor that can match the light intensity of say, the sun or a magnesium flame (both pretty bright), accurate light reproduction is impossible.

What bloom does is compensate for brightness levels that are outside the monitor's range by simulating what your eye would see if the monitor actually could make bright enough images, and somehow adding that to the normal image (in 255^3 colors of course).

HDR is more or less the same principle. It processes the lighting in a much wider range than the monitor is capable of displaying or the eye is capable of seeing at the same time, and then uses that data as well as the average image brightness to compress that data into an image that monitors can display.

This has little to do with camera lens effects. More with the sensors. When we're talking about lens flares, yes those are lens effects.

[Plumb_Drumb]

the sun or a magnesium flame (both pretty bright)

haha! I found that pretty funny.

You can see instances of bloom on any clear sunny day.
It doesn't require a camera lens or some stuff.

[Adelheid]

I love it when threads go in directions like this, you learn so much :D