[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]

 

[Banoffee]

^ Haha

Yeah, it's really nice when used properly.

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. 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

Yeah, it's really nice when used properly.

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. It's turned off where possible here. So lazy.

 

[SleepyHe4d]

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

 

[Slainchild]

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

 

[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.

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

 

[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.

[SCREENSHOT]http://insite.beyondunreal.com/screenshots/1300_4.jpg[/SCREENSHOT]

 

[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

 

[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?