What does Post-processing means and how can it helps?

[MasterGod]

1. What is Post-processing?
2. How can it helps (does it?) in games?

[white tiger]

post processing effects mean to process the final already rendered image instead of change the way the scene will be rendered by substituting your gpu programs (shaders) to the ones in the fixed pipeline

in other words the scene will be rendered "normally", then you process the final result. for an example search for bloom (or glow)

[MasterGod]

Ohh...
Cool.
Thanks.

[jingquan]

It helps in improving your scene's realism, mostly by simulating the properties of an actual camera lenses like depth-of-field, bloom, dynamic range and color/brightness toning.

Postprocessing is widly used in games nowadays, especially bloom, which is probably overused? I had that overly blurred and exposed problem last time but solved it with HDR. You should check that out too.

[MasterGod]

So Post-Processing is done with shaders?

[Dorth]

not automatically, but you'd be hard pressed to do it with anything else with anything near a decent framerate...

[JP]

What you do with post processing is render the scene into a texture and then pass that texture to a shader to do some funky effects, as people have already mentioned.

If you don't know shaders then you could also just mess around with the texture yourself within your code, rather than passing it to a shader and could do things like blurring and probably any number of other things (though possibly not all the things that shaders are capable of..?) but as people have mentioned it wouldn't be as quick as shaders so your framerate would probably suffer a fair bit.

But i would just suggest that you learn how to do shaders (if you don't know already), they seems quite confusing and hard when you don't understand them but they're not actually all that complicated if you put in some time to understand what's going on.

[MasterGod]

Ok I understand now why is it called POST processing and what is it.

@JP: I don't know shaders yet but I want to learn later on when I get some free time..

Thanks guys.

[fmx]

whilst we're on the subject of POST-Processing effects, and WHY they're used...

jingquan, you mentioned you used HDR to "fix" your issues with blurred problems with "shaders" (I'm assuming);
could you possibly elaborate? Did you achieve it with Irrlicht?

I'm familiar with shaders, but I'd be interested to hear (as probably would others) how and where HDR can come into play to help with successfully achieving Post-Processing effects (particularly in relation to Irrlicht)

[oldskoolPunk]

Post means after.

[jingquan]

whilst we're on the subject of POST-Processing effects, and WHY they're used...

jingquan, you mentioned you used HDR to "fix" your issues with blurred problems with "shaders" (I'm assuming);
could you possibly elaborate? Did you achieve it with Irrlicht?

I'm familiar with shaders, but I'd be interested to hear (as probably would others) how and where HDR can come into play to help with successfully achieving Post-Processing effects (particularly in relation to Irrlicht)

Yep, I managed to inplement HDR in my engine (using IrrlichtCP), except the luminance adaption problem, which I'm not sure how to store textures from another frame.

I use a brightpass filter to cut off the dark areas, leaving only those bright areas bloomed. Then interpolate this result with the original. This definitely solved my blurry problem.

Of course, I tonemapped and tested for average luminance for HDR.

[Virion]

The most stupid post-processing i've seen so far is the grayscale screen. That can be achieved so easily by just converting every texture into grayscale mode.

[jingquan]

Actually greyscale textures could be quite useful if not rendered on it's own. The most simplest, working, postprocessing is invert i think : 1-color

[Virion]

Actually greyscale textures could be quite useful if not rendered on it's own.

That is useful when you need to switch dynamically from colour mode to greyscale mode; forth and back.