Sign in with
Sign up | Sign in
Your question

What is post-processing?

Last response: in Graphics & Displays
Share
April 17, 2009 3:18:59 PM

Title says it all. Also, what is its use? I'd also like to know how tessellation is going to make GPUs better.

More about : post processing

a b U Graphics card
April 17, 2009 3:28:49 PM

rags_20 said:
Title says it all. Also, what is its use? I'd also like to know how tessellation is going to make GPUs better.


IMO, it tweaks the lighting...basically improves HDR

In Crysis, it creates the light rays if you turn up post processing to very high.




a b U Graphics card
April 18, 2009 2:23:04 AM

i thought you werent serious when you're asking what postpro is from another thread.

post-processing is the sort of "slowmo-blur" effect of the surroundings when you're pitching/yawing your mouse.

try these games:

1. gears of war
2. left4dead
3. crysis
4. moh:airborne
Related resources
April 18, 2009 6:44:47 AM

You mean motion blur? But doesn't Crysis have a separate motion blur option? I've seen motion blur in a lot of games. Didn't realize it was related to post-processing.

Oh and everything around becomes a blur when using iron-sights in Crysis with post-pro to Very High.
a b U Graphics card
April 18, 2009 6:47:59 AM

just move your mouse left to right when playing, turn postpro on and off, you'll see the difference.
April 18, 2009 11:43:30 AM

"slo mo blur" is motion blur not post pross. post pross increases the number of dynamic lights putting more strain on the system and can slow down FPS but makes it look prettier.
April 18, 2009 12:31:52 PM

Here's something I found from another forum:
Quote:
Technically, here's what it is:
(And yay, for once they've actually come up with a descriptive name, as you'll see)

First, you render your game the normal way, except for one thing. Instead of rendering to the screen (after which you can't do anything with it), you render it and save it as a texture.

Then you load up that texture, run a hell of a lot of shaders on that, and render the result to the screen.
Post-processing. Processing done *after* rendering.

The advantage is that you can then work on the final image, whereas in the first pass, you work on each object in isolation. You don't know which background the object is rendered against, what kind of colors are used in the entire scene, the average lighting levels and so on.

All that can be computed as a postprocessing pass. Then you can make bloom lighting (simply find bright areas and smear them out a bit), depth of field or a million other effects. Post-processing is basically just image manipulation, similar to what you can do in photoshop. (edit: Damn, Chaz beat me to that one)

It's also slow, because it requires a second render pass. And obviously, it's 100% GPU-dependant. (more specifically, 100% pixel shader-dependant. Vertex shaders are useless for the second pass, since all you really render is a screen-sized rectangle (4 vertices), with a texture on it)
running a vertex shader on 4 vertices is unlikely to stress any GPU. It's when all the pixel shaders have to be run a second time that the performance hit occurs
April 18, 2009 1:40:59 PM

generally I avoid posting technical documents to this forum as it's disrepectful to the OP. kind of like saying you're a moron who doesn't know how to wiki or google. if he really wanted to know technical specs, I'm sure he would have wiki'd it.
April 18, 2009 2:29:11 PM

I did not find anything in Wikipedia about post-processing in games.
April 18, 2009 2:36:18 PM

bpogdowz said:
generally I avoid posting technical documents to this forum as it's disrepectful to the OP. kind of like saying you're a moron who doesn't know how to wiki or google. if he really wanted to know technical specs, I'm sure he would have wiki'd it.


B+

Yes in some cases your right on the money but sometimes people don't have the patience to actually find a decent article, or they don't have time...etc (some not all, and we're not just talking about this thread).

Ie.

When I'm in the Exam season, work or just plain busy, I want a quick question, I ask the community, and saves me time:) 
a b U Graphics card
April 18, 2009 9:41:16 PM

Well that description could lose the last half (do we have pixel vs vertex processors anymore.. no just assembly stages ad the pixel is after the rasterizer anyways).

AA is another form of post-processing.

An easy way to get a feel for it, all the effects by ATi's Smartshader options (cartoon, ascii-matrix, blur, sketch, stylized B&W, inverse colour, etc.) are examples of post-processing, exaggerated for effect of course.
April 18, 2009 10:01:03 PM

Exactly, like TGGA said, if you notice in games like Assassin's creed I believe they have the AA enabling in the Post Processing:) 
April 19, 2009 12:44:09 AM

Then why does Crysis have separate options for Post-processing, motion blur and AA?
a b U Graphics card
April 19, 2009 1:06:59 AM

^ Well in Oblivion, HDR is related to AA, turning on one disables the other.

So perhaps HDR, Post-processing, and AA are all loosely related to each other.
April 19, 2009 2:28:49 AM

well making AA possible in a different category just gives more option to the user.

Its like going to a restaurant and grabbing the combo, some let you customize rings, fries or vegies in the combo, others don't offer you a combo, they offer you indivdual packs and let you choose 1 thing out of what would be a combo.

Sorry for the crappy analogy, but I'm tired and in between exams.

I would say that in most cases post p can put a heavy strain on the card since it adds the finish on the car. Gives it shine and certain detail to add to the setting.

hope it help:p 

a b U Graphics card
April 20, 2009 5:35:40 AM

rags_20 said:
Then why does Crysis have separate options for Post-processing, motion blur and AA?


Because those SETTINGS control different things as defined by Crytek, doesn't change what post-processing is, only one example of their implementation.

!