Possible car "Jaggies" Explanation

  • Thread starter DARCwizard
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If this has somehow been mention or discussed then I am sorry for the double thread (I searched and found nothing).

So, we have all seen that the cars at certain angles can have some pretty bad "jaggies" on certain parts. For me its where doors meet and the roof. Specifically in the showroom. And while I am not complaining about the graphics because they are STILL rediculous, I have noticed something. In races, often the cars DO look smoot, and the next moment, they are jaggie...

I think that the jaggies (in the race not in the showroom) are acutally form a reflection map or somthing like that. When a car goes by and the light source is behind the car (as in the car is between you and the light source) I can see a ton of jaggies, and they are usually white or yellow. When you are on the "bright" (you are between the light source and the car) side of the car, there are less to close-to-none jaggies... Maybe the cars have higher AA turned on then reflection maps or light maps or somthing to that effect if you catch my drift. As for the showroom, your guess is as good as mine. However in the race, I am convinced that the cars themselves have AA turned on because for half the race the lines look perfect, and when there are jaggies, they are bright, almost as they are reflecting....

Any thoughts? AGAIN, I am not bashing, simply trying to get an explaination.
 
7,846
GTP_Royalton
It is interesting that the white crawl in the oulines of the car, the jaggies as you call it, is always bright.

The problem use to be real bad when the demo was first released, as it distracted from the graphics quite a bit. However, PD has updated the game and reduced this white crawl. Notice that when you launch the demo at times you look at a black screen for 5-10 seconds before it loads? I think that's when the downloads happens.

Does this crawl have something to do with reflections? Maybe, you do offer a decent explanation, but the idea PD reduced it with a rather small update tells me it probably won't exist in GT5:P or GT5. Personally I hope PD rids this problem completley, because it always tends to attract the eye though being quite insignificant on the grand scale
 
The showroom and the garage show jaggies because there's no antialiasing whatsoever happening in those shots. They are, however, rendered at full 1920x1080.

You're close in the explanation of the in-game jaggies. In-game is rendered at 1280x1080, with 2X multisample antialiasing (MSAA). This form of AA essentially draws the edges twice and then blends them together to reduce the aliased edges (what we call "jaggies"). For example, an edge that's 75% brightness (background) and 25% brightness (dark-painted car), is averaged out to create a 50% intermediate.. so it blends from 25-50-75.

The problem comes from the HDR lighting and reflections. Their values are significantly higher than the old limit of 100. So, let's take your example about chrome bits and their reflections. The car we'll leave at 25% brightness, but the reflection is now 300% brightness. The average value for that is over 160%. LDR displays like TVs and computer monitors can't display that as an intermediate level, so it remains blown out to pure white. This results in a sharp, jaggy edge in spite of the attempted AA done by the graphics engine.

This is something I've run into many times working HDR imagery in LightWave. Even at 33X MSAA, there's still a jagged aliased line where there's a super-contrasted edge of very-dark vs very-bright. The only way around it is to reduce the HDR levels via tone mapping prior to antialiasing, or by using FSAA, rendering the image larger than the display resolution and then shrinking it down. Needless to say, with a game that's already struggling to hit 1080p, that option simply isn't available.

Whether they'll be able to work around it or not is yet to be seen. Even so, jaggies at 1080p are very small, and don't do much to hurt the overall image quality.
 
342
tofuman
interesting, for me i experience the most jaggies in the shadows and some minor ones on the car models. But to answer your question I think PD hasn't fully optimized the game and we should see some visual improvements on the full release ver. of GT5P.
 
Interesting information Earth and Jedi. I didnt know the game was updated however, I felt like I have seen a little less the past few times I have played the game. On a grand scale, It does not keep me from enjoying the game one bit at all. I just though it was wierd that the "jaggies" were coming from the reflection and not the car itself. Jedi2016 that was a perfect explaination! I definitly agree that they will have to work something else out besides FSAA, because you are right, unless they do a lot of work to make the engine run more efficient (which I am most certain they will considereing they probably haven't really even reached that stage in their development cycle yet) it is going to be tough to get it smooth on an even higher render resolution.
 

kikie

I'm here
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Belgium
in the land of stupidity
Jaggies are almost gone. PD must have updated the demo on everybodies HDD.