Shadows in GT5

[Captain Roh]

Ok so I'm aware that this subject has been done to death all over the forum, but I dont think I ever really understood the whys and hows.

Basically no one can deny that the shadows within GT5 are somewhat of a let down compared to the visual prowess of everything around them. That said, I personally dont care enough to let it get me down. I'm not here to discuss wether they should be sorted out thats for sure.

On with the debate anyway.... I just finished watching one of the videos on the news blog which i'll post below. You can most clearly see the effect I'm talking about on the skirts of the enzo. What is this? I'm not fully clued up as to how dynamic lighting effects actually apply themselves to textures and polygons and what not. What causes the jagged effect?

You can also see a flickering near the end of the video, although the car is not actually moving. Is this caused by the light source or the rendering of the car? Or neither? Like I say I'm pretty clueless.

I'm also interested to know how, or if the 'problem' could be reseolved. Maybe there just arent enough resources left in the PS3's arsenal after displaying a 1080p picture at 60fps. But how in theory would realistic dynamic shadow effects be applied to GT5 as it is now? Better hardware? A compromise in visual quality? Possibly something simple like the banishment of a HUD completely? Pre loading? ... I just dont know.

Thanks to anyone who can shed some light. Here's the video for reference, although I'm sure you know what I'm talking about

 

[wakas]

Absolutely hate those broken - low res shadows. Its a hardware constraint, not enough juice in the current generation consoles to produce high resolution shadows, it does not mean that they can't, the performance hit is just too big. The HDR lighting just exaggerate the effect as it increases the contrast in a way.

 

[daan]

Thanks to anyone who can shed some light.

Well done.

I'd like some answers too as I'm in the dark on this subject.


I think we both need our coats...

 

[LaBounti]

Absolutely hate those broken - low res shadows. Its a hardware constraint, not enough juice in the current generation consoles to produce high resolution shadows, it does not mean that they can't, the performance hit is just too big. The HDR lighting just exaggerate the effect as it increases the contrast in a way.

Shadow detail is memory dependent, not CPU or GPU power. The 256MB of Video ram is already getting hammered with 1080p and reserves for weather effects, skid marks etc... Flat ground shadows are different in most cases as they can be just dark colored polygons.

On a side note I'm not bothered by shadow detail in the slightest.

 

[PrimalOrB]

the models are normal mapped models also, meaning they model a high res model, and then transfer the normals (shading/surface information) onto a lower resoultion model.

the result being that a model looks like its extremely high-res, but is still just the lower res model and takes less effort to render

this alone can be part of the problem with the shadows, but as with many, I could care less about the shadows, just want the damn game!

 

[NINE_HUNDRED]

Well done.

I'd like some answers too as I'm in the dark on this subject.


I think we both need our coats...

Not really got much input to this but me personally, when I'm driving round a track I'm not going to be thinking "those shadows are putting me off" or whatever, I'll be more interested in actually driving the car. But that's just me.

 

[LaBounti]

the models are normal mapped models also, meaning they model a high res model, and then transfer the normals (shading/surface information) onto a lower resoultion model.

the result being that a model looks like its extremely high-res, but is still just the lower res model and takes less effort to render

Thats not the case as the car still as a reflection "map" thats higher res than the shadow "map", A normal map is a shader program, Polygons can have multiple shaders, each shader can be any resolution. Texture maps are different resolutions than shadow maps, thats how you can get NASCARs with logos that arent super blocky like the shadow map. its all dependent on the video memory to handle the maps. Polygons do not have a limit on the number of pixels that are mapped to them, even if its just 2 polygons. Its the video memory and the number of shaders used that determines that limit.

 

[Falango]

Dynamic shadows are very intensive, so having high detail shadows rendered realtime is hard to do, especially in this case where Kaz wants 60fps all the time. I saw these jagged shadows in this video too, and was pretty disappointed, yet the shadows we see on the interior of the cars seem alot nicer. I'm tryig to wrap my head around this. My assumption is it is a surface shading issue on the cars.

Thats not the case as the car still as a reflection "map" thats higher res than the shadow "map", A normal map is a shader program, Polygons can have multiple shaders, each shader can be any resolution. Texture maps are different resolutions than shadow maps, thats how you can get NASCARs with logos that arent super blocky like the shadow map. its all dependent on the video memory to handle the maps. Polygons do not have a limit on the number of pixels that are mapped to them, even if its just 2 polygons. Its the video memory and the number of shaders used that determines that limit.

That's true. Maybe they have had to limit the shadow maps to a much lower res. But again, this isn't the final build, so hopefully we will see a higher res shadow map in the end.

 

[Talyn]

Well hopefully the shadows have been improved in the final build but I also believe the low resolution youtube videos make the low quality shadows more obvious.

 

[m00ndancer]

I really don't think that the shadows will be that much better in the final build. They are more than ok in my book now. The reason I think so is that I did some testing a few months ago with rFactor (yes, I know it's a PC game and not on the same platform).
In rFactor you have a setting that's called smooth shadows (If I remember correctly) and on my old card (ATI1950Pro 256MB) the game almost died when enabled it and the memory requirements went up the roof. I did the same test on my twice as fast GFXcard (ATI 4850 512MB) and there is a hit but not nearly the same, but the memory requirement is still there. So my conclusion is that I think the PS3 is on a memory limit here. Might even be so that GT5 will have better shadows in 720P than in 1080P.

Just my 0.2 cents

 

[KopparbergDave]

Sadly it'll be a while away yet, but imagine GT7 (or maybe 6, you never know) running on the PlayStation 4. Gran Turismo only really has a few areas, graphically, like the shadows, that really need improving upon. The weather effects look bloody awesome for their first attempt, and with the huge increase in horse power and advanced graphical effects in the next PlayStation, I can actually imagine real, photo-realistic, utterly believable graphics, and on top of that will be scale. All that glory, but with 30 cars on track, solid 60fps, physics that basically reflect reality spot on, and.. some day at least, every peice of a car actually modelled, graphically, and in the physics, car's that can literally break apart, bit by bit...

Gotta dream.

As for shadows, they're a tiny bit distracting when they don't look too good in the cockpit views (and the cockpit views shadows seem to vary from good to bad for some reason), but seriously, this game will look amazing, remember just how good it looks in relation to EVERYTHING else, and how solid those graphics are, compared to any other game, even Codemaster's games which are a bit heavy with post-processing that makes everything look too glossy and Hollywood. Gran Turismo is the most realistic looking game I know at certain moments in replays. Mmmmmm, fingers crossed December at the latest!

 

[cygnus_zero]

Ive read on many sites that this is due to dev's relying on the PS3s relatively weak GPU to render the shadows, which is why so many PS3 games have those jittery looking shadows.

The 360 does in fact have a stronger GPU, which is why I dont think ive ever played a 360 game with shadows like ive seen on the 360.

There was an article on cnet about this, and it used Uncharted 2 as an example of how to develop games for the PS3. It mentioned something about a different way to develop where you rely more on the CPU to handle this stuff rather than the GPU, but I guess its pretty complicated. They also talk about this in the uncharted 2 behind the scenes vids, talking about a new way to make games that makes more use of the cell processor. Apparently PD doesnt know how to do it.

 

[Owen.C93]

Ive read on many sites that this is due to dev's relying on the PS3s relatively weak GPU to render the shadows, which is why so many PS3 games have those jittery looking shadows.

The 360 does in fact have a stronger GPU, which is why I dont think ive ever played a 360 game with shadows like ive seen on the 360.

There was an article on cnet about this, and it used Uncharted 2 as an example of how to develop games for the PS3. It mentioned something about a different way to develop where you rely more on the CPU to handle this stuff rather than the GPU, but I guess its pretty complicated. They also talk about this in the uncharted 2 behind the scenes vids, talking about a new way to make games that makes more use of the cell processor. Apparently PD doesnt know how to do it.

No, just the shadows on some cars in the demos weren't completed yet.

 

[Khaddar]

They also talk about this in the uncharted 2 behind the scenes vids, talking about a new way to make games that makes more use of the cell processor. Apparently PD doesnt know how to do it.

Uncharted 2 is very pretty, but it's relatively a pretty simple game. GT5, and racing games in general, is doing a lot of calculation that has nothing whatsoever to do with graphics. I think it's likely that shadows are not a priority use of PS3 processing capabilities.

 

[5Liter]

The shadows were a huge let-down in the demo...they looked horrible actually. Very out of place because the rest of the game looks great. Other racing games manage to have nice shadows...hell, even SHIFT has better shadows than this game.

 

[Spagetti69]

Hope this isn't the reason we don't seem to be getting a decent hood cam.

Think about it. With a proper hood view, shadows from trees etc would be in your face.
Putting the cam on the roof, draws away the effect somewhat.

If you understand what I'm getting at.

 

[Stonemonkey]

Shadowmaps are rendered before the actual frame is rendered from the lightsource point of view into what is basically a texture that stores depth instead of colour information. That shadowmap is applied when doing the final render and a comparison is used to determine if a pixel is in light or shade, the shadowmap isn't really drawn onto the car or surface.
Rendering the shadowmaps takes time, the larger (higher res) the shadowmap, the longer it takes, and also takes up more memory. I'm not totally sure about the PS3 but most graphics hardware (this applies to software rendering too which might be the case if the cell is involved) prefer to have their texture dimensions as powers of two so each step up in size results in 4X the number of texels in the shadowmap and 4X the memory usage.

 

[LaBounti]

Ive read on many sites that this is due to dev's relying on the PS3s relatively weak GPU to render the shadows, which is why so many PS3 games have those jittery looking shadows.

I thought corrected you before about this, did you not even read my post? This post is so far from accurate. The PS3's gpu is weak compared to new gpus but its not the reason a specific game has low res shadow maps. Its the video memory. Self shadowing is very taxing on any gpu. To do it with real time lighting is even harder on the system that has to keep 1080p60.

The NV70(RSX) is very capable of high resolution shadows. Maybe you have never played a PC game that had a high resolution shadows option. With that option almost always do they warn you about the option requires a lot of memory. Bottom line is shadows are memory limited not gpu or cpu.

 

[Griffith500]

Using the CPU to do graphics tasks isn't anything new at all. What is new, is the architecture involved on the PS3, namely: the SPUs. That's the complication. I'm fairly certain that PD can master the ins and outs of that architecture, given they are a first party developer.

It's clearly an optimisation issue, and it is almost entirely because of the dynamic lighting system. The shadows need to be recalculated not only for the cars, but all the scenery, too, in order to keep astride of the changes in lighting. Assassin's Creed delays the update every few frames, so that the shadows visibly march, stepwise, across the scenery - a compromise.

Here, it seems, the compromise is in resolution.

EDIT: here's a nice article on the subject, but the application is very different requiring shadows cast over very large distances and requiring small scale detail at the same time. But it does go over a few techniques and their relative merits and drawbacks, as well as touch on the technical requirements.

EDIT: no idea if that link is working... here's the month it came from, it's under "shadowing part ii" (fourth entry) and is concluded in this post. It's all a bit heavy going, actually.

 

[B13POS]

I think they look fine. 👍. This isn't shadow simulator 2010.

 

[terminator363]

I think they look fine. 👍. This isn't shadow simulator 2010.

I hate it when people say things like this, everybody knows this game will be great, we aren't arguing why it sucks or anything, we are trying to improve it by giving our opinions and thoughts, I don't understand why you and others are taking this as if you think this game is just about cars and only about cars. There is a lot more to a game than you think. It's what gives you that sense of realism, and envelopes you as a driver in game.

Edit: Wow I just realized how much thought I just put into that.

 

[B13POS]

I hate it when people say things like this, everybody knows this game will be great, we aren't arguing why it sucks or anything, we are trying to improve it by giving our opinions and thoughts, I don't understand why you and others are taking this as if you think this game is just about cars and only about cars. There is a lot more to a game than you think. It's what gives you that sense of realism, and envelopes you as a driver in game.

Edit: Wow I just realized how much thought I just put into that.

Implying I am upset in general and that I think it's only about cars. It's a video game. Not everything is going to look amazing. Considering they're trying to keep the 60FPS.

 

[terminator363]

Implying I am upset in general and that I think it's only about cars. It's a video game. Not everything is going to look amazing. Considering they're trying to keep the 60FPS.

As I said before, everyone always looks at improving things and making them better and better. Not everything will look amazing, but there is always space for improvement, in GT5/after GT5.

 

[Beat the Beat]

It's clearly an optimisation issue, and it is almost entirely because of the dynamic lighting system. The shadows need to be recalculated not only for the cars, but all the scenery, too, in order to keep astride of the changes in lighting. Assassin's Creed delays the update every few frames, so that the shadows visibly march, stepwise, across the scenery - a compromise.

I may be wrong but I've not noticed any dynamic environment shadows on the Toscana track, the car shadows get longer but the trees don't. I'm expecting simple slow fades between lighting conditions for the most part.

 

[ChUnKieBaLLz]

Don't know if anyone mentioned it already, but I always felt the cars looked like they are floating on the track when they are not in direct sunlight. I don't really know how to explain this properly, but whenever the car drive underneath a building and the sunlight is blocked off, the car instantly feels like it's disconnected from the ground. Since a picture is worth a thousand words, I've put in some GT5 vs. Real life pics for reference.

Now I know this can be argued differently because of the angles or because they are pictures and not videos, but in GT5 photos, doesn't it feel like the shadows under front bumper and side skirt are a bit lacking? Or at least not enough of shadow generally under the car? When I look at the bottom of the front bumper in the 2nd pic, it just doesn't feel right. Oh well...maybe it's just me. Feel free to disagree.

 

[cygnus_zero]

I thought corrected you before about this, did you not even read my post? This post is so far from accurate. The PS3's gpu is weak compared to new gpus but its not the reason a specific game has low res shadow maps. Its the video memory. Self shadowing is very taxing on any gpu. To do it with real time lighting is even harder on the system that has to keep 1080p60.

The NV70(RSX) is very capable of high resolution shadows. Maybe you have never played a PC game that had a high resolution shadows option. With that option almost always do they warn you about the option requires a lot of memory. Bottom line is shadows are memory limited not gpu or cpu.

The PS3s GPU is weak not just compared to modern GPUs, but if you compare the specs with the 360s GPU, its weaker in almost every area, primarily the RAM, with the 360s board has twice as much of, and came out a year earlier.

My point is that this game is suffering in some areas due to limitations of the PS3, and if you watch the behind the scenes vids that come with Uncharted 2 Naughty Dog explains this exact issue.

Im pretty sure Forza 3 is doing a lot of calculations as well. To wait 4+ years for a game to end up getting shadows that look like PS1 quality is irritating, and I wont start making excuses for it to make myself feel better about it. It is what it is, it looks like crap. Doesnt really matter why they do, they just do.

 

[Gejost]

Don't know if anyone mentioned it already, but I always felt the cars looked like they are floating on the track when they are not in direct sunlight. I don't really know how to explain this properly, but whenever the car drive underneath a building and the sunlight is blocked off, the car instantly feels like it's disconnected from the ground. Since a picture is worth a thousand words, I've put in some GT5 vs. Real life pics for reference.

...

Now I know this can be argued differently because of the angles or because they are pictures and not videos, but in GT5 photos, doesn't it feel like the shadows under front bumper and side skirt are a bit lacking? Or at least not enough of shadow generally under the car? When I look at the bottom of the front bumper in the 2nd pic, it just doesn't feel right. Oh well...maybe it's just me. Feel free to disagree.

I'm playing League of Legends lately, unfortunatly on a low end PC. In order to get a decent framerate, I tried many things, including turning shadows off. It seemed like the characters were disconnected from the ground, like they were floating. Same here with those pics, I definitely agree. I learned that shadows are very important.

 

[5Liter]

Its not just the shadows on the cars that look bad...look at the shadow from the fence onto the car...looks TERRIBLE and it would look better without any shadow honestly.

 

[Dravonic]

The PS3s GPU is weak not just compared to modern GPUs, but if you compare the specs with the 360s GPU, its weaker in almost every area, primarily the RAM, with the 360s board has twice as much of, and came out a year earlier.

It's actually a lot more complicated than that really.

Both video games have 512MB of memory but the PS3's memory is equally divided between the CPU and the GPU while the 360's has a single memory bank. The PS3 has 256MB of memory dedicated to the CPU and 256MB of memory for the GPU while the 360 has 512MB for both. There are certain advantages for having split memory banks but on the other hand you have pre-determined amounts of memory to deal with, while the 360 allow developers to choose how they will use their 512MB of memory, splitting it between the CPU and GPU as they see fit. The PS3 actually has a turbo cache feature allowing the GPU to use some of the CPU memory as a fast cache, but that doesn't work well really and I don't think developers actually bother using this feature.

Anyway, LaBounti is only partially right. Shadows are indeed limited by memory but they are also limited by GPU processing power since the GPU has to render the shadow maps. The higher the resolution, the less jagged they will look, but the more processing power you'll need to render them and the more memory you'll need to store them.

In GT5's case it's already mind-blowing how has PD managed to make the game look this good. The GPU's memory and processing capabilities are most likely already maxed out so if you try to add higher resolution shadow maps to the equation, well the game won't run in 60FPS anymore.

TL;DR: The shadows have to look jagged in order for the cars to look like this good.

PS: GT5P has some ridiculously low resolution shadow maps sometimes. I wish PD just dropped these low resolution shadows instead rendering what appears to be 10x10 maps and applying them to the cars, getting some huge artifacts to show up.

 

[trk29]

Don't know if anyone mentioned it already, but I always felt the cars looked like they are floating on the track when they are not in direct sunlight.

Well judging by the pictures you have provided the pictures of the cars in the game do not have a shadow under the body of the car like their real world counterparts. I think that is why the appear to float to you.

Personally I have never thought that way, hopefully I will continue not to notice it.