The Failure of Soft Shadows and Parallax Mapping

Soft Shadows

We've seen how soft shadows can be used effectively in games like The Chronicles of Riddick, and Monolith has decided to add this as an option in FEAR. Used correctly, soft shadows greatly enhance lighting in a game by giving shadows cast by objects different levels of darkness making them more realistic. This process can take up a lot of processing power however, and that's no exception for FEAR.

Basically, soft shadows are an effect that show how shadows tend to fade at the edges or cast overlapping lines on walls or objects depending on different factors such as light angle and distance. If you've ever made a shadow-puppet, you can see this clearly, as multiple outlines of your hand shadow overlap on the wall with varying degrees of darkness (depending on the light source). And if you were to move your hand closer or farther away from the light, you can see how the soft shadows change dynamically.

The idea is to capture this effect in a game environment, but as any programmer would know, translating this to a game engine can be a very complex undertaking. Not only that, but as we mentioned before, calculating multiple shadows in real time can quickly become a major leech of processing power. With FEAR, we've seen how big of a performance hit that we had when we enabled soft shadows, but you may wonder, "does the effect at least look good?"

The short answer is "no". The way that FEAR incorporates soft shadows ends up looking unrealistic; more stratified and strange than soft. It simply looks as though the game draws multiple shadows at the edges of objects and offsets them up, down, left and right very slightly at different degrees of darkness regardless of the light source. This wouldn't be so bad if the multiple shadows were not readily noticeable as such. It also would have been nice if the "blur factor" were more dynamic; in other words, moving the shadows closer together or farther apart given where the object (say an enemy soldier) is in relation to the light sources and shadowed surfaces.

This is difficult to understand until you see it happening in the game, but you can get a better idea of it by looking at a few pictures. We took some screen shots of a scene with and without soft shadows enabled with both NVIDIA and ATI cards. Please ignore the slight lighting and position differences of these screens.

Seeing the pictures gives you a little better idea of how the soft shadow option looks in FEAR. Since it's not impressive and it gives the game a major performance hit, we don't see any reason to enable it. It might look good with AA enabled, but unfortunately as of right now, both soft shadows and AA can't be enabled at the same time. They might allow this in some later patch, but as we've shown by our performance tests, the cost to performance would be almost too great to think about.

Parallax Mapping

While the detailed textures, excellent lighting, well done static and dynamic shadows (in spite of the soft shadow issue), large intricate particle systems, and various beautiful effects of FEAR come together to form an immersive and fluid graphical experience, there are a few caveats. To their credit, Monolith was very aggressive with the features that they included and are on the leading edge of technology. The use of a deep parallax mapping algorithm to represent damage is a very cool idea, but the implementation used in FEAR doesn't include key features such as self-occlusion and self-shadowing. When passing a wall with a chunk blown out, the hole will swim around, flatten out, and eventually look like unidentifiable goo stuck to the wall as the angle gets very steep.

The parallax mapping used looks great from angles where the entire interior of a hole can be seen. The problem occurs at viewing angles where a near edge would need to block the view of part of (or the entire) interior of the indention. Rather than occluding anything, parts of the texture that should become invisible are still shown (albeit distorted). This completely destroys the illusion of depth at steep angles by making the texture kind of swim until it totally loses its three-dimensionality. There are algorithms available that can represent correctly self-occlusion in parallax mapping. While we can appreciate cheaper parallax mapping algorithms as a kind of upgraded bump mapping, dramatic surface deformation should either be done more correctly or not at all in cases where the viewer can move to angles that break the effect.

But again, we would love to give credit where credit is due. We would rather see game developers experiment with new technology and put something out there than let the true power of our graphics cards remain dormant. Monolith was ahead of the curve with the graphics in Tron 2.0, and they haven't let us down with the quality of FEAR.

The Game/Test setup No Soft Shadows and No AA/AF Performance Tests
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  • eljefeII - Saturday, October 22, 2005 - link

    yeah, x1800 looks like a flop for the most part. and it doesnt exist.
    kinda gay
    Reply
  • ryanlopez4550 - Saturday, October 22, 2005 - link

    but games like this make up for the lower settings

    my friend came over last night and we played online FEAR for 6 hours

    He has a comp i built him with a 6600gt and it ran great on some custom setting and didnt look at all sub par. Didnt lag ONCE all night. The test program in the game is really cool to so now i dont have to sit there with fraps and stuff on for ever

    multi player - the gameplay is so fast most of the time there is NO time for you to admire the scenery
    Reply
  • boyer00 - Saturday, October 22, 2005 - link

    it says how the geforce 7800 is basically the only card to run it at the highest end, i just ordered a alienware about a week ago with, dual geforce 7800GTX-KO's, and a 19"LCD monitor, 4 gig DDR2 ram and 3.2 dual core pentium-D....my question is do i have anything to worry about in the upcoming months/year graphically? Reply
  • Gary Key - Sunday, October 23, 2005 - link

    Since you are probably limited to 1280x1024 on your 19" LCD then you are fairly safe. However, the 840D will have issues in providing enough data (the GPUs will have wait states) for the 7800GTX SLI setup at the higher resolutions such as 1600x1200 in case you decide to change monitors. I have found the 7800GTX SLI setup and the 840EE to run Fear at 1280x1024 (960) without too much of an issue. Reply
  • Regs - Saturday, October 22, 2005 - link

    The answer to this question is always yes. You just bought a excellent system to play today's games. Not tomorrows games. Reply
  • ryanlopez4550 - Friday, October 21, 2005 - link

    i have a 7800 gtx at 490-1300 and a gig of ram and a 3200 amd...

    i tested the game out on the MIN. settings... direct x 7 and such (looked like duke nukem) and i got a max of 60 a min of 58 and an average of 59

    everything else runs HORRIBLY!
    Reply
  • ryanlopez4550 - Friday, October 21, 2005 - link

    ONE MORE TIME

    tried to get the new drivers for my 7800gtx

    its telling me i dont have the right drivers for my hardware... ?????????

    well anywho i uninstalled them all and reinstalled them so i have the old old drivers and now the game runs like normal

    'high' and 'high' settings got me a min. of 54 and a max of 214
    Reply
  • ryanlopez4550 - Friday, October 21, 2005 - link

    ok just tried it again

    max setting (1024x768) soft shadows and 4x16x i got an average of 23 fps

    so i lower the settings... soft shadows off and 2x8x and i get the same results...
    Reply
  • Kung Lau - Friday, October 21, 2005 - link

    Is there any way to get a poll of AT forum viewers and establish which cards get tested on bleeding edge software? Wouldn't that help us see data that pertains to the majority of us. I understand that you can't evaluate every possible card/model/resolution variation but a current reader based poll may help.
    Reply
  • fogeyman - Friday, October 21, 2005 - link

    Post in the forums. Reply

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