SSAA
("Screen Space AntiAliasing")
Supporting AnitAliasing has become a serious problem for game-developers in the last years. Most of them use some kind of Deferred Rendering now, which does not support Hardware-AntiAliasing. But since everyone likes to have antialiased scenes in games anywas, developers have to come up with some little tricks.
For [w]tech we're using a post-processing effect which we call simply "Screen Space AntiAliasing":
This effect is very low-costly, and we’re quite happy with the results. Though, it looks best on round things.
HBAO
("Horizon Based Ambient Occlusion")
Another new PostProcessing-Effect in [w]tech is “Horizon Based Ambient Occlusion”, which was originally invented by Nvidia.The results are very pleasing for a screenspace approach of AmbientOcclusion. Of course those will never be as accurate as the non-screenspace versions, but those can’t be handled pretty well in realtime on current hardware.
Here are some pictures of the HBAO-Effect, rendered at a resolution of 800x600 on ATI Radeon 4890:
A little animation which should give you an impression how HBAO can improve the illusion of reality:
As SSAOs always are, this effect isn’t lightweight. Luckily a drop from 300 to 140 FPS isn't that bad, since FPS are non-linear. A drop from 30 to 20 would be much worse!
For more information, visit: www.wtechportal.com
![[w]tech](https://media.moddb.com/cache/images/engines/1/1/146/crop_120x90/Preview_moddb.jpg)
![[w]tech team](https://media.moddb.com/cache/images/groups/1/1/997/crop_120x90/wtechteam_preview.jpg)
Ambient Occlusion is on the best atmospheric effects out there. It creates wonders if you ask me. Pity it's such a costly effect.
I have always been a fan of ambient occlusion rendering but i feel it's always a big performance hit and generally i always turn it off as you get 20 fps+ most of time.
That's why there are high-end graphics cards on the market ;) Of course I udnerstand that not everyone can or wants to spend that much money on a graphics card. But yeah, AO is great, I love how it generally adds a lot to scenes.
I'm not sure what it does besides adding blobbish shadow effects where two surfaces are at close proximity to each other. While in some situations it makes the image look more realistic, in other situations it creates excessive darkness where darkness doesn't belong.
It adds shadows on edges of everything. It gives the scene more definition which generally makes it look better, it can sometimes back fire though and then everything looks dark and blurry.
That's what AmbientOcclusion is supposed to do. It simulates the light coming from the sky, which comes from almost all sides in the world.
Imagine you see some car on the street. There will be a very soft shadow underneath it because it blocks the light from the sky. Just using a shadow-casting light won't do the trick to get that shadow. It would be too hard and would feel unrealistic.
Sure, no screen-space approach can get even close to the real ambient occlusion, but current hardware isn't really capable to compute that in realtime (Well, it works, but it isn't really fast). So you're right, it will create shadows where a shadow doesn't belong to sometimes. One of the problems you have with SSAO.
Amazing.