SSAO Demo

Hi,
after developing my Wavefield demo for the shader contest, I tried something new and started writing a GS SSAO implementation. The technique is very similar to the one described in the Starcraft2 paper.
Here are some screenshots (2x with+without+ssao_mask):







http://img527.imageshack.us/gal.php?g=ssao1with.png

It´s still not perfect as I downsample the depthmap for a around 10fps performance boost, but get artifacts depending on the lost of information.
The shown screens run with about 80-100fps here...

Some feedback would be cool

regards,
Hummel

PS: Winning a Prof version from the contest could motivate me to upload the Demo+sourcecode^^

looks like you are already winning a Pro edition, afaik 2 pro editions awareded this time. as first and second prize.

would love get my hands on that.

i second that

I'm still thinking that SSAO is one of the most useless shader... All I can see is that with ssao, objects have a dark glow.

I know SSAO should give the scene more depth, but I simply can't see any difference?!
Or am I overlooking something?

(@Hummel: Please don't see this as negativ criticsm of your work!)

Oh-I forgot to mention that it is a small level with some newton-physics
I decided to use a physic-level to get an extremly dynamic scene.

Thx for the comments!

@dark_samurai: normaly SSAO shouldn´t give a dark glow as long as an oject is f.e. not directly in front of a wall.
The SSAO term (should) decribe/s wich parts of the scene were generally reached by less light.
Imo the quality difference is quite big-f.e. it gives the player more information about the distance between objects.

I don't know what is meant with depth, but ambient occlusion adds shadow where we normally expect shadow, mainly where edges and objects touch each other.
When you look at the pic above 'without SSAO', there are no shadows or darkness between and under the objects, and that looks as if the objects fly or have unnatural lights attached.

SSAO is what bump mapping was a few years ago... It was the latest technolegy, which many considered to be to slow to be used in realtime, when it was used in Crysis and now it is on its best way to get a standart. Interesting is only going to be which way of doing it is going to be the most popular one.
In my opinion, it can help to add a lot of additional depth and atmosphere into a scene and is just an awsome technique

I am amazed by Hummels results, although there is of course still a lot of space for improvements

I don't really like SSAO myself, mostly because I have A6 and I can't use it, haha.

But to help you see the difference. SSAO gives objects shading and shadows like on an overcast day. You have no real shadows, but when something is near another surface you can see a extremely blurry shadow, more of a dark blob.

I know that is not what SSAO does, but to the "amateur" (no offense) that's the easiest way to comprehend it.

As for the screens: Nice, what GPU do you have? 80-100 fps on 1680x1050?

I have read that some graphic cards will do AO automatically if you switch this on in their driver. So it might be that such custom shader AO effects will become redundant in the future.

This doesn't look half bad
There is still much room for improvement of course (you know that yourself i guess ), but efficient ssao really is a b1tch to create.

We should exchange ssao shaders sometime, mix them up and maybe finally create a working one for the sake of pushing A7 ?

Anyway, good work and keep it up!

I really don´t think so. It could be a nice feature to improve the look of old games, but it would just be lacking control. And the information needed for it are anyways already there in a modern engine, thus it would most probably do things two times that way. What could make sense and most probably will happen that as always AMD/ATI and NVIDIA (and Intel) will each develope there own feature to help developing it and speeding it up. I never got the NVIDIA shadow mapping thingy to work somehow...

@Michael_Schwarz: it´s a nVidia 285GTX btw. the explaination with the overcast day is always a good one for (SS)AO

@BoH_Havoc: why not, we are all interested in getting fast, good-looking, easy-to-use (and -understand) shaders, but my current motivation for SSAO is nearly zero and I still have to clean up my code
Give me some days to motivate myself, while doing something else - I´ll write you a PM in the next time

@Hummel
No need to rush. Just let me know as soon as you want to touch ssao again

@Machinery_Frank: There is indeed an option in the nvidia drivers to turn on ssao for "every" game. But it's DX10 only and as far as i know it doesn't work that good. Haven't tested it myself though.

Great job Hummel
Get your motivation back! ^^

soo.. enuf days to motivate yourself yet?

any progress on this?

it looks like done in unreal engine men!

Hi Hummel,

any progress with the SSAO Shader?
Maybe you can post some more screens.

This shader really adds to the visuals of an outdoor scene.

I didn´t work on this shader since writing this post but I already thought about working on this stuff again (yesterday) what would make sense because my skills increased and so I could optimize the effect in speed and quality.
BUT at next I´m going to write my first paper wich will be about the spherical light sources. I found only one paper about spherical and cylindrical lights and that one is not free to get -> chance for me

The SSAO Shader would be a nice contribution for
development. It solves quite a lot of troubles in
making a scene look better eluminated, when using a pure model based scene.

So if you find the time, would be great if you can continue an that.

but as I mentioned in the Ancient Gems Thread: a rendering pipeline cant be implemented in a gerneral way, f.i. SSAO requires a deferred shading pipeline wich means you have to do lighting with pp-effects too or your shaders have to output the required data at least. I can´t implement a simple function you just need to call to toggle SSAO on.