Ok. How's it work?

I found the controls in the choreography. I've loaded both a jpg and a hdr image as the environment. I left the settings at their default (well I selected 'Image Based Lighting'), right-clicked and computed the IBL. I rendered. Neat-o. Works pretty fast.

Then I got crazy and tried changing the Ambient Occlusion setting. Bad idea. In my scene (which is just a cube and a camera) the computer just stops. If I do a quick render, when the scanline hits the geometry, it just stops. If I do a final render, the computer gets to a certain percentage and just sits. I let it sit 16 hours, and the percentage never changed. It was not locked up, but it hadn't made any progress.

I believe there is some user error here, so I'm open. What is the right way to use these new settings?

There are no correct way to make it work. It should just work. If you have a project that won't render (freezes or crashes) then submit it to A:M report with the project file.

One thing to note, if you try to do an ambiant occlusion inside a closed box, you will get only black. For situations where you want to use ambiant occlusion inside a skydome, a box, a room, whatever, you can exclude objects from the ambiant occlusion. That's in the object "options" properties.

What exactly is ambient occlusion? Is it a perfect form of skydome or does it also include radiosity calculations?

Ambiant Occlusion does essentially what a skylight rig does, that is soft ambiant shadows except you don't need a skylight rig and it is much quicker to compute.

Sweeet! Is it possible to calculate radiosity using A:M's ambient occlution? And where can i find more about this new feature? The help file for it doesnt exist, so i would have to screw around with settings for an hour if i had no dirrection.

Ambiant occlusion is not radiosity and is not integrated or otherwise related to radiosity in any way. It is just another trick to fake ambiance illumination. It can be used with a global ambiance color or with HDR or LDR environment maps to simulate IBL.

V13 is an alpha release. Meaning it is not actually released yet. Alpha means that features are being developped and added. They are not finalized. Alpha is available for you to test and report the bugs you find. So don't expect help files or tutorials. You are basically on your own when exploring the new features.

Also, never attempt important projects in an alpha version.

The new ambient occlusion is awsome! Nice feature Yves. I especially like the clean look and quick render times. The is an image of some blocks that took 8 minutes and 41 seconds to render at 100% sampling. Just need to figure out how to get IBL to work.

I am having better luck using the global color setting rather than Image Based Lighting and using the Ambience Occlusion setting. I am playing with the settings in the chor and in the render options, but so far so good. I'll have to try that IBL + Ambience Occlusion problem I mentioned a little later.

Does anyone know how to setup and properly render using IBL? I've tried several times and have had no luck in getting it to render anything but black geometry.

On another note, all of my .hdr files are loading into A:M upside down.

Ambient Occlusion solved a problem that I came across many times. I was testing wheather it would leave noticeable shadows because of verticly high geometry. This isn't rendered all the way, because at this point I was certain it was gone.

The reason why the cylinders get brighter towards the top is because I did not create an infinite plane, so the light from underneth the plan is hitting the tops of the cylinders. A nice feature addition would be wheather you wanted a full shere of ambient occlusion, or if you just wanted a dome of ambient occlusion.

where excatly are these setting just cant seem to find them

They're in the choreography properties. Set Global Ambience Type to Global Color, then set Ambience Intensity to 100%, then set Ambience Occlusion to 100% and render. Make sure that you have Ambience Occlusion turned on in the Render Options. You can set the quality of the lighting by increasing the Occlusion Sampling (Maximum 100%).

THIS sounds like another GREAT new feature.

As an animator who has shied away from all the previous talk of 'faked global illumination' and 'skyboxes' because of prohibitive render times ( I make motion...animation... not stills, and I do not have a 'farm' for rendering, instead, I have tight deadlines and high expectations) So I think that this is a great new thing... but then I read that it took 8 mins 45 sec to render the image posted above, SHUX!

I just gave Ambient Occlusion a try and it works fine for me. Just when I turned of Multi Pass I got the same problem than pdaley. A:M just stops at 40%.

Really nice feature. Now I will try IBL.

Russel

That is because the Ambiance Occlusion was done at 100% sampling which is quite high. This, in my experience, is not required even for gray only, ambiance only, à la Arnorld renders.

I did several tests with Toys project and I could get away with as little as 15% sampling because of all the textures and colors in the scene plus the additional lights in the scene. Also to consider, is because I used Global Ambiance and Ambiance Occlusion with the Toys project, I could get rid of 3 lights from this project since a lot of those lights which were put there to help with the ambiance illumination were now done with Global Ambiance + Ambiance Occlusion. So adding GA + 15%AO increases render time but removing 3 lights from the scene reduces render time.

Also, if you use multipass, the ambiance occlusion samples are distributed among the passes which further reduces the render hit.

i tired a render with the whole Ambiance Occlusion
took about an hour to render this image at 1024x768 but its still better than the 6 hours i wait for radiosity to render
Ambiance Occlusion was set at 100%
[attachmentid=13479]

I don't know how you setup your scene but I see one important issue:

From the multitude of shadow banding I see in your render, I would think you either used some sort of lighting rig or you used an excessive number of passes. The long render time would come not from Ambiance Occlusion but from the multitude of lights or the multitude of passes.

yeah i used about 10 lights in a rig
and had 16 passes

Ambiance Occlusion is designed to replace Light Rigs. Using both at the same time is like wearing a belt and suspenders.

So is Ambiance Occlusion only to be used when you want diffused light? Evenly lit compositions?

Ambient Occlusion is ued to evenly light a scene as well as light a scene with an image like in the High Dynamic Range thread.

I was just having fun playing around with the models on the Hash Bonus CD as well as Ambient Occlusion.
I will try and do more tests to see what is generally good speed tradeoffs versus quality. I changed the lighting arrangedment a little as well.





As compared to the original scene render (As seen on the Hash Image Contest Mar 2005)

Mark,
That is most impressive. Keep investigating!

I rendered the warehouse model with AO and it turned out pretty good. The ground is solid white so it's brighter than you'd expect it to be.

How about SSS?