Ambient Occlusion VS. G.I. (3D Studio Max)

[Marty_McFly-3DT]

I'd just like to see what people think of these two images compared side by side.

The first will was rendered in two passes (a standard render and an Occlusion pass) and composited together, the second was rendered in one pass (with Global Illumination).

This is my first test using Ambient Occlusion so please post any opinions and questions. (Or techniques!)

[Marty_McFly-3DT]

First Pass: 15 second render, 1 omni light (Specular only)
(Standard Render)

Second Pass: 45 second render
(Ambient Occlusion Pass)

[Marty_McFly-3DT]

Only Pass: 2 minutes 45 seconds render, 1 omni (Specular only) and 1 Skylight (default settings)

[DeadlyFreeze]

GI still looks better, but then why wouldnt it? Ambient Occlusion is the quick and dirty, so you will never get to the range of GI quality.

[Marty_McFly-3DT]

Originally Posted by OmegaN

Marty_McFly: Yea if you do skip GI and only use A/O your rendertimes will fall dramaticly, but A/O will not make the picture just improve it, you will still need GI for more light complex scenes like interiors etc (or fake GI). It is really fun to see the results when you have a interior scene with GI etc and then use A/O the image goes up a notch And the rendertime of the A/O is nothing compared to the diffuse layer so its well worth its extra min =)

So to my conclusion is that you can never replace GI with A/O if your looking for good results but its really good for giving images that extra touch. This dosnt mean you CANT do it, sometimes you just dont need/want to use GI and using only A/O is really making a difference. I always use A/O in some sort even if im doing a cartoon pic/animation or whatever

Maybe you should have a third pic in your thread that is both GI+A/O? Because thats the most common usage of it.

Through OmegaN's suggestion, I combined my Ambient Occlusion Pass to my Global Illumination render. What do you think?

[RideStowe]

its hard to tell from such a crappy scene, hehe j/k can we just see a clay teapot?

[Marty_McFly-3DT]

Ok RideStowe... here's your stinkin teapots.

[Mr. Bluesummers-3DT]

Hands down, I prefer GI. But consider, also, that you could be comparing Scanline General Illumination, Scanine Ambiant Occlusion, mental ray GI, and mental ray AO. The quality differences are about the same, but the time should be quicker in both cases. I prefer GI over Ambiant Occlusion any day because the former has smoother results. Ambiant is too choppy for my tastes, and doesn't react properly to unsmooth geometry.

That's my 2 cents.

[RideStowe]

gi with occlusion looks best imo. gi itself doesnt have enough shadow to it and the occlusion adds to it really well.

[messiah khan]

I agree, the GI+AO is the best i recon. Also with the AO being a seperate image, the shadow balance can be tweaked extremely easy in photoshop.