Ambient Occlusion differs from day to day

[John Bigboote]

I love the look that AO can give... but getting there is killin me! Friday I set up a AO render and let it fly all weekend... it was taking an hour per frame... not bad- I have some time to render this sequence. TODAY I am trying to do the same thing and NOT getting the same results (See image)

 

Let me tell you how I go about getting AO and please check me if I am missing something:

 

-Open up project and turn OFF or delete any existing lights.

-Set the CHOR to GLOBAL AMBIANCE TYPE- COLOR

-Adjust the color to an off-white, set the ambiance intensity to 70-90 ish

-set the ambiance occlusion to 20-40 ish (higher equals longer renders...)

-In the RENDER cue... turn ON Ambiance Occlusion under Options

-render

 

I know there is also a way to get an AO pass using EXRs... I am mixxing my passes in After Effects... what am I missing here???

[HomeSlice]

Are you rendering with Multipass ON?

[detbear]

John,

 

I just finished rendering a half hour childrens video with AO at HD 720p. The Characters were all rendered separately from any backgrounds. And ground shadows were also rendered separately. About 3-6 months of rendering on and off. I didn't use Open Exr's(But they are really cool) The characters on separate passes allow for more flex in the composite. Trade off was that sometimes the ground does not have AO shadows even though the character does. BUT this can be faked by adding a layer in AE. Also requires no real render time in Hash.

 

Your process looks pretty good....I used Multi-pass from anywhere between 9-25passes. Also I kept the AO sample at 30%. I used 1 or 2 additional lights along with the AO lighting. For some sequences I used Image Based lighting with an HDRI image. Depending on the complexity of the model(s) and lighting, renders of characters took anywhere from 10-40 minutes.

[John Bigboote]

HOLMES-I am always going back-n-forth between MP and regular renders... I try it both ways most of the time before I render to see which will suit better- always with varied results.

 

DETBEAR- Wow...I'd like to see your show!

 

Thanks!

[detbear]

Stay Tuned .....

[HomeSlice]

HOLMES-I am always going back-n-forth between MP and regular renders...

Holy Moley, would you look at that? AO now appears to render with Multipass ON *or* OFF (just did a test). I'm pretty sure that in previous versions, it only worked with Multipass ON. I still don't know why you got different renders, unless you rendered one version with MP ON, and the other version with MP OFF.