Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: Goga abramia on 2018-01-16, 13:40:19

Title: AO error
Post by: Goga abramia on 2018-01-16, 13:40:19
When i render this picture with render view, "ao area" everityng is black, but final render works ok
Title: Re: AO error
Post by: houska on 2018-01-16, 13:57:39
So it's a material that renders as black in some case? But what does AO have to do with it? Can you reproduce it in a simple scene - e.g. just a cube with the incriminated material - and send us the scene?
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 14:13:56
So it's a material that renders as black in some case? But what does AO have to do with it? Can you reproduce it in a simple scene - e.g. just a cube with the incriminated material - and send us the scene?

yes i can upload the exapl file now and you can see it :) Thanks
Title: Re: AO error
Post by: houska on 2018-01-16, 14:25:18
Thanks for the scene! I reproduced the problem imediately and will look at it.

Just a thought about your workflow - why is the AO and Normal shader in Layer necessary? You do know, that Corona will render the AO for you out of the box without adding a special AO shader, right?
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 14:32:58
Thanks for the scene! I reproduced the problem imediately and will look at it.

Just a thought about your workflow - why is the AO and Normal shader in Layer necessary? You do know, that Corona will render the AO for you out of the box without adding a special AO shader, right?

i know only one step,ao shader in layer, Where i find ao option in corona?  :) Thanks :)
Corona dosn't have AO in GI Like vray and because i use ao in corona with corona ao shader :)
Title: Re: AO error
Post by: houska on 2018-01-16, 14:39:58
This is really strange, it must be some kind of a bug. Your material looks strange only if the albedo is set to 100% (the left portion of the image). If you lower it to 90%, AO suddenly appears (right part of the image). From what the core guys are telling me, albedo above 80% is unnatural and you should avoid it to get realistic results.
Title: Re: AO error
Post by: TomG on 2018-01-16, 14:41:21
I know (from past experience when freelancing) that some clients just want the "AO look" even though Corona is already calculating realistic lighting.

One thing, if you are applying AO to your entire scene, usually easier to add it as a render element. Corona menu, Multipass, check Enbl to enable render elements, add a Texmap, and add the Corona AO into that, then can blend the AO pass over the image in post. As a note, this doesn't work in the current beta, but did work previously and will work again :)

On the albedo, yes 100% albedo is a bad thing, can slow rendering etc. - you can use Multipass to check that too, add an Albedo pass and any problem areas where albedo is too high will be highlighted in red.
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 14:43:35
This is really strange, it must be some kind of a bug. Your material looks strange only if the albedo is set to 100% (the left portion of the image). If you lower it to 90%, AO suddenly appears (right part of the image). From what the core guys are telling me, albedo above 80% is unnatural and you should avoid it to get realistic results.
yes i guess it :) but enivey when i want more black areas i use ao and anywey ao dosnt work in render view :)
Title: Re: AO error
Post by: houska on 2018-01-16, 14:46:49
Yeah, that's true. It should work, even if what you want is unrealistic :-)
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 14:50:14
Yeah, that's true. It should work, even if what you want is unrealistic :-)
:D Why unrealistic? ao is perfect thing for more details :)
Title: Re: AO error
Post by: houska on 2018-01-16, 15:01:09
But AO is a phenomenon that Corona can simulate accurately. You don't need a special shader for it. It works out of the box, it's just hidden by the reflected light if your material is 100% white (which does NEVER happen in real life). Just try to lower the albedo (brightness) to 80% and you'll see AO even without any AO shader hacks. Lighting should be simple, ideally you shouldn't ever feel the need to use any hacks like this.
Title: Re: AO error
Post by: houska on 2018-01-16, 15:06:50
Look what I found :-)
https://forum.corona-renderer.com/index.php?topic=2359.0
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 15:08:13
But AO is a phenomenon that Corona can simulate accurately. You don't need a special shader for it. It works out of the box, it's just hidden by the reflected light if your material is 100% white (which does NEVER happen in real life). Just try to lower the albedo (brightness) to 80% and you'll see AO even without any AO shader hacks. Lighting should be simple, ideally you shouldn't ever feel the need to use any hacks like this.
Thank you my friend for your anver,but sometimes it need for artistic renders :)
Title: Re: AO error
Post by: houska on 2018-01-16, 15:11:42
Well why didn't you say so in the begining? If it's art, then you can get away with anything.

But jokes aside, the black AO shader really needs to be fixed, I'm looking into it already. Thanks for the report!
Title: Re: AO error
Post by: Goga abramia on 2018-01-16, 15:14:10
Well why didn't you say so in the begining? If it's art, then you can get away with anything.

But jokes aside, the black AO shader really needs to be fixed, I'm looking into it already. Thanks for the report!
:))))) you are welcome my friend :)
Title: Re: AO error
Post by: Eddoron on 2018-01-16, 17:11:15
Thanks for the scene! I reproduced the problem imediately and will look at it.

Just a thought about your workflow - why is the AO and Normal shader in Layer necessary? You do know, that Corona will render the AO for you out of the box without adding a special AO shader, right?

It's great for masking.