Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: jhindley on 2014-07-01, 21:50:02
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Hi Guys,
First post from me having now used A7 albeit with the demo scene.
I have posted my results here for comment.
I have rendered out the test scene with A7 on Max 2015
I am using a i7 with 8GB Ram
The render was set to stop at 500 passes and I am pretty damned happy with the 1080 render
given it looks pretty clean to me after 2 hours 6 mins.
My question relates to the artifacts in the door frame on the left side of the image.
Is this likely to be something that gets better with more passes or is there something I can tweak to get rid of this.
As I say i think the rest looks clean enough - I would just like to get rid of this artifacting
Any help / advice welcome
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That's not an artifact, just noise. It's the slowest converging portion of the image. It's due to the direct environment light having difficult path to reach that area. You can increase light samples multiplier to let's say 4, and let it cook a little bit more. The scene is fairly fast, so letting it go for say 200 more passes should not hurt.
Alternatively, you can just region render that small part with noise, and it should go very quickly away.
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Thanks for the quick reply
Where can I learn how to region render a portion and have it add that to the over all image.
I believe this is possible ???
I mean can i render the $h17 out of that area and then keep that part and continue to render the rest of the image ?
If so where do I learn how or can anyone tell me how quickly ?
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James,
At the moment you have to do the comping in post production, but I believe it is part of the roadmap for corona
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It is actually ultra-easy:
I've made a quick video to show you how:
https://www.youtube.com/watch?v=1FzWevplrI0 (https://www.youtube.com/watch?v=1FzWevplrI0)
There's only one important thing to keep in mind. Due to the bug in VFB, when you render region, and then click save, it will only save the region, EVEN if there is some remaining data from previous render outside of the region. It will always save just region with black around it. But luckily, you can work around it by clicking Ctrl+C button and pasting it in Photoshop, or even MS Paint ;)
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Thanks guys,
Good evening Mr Jones - good to see you
Rawalance - thanks for the vid
Ill give it a whirl. The machine is currently balls deep rendering out that scene again but this time I upped the setting to 4 as you suggested.
I also gave it another 200 passes so we shall see what the result is like.
I think in production if i was pushed I would region render and comp as you suggested -
I am just getting a feel for the renderer as this is literally the first thing I have hit F9 on it ages
I will post my result with the amended settings and we shall see.
Thanks again for your advice
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OK - so light samples multipler jacked up to 4
I gave it 700 passes this time - this is full screen render not region and not comp'd
Have a look - im still not happy with that area
any ideas
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Ok
Using region render and compositing the layers in PS i have done some tests
I have jacked up the light samples multiplier first from 2 to 4, then from 4 - 6 and finally to 10
I have then rendered out 1000 passes of the region before putting it together in PS
I am still not happy with how this is looking. Any further suggestions ?
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try decreasing max sample intensity
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I don't see any noise. If you do, and are not happy, then make yourself your own scene :)
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Alright.. so.. there is a "problem" in that scene.. There is an opening that lets sun go through without a portal and it is exactly lighing that specific area... solution, place a plane covering that opening and assign portal material to it..
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Yes, if you look at the sofa, there is a hole between the back seat cushion and the shelf, and blue light from sky comes through that hole. Only artifact there is noise. If there is no noise, then that's how it would look in the real world.
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Do this (picture).. or close off that area completely if you want.
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I don't see any noise. If you do, and are not happy, then make yourself your own scene :)
I note the smiley so I know you don't mean that in a nasty way -
I don't know nearly enough about Corona right now to even pass judgement on anyone's scene
I am at the empty room with a tea pot and sun system in it sort of stage right now. :)
I thought your demo scene was excellent and I have enjoyed looking at the settings - the materials and playing with the renderer
It has helped me get a good understanding of the renderer in a very short space of time.
I can see the effect the portal has on the image and I now understand its about the way the direct light penetrates the scene.
I have learned from this and I can now make my own scene to start using as my own test bed.
I hope I can post that scene up when finished for other people to test with.
Lets see where I get to.
Thanks again for your help -
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It is actually ultra-easy:
I've made a quick video to show you how:
https://www.youtube.com/watch?v=1FzWevplrI0 (https://www.youtube.com/watch?v=1FzWevplrI0)
There's only one important thing to keep in mind. Due to the bug in VFB, when you render region, and then click save, it will only save the region, EVEN if there is some remaining data from previous render outside of the region. It will always save just region with black around it. But luckily, you can work around it by clicking Ctrl+C button and pasting it in Photoshop, or even MS Paint ;)
Interesting Rawalanche - I followed your tutorial video on region rendering
when i regioned out that area behind the book shelf and then hit control c and paste into photoshop the entire render came with it - not just the small area
I did not get the black box issue -
My test image in photo shop is now a series of renders layered over my original "noisy" render but each is the full scene render
Has this been addressed in A7 or something because I dont get he same issue you mentioned
The ability to region out a trick part of a shot and then continue with that part done and build the rest of the image around it will be cool.
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I don't see any noise. If you do, and are not happy, then make yourself your own scene :)
I note the smiley so I know you don't mean that in a nasty way -
I don't know nearly enough about Corona right now to even pass judgement on anyone's scene
I am at the empty room with a tea pot and sun system in it sort of stage right now. :)
I thought your demo scene was excellent and I have enjoyed looking at the settings - the materials and playing with the renderer
It has helped me get a good understanding of the renderer in a very short space of time.
I can see the effect the portal has on the image and I now understand its about the way the direct light penetrates the scene.
I have learned from this and I can now make my own scene to start using as my own test bed.
I hope I can post that scene up when finished for other people to test with.
Lets see where I get to.
Thanks again for your help -
Yep, i indeed meant it as a joke. You have +1 point for not being oversensitive like some of other users on this forum :)
My point was that if you were to make your own scene, you would likely run into other scenarios, where you would see something you would consider an artifact.
People coming from renderers with interpolated GI, such as Mental Ray, will not often be used to so accurate light simulation, and consider some of the occurrences artifacts, while they are just regular effects of physically plausible lighting, which their previous too biased renderer was not able to deliver.
You will rarely run into splotches or smudges with Corona. Even if you start to see some in corners, it's likely a scenario with some Cad model where walls aren't really air-tight, so some light leaks through the narrow gap.
Portal does not change looks of image in any way. It's purely performance tool. Basically a marker for renderer to point it where it should sample with more rays.
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I hear you - People get upset far too easily.
Thanks again for the advice - just running a region on that area with a portal at the door
No doubt i will create some really weird situations.
I understand now this is not artifacting - i just need to get used to this render engine -
like the software so far - and its only early days
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Ok -so to conclude this
The portal added and a region render done
Light samples multi set to 4 and only 300 passes done on the region
I have composited that region onto a generally clean render and its looking spot on to me
Thanks for the help - renders attached
Informative and useful - thanks guys