Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: andych82 on 2015-11-18, 23:53:10
-
Hey all,
I've been evaluating Corona for 3DS Max the past couple weeks and have been really enjoying the engine. The interactive renderer and ease of use for great images are fantastic.
I'm new to the renderer so I'm still learning its nuances, but to evaluate for my professional use, I've been trying out test scenarios that I've encountered to see how they perform with Corona.
I made a super quick test scene with simple light animation that I was planning on rendering out to a sequence, but am finding that the object in low lighting is coming out far more noisy than the object more fully lit.
Is this normal for the renderer? Is this a case where I just need to wait for more passes to clean up? I've also increase the GIvAA setting, at tweaked a few things beyond the default settings, lowered the material albedo but overall still found too much noise for my taste in low light.
Do you guys think if I've set things up incorrectly, or are there are things I can do to clean up low light noise?
I've attached 2 images, both rendered with pretty default settings, one with the object more lit and one with the same object with less lighting.
I'm happy to upload the scene too if that's helpful.
Thanks for your help.
Andy
-
Someone will correct me if I'm wrong, but I think this is more or less as expected and the same issue with other renderers. When there is low light there is a low degree of contrast between pixels, so the renderer has a much harder time, relatively speaking, trying to interpolate/anti-alias between those pixel values. Your brighter image has much more lighting information and detail and therefore contrast across the image, so the renderer will have less trouble anti-aliasing those areas. In other words you're giving the renderer more information to play with. Think of it like trying to learn a language. If you have only half the dictionary it's going to take you longer to learn the language than if you have access to the full dictionary, even if you are able to work out what's missing based on the general concepts. Vray works the same, more or less and I imagine most other engines.
It's the same with real world photography too. It's often desireable to shoot a subject/scene with subtle fill lights and then darken those areas back down in post to get the desired, noise-free look.
This is one of those areas that we're all hoping that Render Legion will be able to improve with adaptive sampling, so the renderer will work out which areas of the image need the most time to clean up and then prioritise those, to avoid wasting samples in areas that are "clean enough" already.
I'm sure others can chime in with better info on this topic.
-
Ok cool, thanks for looking into it. Sounds like your solution is to add some fill lights and maybe lower the exposure to decrease noise.
Will try that out.
Andy
-
Ok cool, thanks for looking into it. Sounds like your solution is to add some fill lights and maybe lower the exposure to decrease noise.
Will try that out.
Andy
No problem, but I don't think lowering the exp will have any effect on the noise. If anything it might make it worse.
-
Hi, I wanted to take a look at this, but the link got lost somehow, sorry. :)
I think that this scene contains too many "fakes" for Corona - I am just guessing now, but it looks like there glowing object is using Corona Light Mtl, and it is intersecting with some glass or metal object. You should probably use Corona Mtl with self illumination enabled for this, and you can use rayswitcher to exclude the glass/metal part from GI calculations so that it won't cast reflective/refractive caustics. It would be great if you could post a new support ticket and send us the full scene: https://coronarenderer.freshdesk.com/support/tickets/new
We would move the discussion there, and then post the solution in this thread. How about that? :)