Author Topic: Fireflies!  (Read 3711 times)

2019-02-15, 21:46:38

eriklint

  • Active Users
  • **
  • Posts: 6
    • View Profile
Hi all,
This is my first post to this fabulous forum.
I have been unable to de-firefly my image, and there are a lot of them. I am hoping I can get some clues/help from the group to help me better understand the process.
I am posting a section of the rendering and some settings related.
Any pointers are appreciated.
Thanks!

2019-02-19, 11:57:11
Reply #1

Beanzvision

  • Corona Team
  • Active Users
  • ****
  • Posts: 2872
  • Bengamin
    • View Profile
    • Cormats
Hi there,  this could be a range of things from incorrect material or lighting setup, can you possibly share your scene with us via our private uploader? The link is in my signature below. Thx
Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us
Corona Uploader l Upload
Portfolio l Click me!

2019-02-19, 15:50:36
Reply #2

Ealexander

  • Active Users
  • **
  • Posts: 149
    • View Profile
    • evan alexander
My professional unprofessional guess would be that you have a low light, high contrast scene there and since you've limited it to 18 passes and it would probably take more time/passes to clear it up....

2019-02-19, 16:42:55
Reply #3

eriklint

  • Active Users
  • **
  • Posts: 6
    • View Profile
Thank you Beanzvision and Evan.
Unfortunately the project is tied up with NDAs and it would take me some time to strip out the "secret" stuff, so I can't post the file. Thank you beanzvision for suggesting and offering.
Evan (Erik here btw), thank you for the very accurate analysis. It is indeed a low light, high contrast situation. I am going to try two things. More passes and then also adding more light and then adjusting to get the drama in the post effects. I have this file set up for Lightmix too, so I will try that too.
Oddly enough, since this isn't 100% about photorealism, the fireflies added some detail/sparkle/something in the shadows that actually helped with the final presentation rendering. That being said, my professional curiosity would like to scrub them out.
I really appreciate the generous and helpful replies.
Best,
Erik

2019-02-21, 10:22:13
Reply #4

Konichowaa

  • Active Users
  • **
  • Posts: 86
    • View Profile
what is your light setup?
do you have by chance a hdri as a background (without GI/shadows)?
I once had a project where I had unexplainable fireflies in some blurry reflections, that no matter what I tried, I couldn't get rid of. The fireflies also became worse and worse the longer I rendered (kept appearing new ones).
I had a scene setup with HDRI for lighting and another HDRI for background (without GI/shadows). I spent more than a day searching... When I finally tried to put the high-res JPG version instead of the HDRI for the background the fireflies were gone ...
Koen Van haesendonck
3D-lab - www.3d-lab.be

2019-02-21, 18:54:38
Reply #5

eriklint

  • Active Users
  • **
  • Posts: 6
    • View Profile
Thank you Konichowaa!
I think your suggestion was a good one. My lighting setup was indeed mostly an HDRI with a Corona compositing tag with an illuminating skyline backplate (also with a Corona compositing tag.) I already did a quick test and it reduced the fireflies by a lot. I am slammed with a deadline at the moment and will fiddle with the jpeg option when I get some time.
Great idea, thank you!!
« Last Edit: 2019-02-21, 21:41:36 by eriklint »