Fireflies happening more often

[Fat Tony]

I have noticed that i have much more fireflies in images and animation than to what i was noticing in previous builds. I rarely had to even check on it before, but lately i have this issue almost in every scene. My workflow didn't change, working on linear, not clamping anything before going to post etc.
Any idea ? Did something changed in this matter ?
thanks,
Stefan

[Zdravko.Keremidchiev]

Which V-Ray version are you using? Generally I don't think fireflies issues have increased lately, it mighty be something scene related. It will be helpful if you could send us an example scene so we could test with old an latest build to check how both versions compare in terms of speckles.

[Fat Tony]

i am having latest build, and i am noticing it in also every new scene in highlights. Hard to make a scene of these, that would take me long time and it is indeed almost every other scene. if i find some scene that would be easy to send over i will. just wanted to check in on this, because if it was one scene ok, but we have issues with strong light sources creating fireflies a lot lately.

[Zdravko.Keremidchiev]

I understand, please send a scene when available and we'll test and investigate further. Also maybe some other users can confirm this trend as well.

[Normandthegang]

Hi everyone,

This is happening to us also, it's not a big deal for still images but really noticeable on videos. We're rendering light cache and brute force.

I attached here our settings and the video as a Vimeo link. This is only one shot of the video but it happens in all our clips.
Pre rendering the light cache as fly through and then rendering the images with brute force.

We also find that the renders a quite grainy using brute force. What would be the best way to clear the grain?
Any idea where it could be coming from?

https://vimeo.com/232838850/c92fa6074e

Thanks!

Chris

[Normandthegang]

Hi everyone,
Bumping this message because we're still having the issue on a different project.

We're using V-Ray 3.50.03.

I tried another way of doing it as per Lyudmil Vanev's recommendations and now pre calculate the light cache as single frame with Use camera path on.
The problem is still there.

Really looking forward for some help as it really affect our production pipeline.

Thanks!

Christophe

[matanov]

Hi Christophe,

What happens when you render the frames that have fireflies by themselves, I mean not in an animation?

About your pipeline, you should try using the standalone denoiser tool, it's great for animations - https://docs.chaosgroup.com/display/...l+%7C+vdenoise

[anthonyh]

HI Peter,
Do we really have to *rely* on the denoiser to achieve clean images now, vray should be able to do this by itself surely ?
While denoiser can be a good tool, running it from a dos prompt is frankly awful. This needs to be a standalone app with the ability to tweak the settings *with preview* before committing it to a render. If that`s just a gui shell that calls the dos stuff that`s fine, but come on it`s not the 80s any more ! see AnotherGUI for ffmpeg as an example. Maybe it`s already planned ?
(I think this could read as `grrrr` but I assure you it`s not.)
cheers
anthonyh

[matanov]

HI Peter,
Do we really have to *rely* on the denoiser to achieve clean images now, vray should be able to do this by itself surely ?
While denoiser can be a good tool, running it from a dos prompt is frankly awful. This needs to be a standalone app with the ability to tweak the settings *with preview* before committing it to a render. If that`s just a gui shell that calls the dos stuff that`s fine, but come on it`s not the 80s any more ! see AnotherGUI for ffmpeg as an example. Maybe it`s already planned ?
(I think this could read as `grrrr` but I assure you it`s not.)
cheers
anthonyh

No, I'm not talking about relying on the denoiser. I'm just pointing out, that is a great solution for animations, since there are a lot of frames that can be rendered with a higher noise threshold to save some render time.

About the UI, yes it's planned

[anthonyh]

HI Peter,
great to know, thanks.
anthonyh

[Normandthegang]

Thanks guys for your reply.
I'm just starting to use denoiser more and more and really like it! (although it doesn't work so well through glass)

Yes I can see the white dots when I just render a still image.

Chris

[Normandthegang]

Hi everyone,

I uploaded my file here http://www.mediafire.com/file/62dnml.../SceneOnly.zip
If anyone has a chance to have a quick look at it and see if anything stands out as being potential a potential problem I would be really thankful for the help!!!!

As I was saying earlier I have that flickering happening in most of my videos now. We used to render lc/irr but recently switched to lc/bf and it seems like the problem started happening then.

Thanks.

Chris

[Fat Tony]

try,
Move scene to 0,0. no need to be so far from there. enable retrace and set it to 8.
I had also issue with GI flickering and have set LC subdivs to 3000 and it helped.
Also if you move camera try fly-through mode.

This is not the issue of fireflies tho. Fireflies are issue of burner out pixels and that comes usually from overexposed lighting or super shiny materials. But that goes from case to case so hard to tell.

[Normandthegang]

Hi everyone,

Sorry I kind of disappeared since last posted as we were working on a few videos and still trying to fix our flickering issue.

We updated our farm to the latest version of Vray and unfortunately the problem is still happening. It does happen on different scenes and it seems like moving the scene to 0 or setting the raytrace to 8 or lc to 3000 doesn't fix the issue...

I think that the problem is coming from the sample rate in some ways. I rendered the sample rate pass and the flickering happens on the zones where the sample rate pass is red.

Increasing our min/max samples from 1/24 to 1/100 seems to make things better but it's still far from being perfect.

I even rendered a scene without moving the camera or any object and it still does flicker. I uploaded the sample rate pass, the beauty pass and the file on Mediafire for you to see what's happening (this is a zoomed in version of the video which explains the heavy blur on the image).
The scene is lit with a VraySun and the sun is set to invisible.

https://www.mediafire.com/folder/x6xz42wh5rms4/171127



Please see below my settings. I first render a light cache pass with "use camera path" as single frame and then use that pass for calculating the overall animation on bf/lc.


Any help would be appreciated as we're at that point where it's really becoming a problem. We can't deliver a video with fireflies to a client....

Thanks in advance for your help!

Chris

[Normandthegang]