Dancing Fireflies (I Think)

[BigAl3D]

So here's a short clip of a scene I just rendered. Overall, I'm very happy with the results, even with my limited knowledge of Corona. In this section of the animation, we're seeing a lot of movement in the chrome bars along the sides of the screen. There is no movement at all at this point in the scene. There are a few lights around as you can see in the screen shot. I don't believe is the standard idea of dancing noise, since there are many areas in this shot that are perfect for dancing noise yet there is none. I tried rendering as high as 60 passes with and without denoising. Still they dance. Follow the link below to see the clip. Yes, I did also try the Flicker Free option as well with same results, which seems to confirm to me that is't not really noise, but maybe fireflies. Not sure how to tackle them. I will say in this instance, I can just use a still image when it's not moving, but I'm sure I will need to move the camera at some point. I'm also uploaded the scene for you to examine. Thanks for your help.

https://bit.ly/2TLarbx

[TomG]

I get a "sorry we couldn't find that page" from the Vimeo link.

[BigAl3D]

Hmmm. I tried another Vimeo link and it comes up as "Not a valid Vimeo link." If I try it in a browser I'm not logged into, it works.

I posted a Bitly link. Try that. Thanks.

[TomG]

That worked. Best bet would be to upload the scene. Seems only to happen in the right and left structures, so I wonder if there isn't some strange geometry there, overlapping faces or something (though that seems unlikely, but never hurts to ask). Does look like the UHD Cache (have you tried baking it to see if that changes the result, or use Path Tracing instead? That would narrow down possible causes).

https://help.c4d.corona-renderer.com/support/solutions/articles/12000033461-how-to-report-issues- if you want to upload the scene.

[BigAl3D]

Good idea to check the geometry and the Path Tracing. How would baking help this scenario? There is also some larger areas when the car shows up rotating that seem to change brightness, but I forgot to enable the Flicker Free function so not sure that would fix the problem there.

I did upload a scene already and linked to this thread. :-)

[TomG]

Baking means that the UHD Cache is only calculated once and can't change from frame to frame (so can't flicker - if it does still flicker with a baked UHD or Path Tracing, it can't be the UHD Cache causing the issue :) ). And ty for uploading!

[BigAl3D]

Also, the most visible jumpy parts are only on the bright reflections/highlights. I keep getting errors when I try to combine my image sequence for the entire :30 sec. clip. I'll try again.

[TomG]

I have missing plugins on load, with these being:
CV-ArtSmart Pathinfo
CV-ArtSmart Object

When I render, I get a very different result from you, not sure if this is due to the missing plugins or something else (see attached). Unfortunately that means I can't try to duplicate your results at the moment :(

[BigAl3D]

The Artsmart plugin is free from Cineversity when you set up even a free account. I'll PM you a link. But, that plugin is only used for the Illustrator logo later in the scene. It allows you to import any vector, add depth, space out the layers, even import the colors. Anyway, that wouldn't have anything to do with the lighting I see in your test. That doesn't make sense.

Seems like... wait. I got it. I used an IES file for the light objects. It lives in the Visualize.lib4d, but you should have that if you have Studio. Maybe you didn't install the Content Browser libraries? Just go to update and if you don't have them already, you'll see them listed and just click update. That particular library is around 3.5 GB. I don't know how to extract that one file from the library.

Worst case, you can turn off the IES function.

[Beanzvision]

I think I have their plugins somewhere, I'll have a search and try and test out the scene. ;)

[TomG]

I turned off the IES, but had to raise the light intensities to around 40 to start to get something close :) Not sure I can find the IES stuff in the content browser (as it's a beta / test  / developer version of C4D that I have on my machine, not a regular install). Going to ignore the plugins since they are related to something specific that shouldn't have a bearing here. Anyway, will see what comes out with no plugin, no IES, brighter lights.

BTW, what happens if you render without the IES, just out of interest?

[BigAl3D]

Ah, identical to the image you posted. Good call. I understand I have a lot to learn about Corona in order to get the best out of it, but I'll keep at it.
Thanks for taking a look.

[TomG]

Just in case there is confusion - in the image I posted, everything was as received and too dark. I have since turned off IES and raised brightness, and now get an image much like yours, and can see the effect. It isn't the UHD Cache as setting things to PT doesn't resolve it. It isn't the expression on the lights, removing that doesn't resolve it. So, still looking :)

[TomG]

Either the camera or the screen is actually moving. I deleted animation keyframes for both, and the effect disappeared. I haven't tested each individually. It looked like there was one keyframe when they should start moving, but no keyframes before that, so it could be there was some "ease in" effect that means it is moving before the first keyframe. You might try either setting another keyframe one frame prior to before they move (just copy the keyframe at where they start moving, so that it stores the same data twice), or copying the keyframe before they start moving at frame 0 (or both).

[BigAl3D]

Yes, now I see the screen group comes down and rotates, but it only spins to -0.4° then SLOWLY rotates to 0.0° at frame 339. My mistake. If that will solve this case, perfect. BUT, what if I WANT a slow camera move. Corona shouldn't produce this much dancing right, otherwise that is a major limitation. You mentioned baking earlier. So if I render without the beauty pass and save the UHD Cache, is this what you mean? If yes, then how to handle the first section where I animate that back light from 0 — 40?