Flicker-free splotch issue

Corona Corona for 3ds Max Help Required
1

Hello,

I am currently doing a film with corona 1.5 and I have a problem of significant flickering.
Here is a video that shows the problem. the compression of the video makes it less visible flickering but it is present
I had already made videos without using a cache and I did not have much problem now.

animation are calculated by frame on a render farm.

The setting is :
1080P
200 passes
mode flicker free without cache
denoise 1.8
précision : 2.0

you have a solution for this problem ?
I have this problem on many scene but less on the outside scene

2

Bet you $5 you have coronalightmaterial in your lamp set to Emit light. Turn that emit off and your flickering will be gone. Naturally do this for all other emitting materials too.

3

Sorry, there is indeed a standard corona light :smiley:

if you look in detail, it is not just the lamp that bug. the kitchen wall, curtains, sofa and lots of other little detail.
here is a link to download the uncompressed version for better view of the problem.
http://projets.valentinstudio.fr/test/exemple_1.zip

Here’s another example with a more visible problem.

here is a link to download the uncompressed version for better view of the problem in this second shot
http://projets.valentinstudio.fr/test/exemple_2.zip

I’m really annoyed with this problem :frowning: :frowning: :frowning:

Thanks you for your help

4

Yes I started noticing this problem in my animation, is quite annoying.
Is it something relate to the new version of Corona I suppose.
But do you use displacement in the scene and the denoiser?
I read somewhere that the could be the reason for this.

5

there was a bug in uhd cache in 1.5, we fixed it. Stay tuned for hotfix2

6

Interesting… under what conditions does this happen? We’ve been doing quite a lot of animation rendering on 1.5.1 and had flickering but it was solved by fixing user error. We’ve not noticed it happening with no obvious reason.

7

Where is the fix implemented? Is it already in 1.6 dailies? We have to do much animation stuff next weeks and currently I encounter strange uhd cache problems with 1.6 in test animations. Trying to sort them out right now.

Good Luck

8

currently we are testing the fix internally, but it is not released to public yet. I hope next week it will be available both in daily builds and in hotfix2 stable

9

So it seems I can stop the investigation and wait with testing until next week. Still making me friable. I hope this weirdness is really connected to that bug you mentioned, thanks,

Good Luck

10

Anyone with this problem can try pasting this into string options:

float gi.uhdcache.precision = 1
float gi.uhdcache.precompDensity = 1
int gi.uhdcache.interpolationCount = 5
int gi.uhdcache.recordQuality = 512
float gi.uhdcache.normalSensitivity = 2
float gi.uhdcache.dirSensitivity = 3
float gi.uhdcache.glossThreshold = 0.9
float gi.uhdcache.strictness = 0.075
float gi.uhdcache.msi = 3
bool gi.uhdcache.correlatePrecomp = true

I haven’t yet received any confirmation if it does the trick though…

11

Thanks maru, this helped. Does the fix itself consists only of those UHD tweaks, or the other way round: Do I get the same results applying those settings as if having the fix?

Good Luck

12

Really thanks guys!

13

I think that the hotfix 2 will change the default settings in the UHD cache.
So, we will not have to apply these settings again.

14

I remember very similar issue with messed uhdcache strings when save defaults was introduced in dailies for the first time. Curious if that’s the same bug again or different issue?

15

You mean the new hotfix version? AFAIK it just has different defaults, so the old (incorrect ones) are not loaded in new scenes. But if you saved a scene in 1.5, and it had those wrong settings, then I am afraid they are baked into the file, and you will have to press the “reset settings” button in scene setup. At least that’s how it is working now. Would be great to have some kind of automatic detection and automatic fix for this.

16

Yes, I was refering to hotfix 2.

Detection would be enough. Atm I find myself resetting scenes + readjusting all the time because I can´t see if a scene is “infested”. Any option to find out at least manually?

Good Luck

17

Look at UHD cache settings, if precision is set to 0.4, there’s a good chance that scene is affected by the bug.

18

Thanks romullus, indeed I noticed that value in some scenes but - corrected it with a shrug and - saved :frowning:

So I deleted the last clue without knowing it. But I will continue to pay attention to this. Well, seems there must be some risk left using dailies in production…

Good Luck

19

One solution to be always sure that the settings are correct is copying them from a healthy config file (e.g. created in 1.5.2) and pasting it into the string options window for any suspicious scenes:


Float gi.uhdcache.precision      = 1
Float gi.uhdcache.precompDensity      = 1
Int gi.uhdcache.interpolationCount      = 5
Int gi.uhdcache.recordQuality      = 512
Float gi.uhdcache.normalSensitivity      = 2
Float gi.uhdcache.dirSensitivity      = 3
Float gi.uhdcache.glossThreshold      = 0.9
Float gi.uhdcache.strictness      = 0.075
Float gi.uhdcache.msi      = 3
Bool gi.uhdcache.correlatePrecomp      = true
20

Ok, if there is no other option I will spam our default startup scene with string options, maybe omitting the precision setting which would override the UI value if there is really no other way to find out.

Good Luck