Chaos Corona Forum
Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: 3dkobi on 2019-09-08, 06:14:13
-
I'm rendering an animation of a product, and I get flickering from the bloom&glare in some areas...
The flickering is in the top right corner in the green buttons. The material of the buttons is just color+self illumination.
When I rendered a short small test of this shot I didn't had flickering. I also rendering now other shots of this product, and I'm not getting flickering...
All the settings in corona render settings are at default. GI solver - UHD cache with secondary GI preset set to Animation.
Any idea\solution ?
-
Which version of C4D, Corona, which OS, and other related info is always good :)
Bloom and Glare is based solely on the pixel intensity, so unless pixel intensity changes, bloom and glare should be the same. I am also a little confused about the last 2 reports that say you are now getting no flickering - what are the differences in those two shots? Purely different camera angle? Different resolution? They aren't using Team Render but the first test was? What format were you saving to? Can you share an example of the animation with the flickering? Can you share the scene?
See https://help.c4d.corona-renderer.com/support/solutions/articles/12000033461-how-to-report-issues-c4d for useful info to always include, plus info on the private uploader for sending scenes etc. that can't be shared publicly.
The two still images appear to be from a slightly different location as if the camera is animated, but would kind of need to know more about what is being animated to say much (which is why scene or sample animation would be good). You could try lowering the threshold in bloom and glare, in case it's something like an apparent variation in intensity that is taking the pixels below the default threshold, as the only idea I have for now with limited info :)
-
Ok, sorry for the missing info...
C4d 20.059, corona 4 hotfix 1, win 10 on pc, no TR.
The intensity of the self illumination channel is never animated. only the camera is moving.
It's an internal project I'm doing, so I render to jpg sequence. The difference between the shots is the camera movement + small differences in lights intensity&position.
Nobody ever reported this issue ? I can upload the scene, but I already changed some parameters. I'll find some time in the next 2 days and render this shot again and see If I get this flickering again and report here
-
No issues reported that I can think of off the top of my head. Could just be that the strip is 1 pixel wide in one part of the animation, then grows to 2 pixels wide as the camera moves, resulting in a stronger bloom and glare calculation as it gets wider, but impossible to say without seeing the animation. That's why I was wondering if lowering the threshold might work, causing the thinner strip to "trigger" the bloom and glare more easily - but all just guesses at the moment :)
-
Hi TomG,
So I rendered the first shot again, and I still have this flickering issue (Animation attached)
If you don't have an idea whats causing this - I can send the scene file - the model is an old one from evermotion.
-
Did you by chance render the bloom and glare as a pass?
Seeing just the bloom and glare and the beauty(without B&G) layers separately might give a clue as to what's going on.
Uploading the scene file would be helpful as well.
-
Did you by chance render the bloom and glare as a pass?
Seeing just the bloom and glare and the beauty(without B&G) layers separately might give a clue as to what's going on.
Uploading the scene file would be helpful as well.
No, I didn't render them as separate passes...I didn't know it was possible (I know now after checking)
I also can't share the scene in public
-
Could you save two consecutive frames to CXR that shows flickering and attach them to the forum? It would be interesting to see at pixel values inside CIE.
-
TY for the animation! Hard to say really, does look like something to do with anti-aliasing or similar, but other things that stand out are that it seems only to happen to the green color (the white button in that area doesn't show the effect). I'd still try lowering the threshold as a first point, but would also be interested to see it without bloom and glare and see if those lines are showing variations in thickness and see how the anti-aliasing looks there. The threshold might still be relevant since the green will naturally be less bright than the white.
Sending the scene via private uploader never hurts, someone in the team can take a look and maybe have more ideas and test a few things.
Might also be interesting to know if the New Image Filtering was used (as it takes place across 2 pixels width, rather than the old Tent etc. which only affects one pixel - this might lead to changes in the apparent width or "spill over" from the green into the surrounding area). Sorry, power went out briefly, so I posted previously quickly, but wanted to add this question too.
-
Ok, I'll render the sequence tonight again and separate the layers to "BloomGlare" + "VirtualBeauty with no bloom&glare"
I'll also attach tomorrow two consecutive frames rendered as CXR.
Yes - I'm using the new light solver (all render settings are at default)
I know that green is naturally more dark than the white - but I gave the green light more self illumination than the white so it is balanced. Also it only happens in the green lights in that area - other green lights with the same material are fine
-
Just a note, not the new light solver, but the new High Quality Image Filtering :) The new light solver should have no impact on this situation, but the expanded pixel range of the new High Quality Image Filtering might.
-
Yes - green lights in that area flicker, but the white ones do not. Green lights in another area don't flicker. This is what leads me to think it is to do with the width/size of the lines as the camera moves, and the reduced overall intensity of that color, which is why I'd try lowering the Threshold in the bloom and glare, as if it so happens that some pixels are dipping above and below the current threshold due to anti-aliasing/filtering, this could stop the flicker by making them "always on" as far as B&G is concerned. And yep, the best way to check the final intensity would be the right click to inspect the pixel value in the render (hence the other request for two CXRs to do just that kind of peeking!)
-
Yes, High quality filtering is "on"
-
Yes, High quality filtering is "on"
So I would try with it on, and lower threshold, and try with it off and the same threshold as currently, see if either changes the results :)
-
If you look closely, you can see that some other colours also flickering, just not as intesively as green buttons.
-
First - I attach the animation as 2 separate layers.
I tried a few things but nothing helps:
1. I changed the threshold of the bloom&glare (higher\lower)
2. I changed the intensity of the green illumination.
3. I changed from high quality filtering to tent. Tried it with width px of 2, and 1.
Nothing helps...
I can't upload the CXR files since they are huge
-
You can see how green parts are shimmering even without B&G. I don't think there's much you can do about that, other than to render at double resolution and then downsample, but of course that's highly impractical with animation. Alternatively, you could search for third party B&G solution, which would have temporal antialiasing option. Maybe arionFX could do that?
-
Yes, you're right, the green parts are shimmering without B&G...
I don't care so much about the B&G - This is a project for myself to practice things...But I do care about this shimmering in the lights
What can cause them to not render smooth ? maybe it's because I'm rendering with camera MB ?
-
Video (or picture) has limited resolution and when very thin object is travelling through screen, it may occupy different number of pixel lines. In one frame it might be displayed as two full lines and in the next one it might be smeared over three lines. The thinner the object is, the more pronounced shimmering will be. Better filtering algorithm may help to reduce the effect, but ultimately, in extreme cases like yours, there's only so much it can do. Rendering at bigger resolution, would be the best option here, because it would affect the root of the problem. If you were using time limit for your animation, then i'd suggest to leave time limit the same and double the resolution - rendered image will be much noisier, but when you'll downsample to half rez, it should contain roughly the same noise level as original frames, but AA will be much better. You can also use blurrier image filtering with bigger radius, because downsampling will make your picture much sharper and generally you don't want too much sharpness in animation.