Blown highlights cause flicker

[yanligoth]

How do you remove flicker from over blown highlight?

No matter what settings I use, unless I eliminate it completely, the animation flickers every frame, what am I missing?

I am using brute force gi with 0.005 noise.

Edited June 23, 2018 by yanligoth

[Francisco Penaloza]

We will really need more information regarding your scene, type of materials, lights, render settings.

Flickering can be caused by low sampling or interpolated GI.

IF you are using Brute force as first bounce what's your second bounce? Brute force too?

if so then it could be still low samples or too bright areas. Are you using come color mapping? have you tried the clamping option?

are you using too high values for your lights?

Your materials have bright tones such as 10% 0Saturated colors?

[yanligoth]

I am using VRayIES light, 5000 intensity, 128 subdivs.

material, a very simple VRayMtl with mix map curve for refl. gloss, mix amount defined by a bitmap.

I've tried using brute force/light cache, brute force/brute force, doesn't help.

I'm not using color mapping/color clamp, tried, didn't help.

Tried with VRay RT default settings + brute force/brute force

VRay Adv. subdivs 1/100, noise 0.005, min shading rate 24.

[yanligoth]

if anyone is willing to test, here is a test max scene, you can render frame 140/141, I appreciate.

https://www.dropbox.com/s/3wvicpwvd9jdurv/test.zip?dl=0

[Francisco Penaloza]

Can you post some screenshot of your scene, is very hard to give any input without knowing how you did set up your scene.

High overblow are caused by extreme intensity difference, this can be because of natural effect of exposure difference or too white materials or too bright lighting.

Also, they could be reflections of the environment, if you are using an HDRI to lit your scene, maybe the sun in that image is causing those very bright areas. in that case, using the clamping option will eliminate that also using color mapping. If it didn't work for you is because in your scene there is something else, or you did it wrong, but again is hard to tell without looking at your scene.

[yanligoth]

I've made a test scene. Unfortunately they don't want me to post links... so this is very cheasy but.. if you're willing to look at a scene, you can get it from dropbox, just enter /s/3wvicpwvd9jdurv/test.zip?dl=0 at the end of the host url. Try rendering frame 140-141 and you will see flicker.

[Francisco Penaloza]

OK I had time to check your scene.

The main problem is that there is too much light difference in that test scene, everything is black and your tripod is thin and highly glossy reflective, that is pushing the antialiasing very hard.

What I did to solve it was, increase the minimum antialising value, from 1-24 to 3-24, I also set up color mapping to Reinhard, burn to 0.4 and checked subpixel mapping, this is helping since your output is not large, (Larger image).

 

Now I took a look at your render settings, there were few changes here and there, but if you reset everything to default ( switch render engine to Scanline then switch back to V-Ray) and do the changes mentioned it should render fine.

The test attached is brute force in both bounces, but I got the same result with Brute force and Light cache.

 

BTW I also added some anisotropic value to your metal

 

https://www.dropbox.com/s/3jhka3hen049zou/tripod_Fix.mp4?dl=0

[yanligoth]

Mind sharing your settings file if you still have one?

I don't want to use color mapping, if possible I want to go linear.

 

I'm using 3 - 100 with noise 0.005, reduces flickering significantly, but still a bit left... "lock noise pattern" helps too, rendering takes ages though.

[Francisco Penaloza]

I can't share my file because yours is a student license 3D Max file, it won't open a full license file.

All the setting that I used are the ones I mentioned previously.

As mentioned your problem is that there is too much light difference between your shiny object and the black environment. That's why using a little clapping or color mapping will help you to control those over bright areas.

If you still want to go linear for some reason then you need to increase your minimum sampling, 6 or more. But obviously, this will increase your render time.

Having said that with my settings everything rendered pretty quickly on an 8 Cores Ryzen machine.

[yanligoth]

I ment v-ray setting file, but anyway, setting burn to 0.4 does help, however, brigtness difference from 1 - .4 is huge.

I could try to compensate for it a bit in post I guess.

[Francisco Penaloza]

I ment v-ray setting file, but anyway, setting burn to 0.4 does help, however, brigtness difference from 1 - .4 is huge.

I could try to compensate for it a bit in post I guess.

 

and that the way to go in this situation.

Don't be afraid to use post editing to enhance your images or videos.

All the videos and images that you get inspired or admire are enhanced after the render engine is done. From Bertrand to Pixar