Flickering

[petoboso]

Hi, I think corona needs something like vrays "subpixell mapping".
In scenes with small lights and many sharp reflections is imposible remove noise in reasonaible time.
I have tested simple scene with1 light and some glass. rendertime is more than enough for that simple scene and i didn't find the way to resolve it.


scene is in the attachment

[cecofuli]

GI/AA = 32?
MSI = 5?
LSM 0.2?

Try

GI/AA = 8-6
MSI = 20
LSM 12
Tint width = 2

[Chakib]

Did you try the default setting before changing all these values?

[Ondra]

nope, I'm not doing subpixel mapping, sorry

[Ludvik Koutny]

Subpixel mapping is a  nonsense. Even Vlado himself suggests not to use it. Revert settings to defaults, then decrease GI/AA balance to 4 and give it another try. Also try to increase Highlight Compression.

[juang3d]

Let me ask another thing.

Why are you rendering frames based on time? This will give you different noise amount in every frames, you should be rendering based on passes to achieve an uniform noise result.

Cheers.

[petoboso]

Thanks, now  im testing it by your suggestions, today i will put here something.
to Rawalanche: i know, subpixel mapping is "non realistic" feature and sometimes ruin quality of details,  but without it a have to hugely increase AA, what mean very long rendertime.

[Ludvik Koutny]

Thanks, now  im testing it by your suggestions, today i will put here something.
to Rawalanche: i know, subpixel mapping is "non realistic" feature and sometimes ruin quality of details,  but without it a have to hugely increase AA, what mean very long rendertime.

That's how Vray works...  not all renderers.

[petoboso]

So finally:
Default setting:


after some setting:

its better but still not clear, im testing this scenario because i did few animation inside dishwasher with vray and i would like use corona in future but im afraid of rendertime in this type of scenes.

[Ludvik Koutny]

Vray has by default a lot lower trace depth. Like 6 or something. You could try to do the same.

[petoboso]

minimal 12-16 is necessary
only way is decrease max sample intensity, but then i lose lot of reflections

[Ludvik Koutny]

Can you do Vray render for comparison? With same trace depth and with reflect on back side enabled? (Corona does not skip internal reflections by default) And of course with subpixel mapping disabled, because subpixel mapping is something like more aggressive form of max sample intensity.

[petoboso]

vray without subpix is disaster. (that camera shake is some bug in max2014)

 
this is with subpix enabled- many reflection is missing, but nearly without noise


if i compare without Subpix then is Corona clearly better than vray but because of rendertime i have to use vray +subpix
i will try with lower maxsample intensity today

[maru]

In Vray with subpixel mapping, the reflections are clearly dimmer. Maybe in Corona you could:

-lower glass's reflectivity

or

-make the light less intensive and walls brighter

[Ludvik Koutny]

So why do you complain that with lowering MSI you lose reflection detail, when with subpixel mapping you lose a LOT more reflection detail? Simply lower max sample intensity to fairly small value (like 5-10). You can also try to raise GI/AA balance to get more refraction rays. But slightly. I think for this scene, value of 8 will provide a good balance. And you can also see that Vray render is also missing internal reflections, you probably forgot to turn them on which makes situation for Vray even easier.