Author Topic: Tonemapping playground!  (Read 18895 times)

2022-04-25, 02:58:31
Reply #45

VASLAVO

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Hi guys, not 100% related to tone mapping but most of the time when i try to copy the current VFB on interactive rendering the max gets frozen and hangs, computer spec: AMD threadripper 3090x, 256 gb ram, video card 3080TI

2022-04-25, 10:06:29
Reply #46

GeorgeK

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Quote
It doesn't necessarily happen only in 3dsmax, also outside of it, with CIE directly.
Does this also solve the whole post problem when opening .cxr independently in CIE?
Sorry for my english.

We didn't encounter any issues with CIE yet so I am unaware if it does affect it, also the aforementioned solution doesn't seem to work for some so it's still under investigation.
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2022-04-27, 19:15:26
Reply #47

dj_buckley

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Hey guys.  Love the new tonemapping so far.  ACES OT and then season to taste with the tone curve seems to be the one for me.  ACES OT clips the highlights just a bit too much for my liking but that can be easily brought back with the Tone Curve operator.  Lovely stuff.

One thing that would be nice would be to have a histogram visible in the framebuffer without needing to add a curves operator and then click another button to open the curves window.  I'm not talking about something i can adjust, just a visual representation of the histogram that reacts to any changes I make in the tone curve operator for example.

Also I've had a couple of instances where saving a tone mapping config and then loading it again, results in a completely random stack of operators being loaded.

Just to add to this it appears some of the operators affect visible HDRI backgrounds a little to strongly, for example, if there is visible vignetting in the HDRI, adjusting the shadows of the Tone Curver operator seems to affect the vignetting and even some midtone, whilst the vignetting is technically a shadow, it's nowhere near the 'darkest' parts of the image.
« Last Edit: 2022-04-28, 09:52:01 by dj_buckley »

2022-05-02, 16:40:17
Reply #48

rowmanns

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Hey guys.  Love the new tonemapping so far.  ACES OT and then season to taste with the tone curve seems to be the one for me.  ACES OT clips the highlights just a bit too much for my liking but that can be easily brought back with the Tone Curve operator.  Lovely stuff.

One thing that would be nice would be to have a histogram visible in the framebuffer without needing to add a curves operator and then click another button to open the curves window.  I'm not talking about something i can adjust, just a visual representation of the histogram that reacts to any changes I make in the tone curve operator for example.

Also I've had a couple of instances where saving a tone mapping config and then loading it again, results in a completely random stack of operators being loaded.

Just to add to this it appears some of the operators affect visible HDRI backgrounds a little to strongly, for example, if there is visible vignetting in the HDRI, adjusting the shadows of the Tone Curver operator seems to affect the vignetting and even some midtone, whilst the vignetting is technically a shadow, it's nowhere near the 'darkest' parts of the image.
Hi,

We can log those as feature requests.

Regarding the bug of saving and loading the tonemapping config. Do you have a scene where this is reproduceable?

If so I'd like to take a look.

Thanks,

Rowan
Please read this before reporting bugs: How to report issues to us!
Send me your scene!

2022-05-03, 10:27:03
Reply #49

dj_buckley

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Unfortunately not, but I saved a config in one scene, then tried to load it in a different scene and thats when the random stack loaded.

2022-05-31, 18:18:12
Reply #50

piotrus3333

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one thing about ACES OT - is the drop of one stop of exposure really necessary? I know it matches ACES OCIO lin to srgb transform but this does not make any sense now.

edit:
https://polyhaven.com/a/brown_photostudio_02

« Last Edit: 2022-05-31, 22:52:46 by piotrus3333 »
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2022-05-31, 18:51:05
Reply #51

piotrus3333

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and custom LUT in CIE:
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2022-05-31, 21:45:32
Reply #52

Dionysios.TS

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one thing about ACES OT - is the drop of one stop of exposure really necessary? I know it matches ACES OCIO lin to srgb transform but this does not make any sense now.

Thanks for mentioning it, I've notice that too.

2022-06-03, 17:34:46
Reply #53

maru

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We have this logged, and some of the possible outcomes include:
- making the exposure consistent regardless if ACES OT is on/off
- explaining why it should not be done

We will definitely share some updates on this ASAP.

(Internal ID=909121934)
Marcin Miodek | chaos-corona.com
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2022-06-03, 18:13:33
Reply #54

Dionysios.TS

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We have this logged, and some of the possible outcomes include:
- making the exposure consistent regardless if ACES OT is on/off
- explaining why it should not be done

We will definitely share some updates on this ASAP.

(Internal ID=909121934)

Thanks for the updates and personally I am looking forward for your news!

Have a nice weekend,

Dionysios -

2022-06-04, 11:20:45
Reply #55

piotrus3333

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while I was waiting for some clarification I asked the same on YT. Then I deleted the comment as I realised the forum is the right place for it - but I got a reply anyway. As it is not visible on YT I will share it here as it explains the logic behind ACES OT:

“ There certainly is - two reasons in fact. One is that to change the exposure here could adjust sampling in Corona and the amount of noise, and the second is to ensure that the ACES OT is an industry standard (which does not include any exposure compensations in it). In other words, "if you saved the raw image in Corona, loaded it in e.g. Nuke (or any other package which supports ACES workflow), set up the color science properly and displayed it via ACES pipeline, it would look nearly identical as the output you see in Corona with ACES OT enabled." - while if we added exposure compensation as an additional step in the ACES OT itself, this would no longer be true (and it would no longer be ACES OT, but "ACES OT + Exposure). Last, it is not expected that ACES OT be toggled on or off really; it is expected it is either chosen to be part of your final workflow or not, thus the Simple or Photographic exposure would be set accordingly for it either on or off and there would be no inconvenience there then. If you did have a scene that for some reason mixes both workflows, you could just save configs or set up different cameras with their own unique tone mapping stacks, and in either cases ACES OT would be enabled or disabled and appropriate exposure set to match it. Hope that helps! Tom”
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2022-06-06, 11:26:45
Reply #56

maru

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one thing about ACES OT - is the drop of one stop of exposure really necessary? I know it matches ACES OCIO lin to srgb transform but this does not make any sense now.

Thanks for mentioning it, I've notice that too.

@Piotrus3333 @Dionysios.TS - could you please explain in what exact situations the current behavior is a problem for you? Why would you like to have this changed? (I do have my own ideas, but wanted to hear it from you as a part of research what would be the best solution here)

Marcin Miodek | chaos-corona.com
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2022-06-06, 13:19:09
Reply #57

piotrus3333

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@Piotrus3333 @Dionysios.TS - could you please explain in what exact situations the current behavior is a problem for you? Why would you like to have this changed? (I do have my own ideas, but wanted to hear it from you as a part of research what would be the best solution here)

it's not a problem at all if you know what is happening under the hood. but ACES OT is there by default, ready to be turned on and in its current state it is hardly the "one click tone mapping" that users were expecting.
just copy the AMPAS curve from V-Ray I guess and make this one default. or remove ACES OT from default layer stack and add Corona ACES filmic to preset list (ACES OT + one stop of exposure).
average Corona user would appreciate much more an easy match to V-Ray's output than an easy match to material within colour managed compositing pipeline...

quick comparison of "one click" tone mapping options in Corona:
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2022-06-06, 13:29:50
Reply #58

maru

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Can you explain what exactly those images are showing? Which operators are used in which case?
Also, could you upload them one by one instead of a single image so that it would be easier to switch between them and compare?
Marcin Miodek | chaos-corona.com
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2022-06-06, 14:12:07
Reply #59

piotrus3333

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Can you explain what exactly those images are showing? Which operators are used in which case?
Also, could you upload them one by one instead of a single image so that it would be easier to switch between them and compare?

I posted more detailed comparison in one of the previous posts. this one just shows what difference one lost stop of exposure makes. just quick glance and pick the best looking one. three sort of "one click" solutions: Corona's Filmic, ACES OT and simulated AMPAS. details below:

edit: LUT https://forum.corona-renderer.com/index.php?topic=28156.msg192497#msg192497

« Last Edit: 2022-06-06, 14:17:31 by piotrus3333 »
Marcin Piotrowski
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