Author Topic: dubcats secret little hideout  (Read 110220 times)

2018-10-02, 19:51:27
Reply #315

Fluss

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assumption 1: Even if it does not make a huge difference, it has been proven that rendering in ACEScg (which is more or less similar to REC.2020) will be closer to a ground truth full spectral rendering. Anders Langland discuss the subject in this article: https://www.colour-science.org/anders-langlands/

assumption 2: just to clarify, ACES color spaces are based on the RGB color-additive model (i.e colors are encoded with R,G and B chromaticities). RGB is a color model like XYZ, HSV, LaB etc.. By RGB, you mean sRGB which is a color space. Btw, you're absolutely not limiting the output by inputting converted data from a smaller gamut color space. As the gamut is smaller, you'll have a smaller subset of possible colors, resulting in a loss of color accuracy for representing the real world data. But you're not limiting anything here.

2018-10-03, 12:19:37
Reply #316

IsmaeL

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Interesting stuff here as always.

About the howl ACES debate, is there any significant advantage we would get from using ACES. This all sounds very complicated and yet I don't really se a big change.

To be honest, I would much rather prefer a wider color space inside of Max. Getting a color managed 3d application like Maya or Blender, I think even Cinema is color managed (not sure).
This would help when inputting real life colors and if we are talking about REC 2020, we could use that color space directly to work in and output images.

The second question is about the ACES compression dubcat uses, I know I read an article years ago about it. Is it somehow related to the ACEScg workflow?? Can we use it independent?? And why should we use it at all?

Finally, what is up with Lambert model for diffuse?? What is Vray using? And how would a different model be better??

BTW. Love that Canon EOS LUT
Falling in love with Corona

2018-10-03, 13:03:45
Reply #317

Juraj Talcik

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One idea behind asking for ACES was that it would be one fly swatted together to get both color management and some VFX utility. (And easy way to use their nice filmic tonemapper in correct way).

Corona is already using wide-gamut for internal computation but both input and output are limited to sRGB and yet unmanaged.
3dsMax is not getting color management any soon it seems (unlike Maya), so at least Corona should step up.

Vray uses Lambert by default but gives you option to mix it with Oren-Nayar (it's hidden behind the "diffuse roughness" setting). Issue with lambert is that nothing really looks like it and it's not flexible to adjust in any way (unlike other models).
Simulating rough paint for example with CoronaMTL is currently done by the fresnel mixing GGX specular over Lambert diffuse. It doesn't mesh, it's not giving correct life-like result.
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2018-10-03, 15:54:20
Reply #318

IsmaeL

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Thanks Juraj, that clears things up.

So most of this could be resolved by getting a new VFB inside Corona.
One that does correct Filmic tonemapping and where you could preview an image in a certain color space.

Basically what you can already do in Vray when you load the ICC profile of your monitor.

As for Max, you have to request the color management and maybe we get lucky. Here is the link https://forums.autodesk.com/t5/3ds-max-ideas/implement-color-management-in-3ds-max-support-for-icc-luts-etc/idi-p/6790724

As for Lambert, I guess you should just stick to shiny surfaces XD
Falling in love with Corona

2018-10-03, 16:33:05
Reply #319

Basshunter

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As it's a scene referred workflow, it also allows you to preserve the whole dynamic range of your data all along the pipeline.

Would you mind to further explain the sentences "it's scene referred workflow" and "it allows to preserve the whole dynamic range of your data all along the pipeline"?
I have troubles understanding some technical expressions in English.

2018-10-03, 17:14:34
Reply #320

Fluss

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As it's a scene referred workflow, it also allows you to preserve the whole dynamic range of your data all along the pipeline.

Would you mind to further explain the sentences "it's scene referred workflow" and "it allows to preserve the whole dynamic range of your data all along the pipeline"?
I have troubles understanding some technical expressions in English.

You should look at this article which explains the core fundamentals of the ACES workflow in a quick and efficient way: http://shootdatapost.com/blog/2014/5/16/aces-in-10-minutes

2018-10-03, 17:16:39
Reply #321

Basshunter

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@Fluss. I'll check it out. Thanks

2018-10-17, 19:52:21
Reply #322

aldola

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Hi Dubcat, do you know some way to convert srgb images to LOG32?, i need to use some lut´s in this format

2018-10-28, 05:53:08
Reply #323

dubcat

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Hey!

I've blocked a few web sites this month so I don't have an excuse to procrastinate. I haven't read through the pages since my last post. I see the last post has a question for me. I just want you guys to know that I'm not ignoring you. I will respond when my "official" block is over. I just had to make this post on my phone.

I've been pushing for linear display value for "Value" since Corona Color Picker got introduced. Every time I talk to the Corona team, it seems that this request gets confused with something else, and I honestly don't understand what they confuse it for. I see the RC is almost ready and it results in me clenching to my pillow at night, crying inside.

Every studio/person out there that deal with real world reflectance values, knows that we need linear display for "Value".

This long time "bug" / feature request has now turned into a meme



This is the best way I can describe the current problem.



If you have to deal with real world paint values and scanned values, please let your voice be heard so we can get this quality of life feature implemented.
             ___
    _] [__|OO|
   (____|___|     https://www.twitch.tv/dubca7 / https://soundcloud.com/dubca7 ( ͡° ͜ʖ ͡°)

2018-10-28, 08:48:02
Reply #324

romullus

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I don't work with real world paint and scanned values, but i never understand why CCP shows value in sRGB only. I think it should respect sRGB switcher and show its values accordingly, just like red, green and blue channels does.
I'm not Corona Team member. Everything i say, is my personal opinion only.

2018-10-28, 13:34:47
Reply #325

Juraj Talcik

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Yup, this should be super easy and obvious fix. It's already working on RGB channels, so why not the value ? It absolutely needs to be consistent.
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2018-10-29, 09:32:26
Reply #326

IsmaeL

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Definitely annoying. Seams kind of silly that this hasn't been fixed yet.

So where should we post about this, is it a bug or should we go to the feature request??
So many threads around here.
Falling in love with Corona

2018-10-29, 11:26:12
Reply #327

Juraj Talcik

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I don't know myself, there isn't clear feedback anywhere. Ideally both.
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2018-10-29, 12:56:38
Reply #328

Jpjapers

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I don't know myself, there isn't clear feedback anywhere. Ideally both.

Perhapt there should be a stickied SAT Thread (Small annoying things)

2018-10-30, 09:36:56
Reply #329

IsmaeL

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Perhapt there should be a stickied SAT Thread (Small annoying things)

That is a very good idea
Falling in love with Corona