Proposal: add a view transform for Khronos PBR Neutral Tone Mapper #118824

New Issue

Emmett-Lalish · 2024-02-27T23:29:23+01:00

Emmett-Lalish commented

2024-02-27 23:29:23 +01:00

@JulienDuroure recommended I submit a PR (I already have a working modified OCIO config), but I only seem to have permission to file an issue so far - and I'm likewise lacking some permissions on devtalk. Please let me know if there's a more appropriate forum for this discussion. FYI @brecht and @sergey, since I see your names under color management.

I developed a new tone mapping function, on behalf of Khronos, specifically to address the color accuracy needs of 3D e-commerce: getting PBR base colors to show through faithfully in the output render under grayscale lighting, without saturation loss, hue skews, or visual artifacts. It now has the official name Khronos PBR Neutral Tone Mapper, or PBR Neutral for short. For details, please see my writeup.

This is in no way a competitor to AgX or other filmic tone mappers; think of it instead as an improvement for anyone who currently disables tone mapping, what I believe is referred to as the Standard view transform in Blender. The addition of a PBR Neutral view transform would allow artists to easily see their PBR models in a color-neutral way without blown-out highlights, that can exactly match common end-point renderers that have adopted this new standard, e.g. Three.js and Filament.

Thank you for your consideration!

@JulienDuroure recommended I submit a PR (I already have a working modified [OCIO config](https://modelviewer.dev/examples/tone-mapping#ocio)), but I only seem to have permission to file an issue so far - and I'm likewise lacking some permissions on devtalk. Please let me know if there's a more appropriate forum for this discussion. FYI @brecht and @sergey, since I see your names under color management. I developed a new tone mapping function, on behalf of Khronos, specifically to address the color accuracy needs of 3D e-commerce: getting PBR base colors to show through faithfully in the output render under grayscale lighting, without saturation loss, hue skews, or visual artifacts. It now has the official name Khronos PBR Neutral Tone Mapper, or PBR Neutral for short. For details, please see my [writeup](https://modelviewer.dev/examples/tone-mapping). This is in no way a competitor to AgX or other filmic tone mappers; think of it instead as an improvement for anyone who currently disables tone mapping, what I believe is referred to as the Standard view transform in Blender. The addition of a PBR Neutral view transform would allow artists to easily see their PBR models in a color-neutral way without blown-out highlights, that can exactly match common end-point renderers that have adopted this new standard, e.g. [Three.js](https://github.com/mrdoob/three.js/pull/27668) and [Filament](https://github.com/google/filament/pull/7597). Thank you for your consideration!

👍 1

Emmett-Lalish added the

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label 2024-02-27 23:29:23 +01:00

Iliya Katushenock added this to the Video Sequencer project 2024-02-28 06:42:01 +01:00

Iliya Katushenock commented

2024-02-28 06:43:18 +01:00

recommended I submit a PR ... but I only seem to have permission to file an issue so far

Hi, please, follow this instructions: https://developer.blender.org/docs/handbook/contributing/

> recommended I submit a PR ... but I only seem to have permission to file an issue so far Hi, please, follow this instructions: https://developer.blender.org/docs/handbook/contributing/

Sergey Sharybin commented

2024-02-28 14:48:48 +01:00

@Emmett-Lalish That is a very nice write-up! I still only quickly skimmed through it though. I did some quick tests, and the mapper does produce interesting and more neutral results. Think it would be very nice to give it a push forward and move it to an actual PR, as it will simplify review and tests.

It would also be very nice to make the LUT reproducible. I see the CommerceToneMapping in the article, is it what you used to generate pbrNeutral.cube ? Is there some handy easy-ish-to-use script for it? :)

@Emmett-Lalish That is a very nice write-up! I still only quickly skimmed through it though. I did some quick tests, and the mapper does produce interesting and more neutral results. Think it would be very nice to give it a push forward and move it to an actual PR, as it will simplify review and tests. It would also be very nice to make the LUT reproducible. I see the `CommerceToneMapping` in the article, is it what you used to generate `pbrNeutral.cube` ? Is there some handy easy-ish-to-use script for it? :)

Brecht Van Lommel commented

2024-02-28 18:40:51 +01:00

I've bumped your trust level on devtalk.

Creating a fork and pull request should be possible with these steps:
https://developer.blender.org/docs/handbook/contributing/pull_requests/

I've bumped your trust level on devtalk. Creating a fork and pull request should be possible with these steps: https://developer.blender.org/docs/handbook/contributing/pull_requests/

❤️ 1

Emmett-Lalish commented

2024-02-28 21:00:21 +01:00

Thanks all! I'll go ahead and start a devtalk thread and a PR. @Sergey, yes the LUT is reproducible; simply run this script.

Thanks all! I'll go ahead and start a devtalk thread and a PR. @Sergey, yes the LUT is reproducible; simply run this [script](https://github.com/google/model-viewer/blob/master/packages/modelviewer.dev/examples/lut-writer.mjs).

Sergey Sharybin commented

2024-02-29 15:52:54 +01:00

@Emmett-Lalish Ah, lovely! Looking forward PR from you!

Emmett-Lalish referenced a pull request that will close this issue

2024-02-29 23:10:19 +01:00

Add Khronos PBR Neutral tone mapper #118936

Emmett-Lalish commented

2024-02-29 23:16:19 +01:00

Done! Please let me know if there's anywhere I should put or reference my LUT generation script. Likewise please point me to any documentation you'd like to see updated (does that happen in the same PR, or is that a different repo?).