Texture painting uses wrong values from picker #77736

New Issue

Sam Van Hulle · 2020-06-10T20:28:50+02:00

Sam Van Hulle commented

2020-06-10 20:28:50 +02:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19

Blender Version
Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: 211b6c29f7

Short description of error
Colour picking while painting in the Image Editor commits the linear RGB values as colour managed - which causes their linear counterparts to differ from what we chose.
While this is desirable for colour channels like Base Color, SSS, and Emission, it's the polar opposite of what we need for data channels like Roughness, where we know exactly what linear values we want, and no conversion should ever happen.
It's as simple as placing a dropdown in the colour picker, offering us the choice between linear and display space.

Exact steps for others to reproduce the error

Create a 32-bit float image data block in the Image Editor, set its mode to Paint.
Since we're painting a 1D data channel, pick a grayscale 'colour' of 0.5
Paint on the canvas. The Image Editor now assumes we want to store what we see.
Switch the Image Editor mode from Paint to View and hold RMB over the gray pixels.
Their colour managed values are 0.5, but their linear values are now 0.214

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19 **Blender Version** Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: `211b6c29f7` **Short description of error** Colour picking while painting in the Image Editor commits the *linear* RGB values as *colour managed* - which causes their linear counterparts to differ from what we chose. While this is desirable for colour channels like Base Color, SSS, and Emission, it's the polar opposite of what we need for data channels like Roughness, where we know exactly what linear values we want, and no conversion should ever happen. It's as simple as placing a dropdown in the colour picker, offering us the choice between linear and display space. ![Untitled.png](https://archive.blender.org/developer/F8606526/Untitled.png) **Exact steps for others to reproduce the error** 1. Create a 32-bit float image data block in the Image Editor, set its mode to Paint. 1. Since we're painting a 1D data channel, pick a grayscale 'colour' of 0.5 1. Paint on the canvas. The Image Editor now assumes we want to store what we see. 1. Switch the Image Editor mode from Paint to View and hold RMB over the gray pixels. 1. Their colour managed values are 0.5, but their linear values are now 0.214

Sam Van Hulle commented

2020-06-10 20:28:50 +02:00

Added subscriber: @frameshift

blender-admin commented

2020-06-10 20:28:50 +02:00

#99082 was marked as duplicate of this issue

blender-admin commented

2020-06-10 20:28:50 +02:00

#88646 was marked as duplicate of this issue

Brecht Van Lommel commented

2020-06-11 19:45:34 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2020-06-11 19:45:34 +02:00

Changed status from 'Needs Triage' to: 'Archived'

Brecht Van Lommel closed this issue

2020-06-11 19:45:34 +02:00

Brecht Van Lommel self-assigned this 2020-06-11 19:45:34 +02:00

Brecht Van Lommel commented

2020-06-11 19:45:34 +02:00

This kind of suggestion is outside the scope of the bug tracker:
https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests

This kind of suggestion is outside the scope of the bug tracker: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests

Sam Van Hulle commented

2020-06-12 21:50:17 +02:00

@brecht I disagree. Feature requests are scoped to obviously missing things that generally would be nice to have - hence that page's reference to Right-Click Select etc.
The only feature request I see here is that mention of a dropdown - which is a mere suggestion on how to fix the error. It's the error I'm reporting - how exactly it gets solved is up to you.
The error at hand is that Blender only allows colour picking in one space. This results in output that's unexpectedly wrong in many cases. To the vast majority of users, that will look like nothing but a bug.

It just dawned on me that it's probably not limited to texture painting: everywhere the colour picker is used, display space coordinates are returned, right? That would make this probably better discussed in #72424.

But I would never call something this essential a feature request.

@brecht I disagree. Feature requests are scoped to obviously missing things that generally would be nice to have - hence that page's reference to Right-Click Select etc. The only feature request I see here is that mention of a dropdown - which is a mere suggestion on how to fix the error. It's the *error* I'm reporting - how exactly it gets solved is up to you. The error at hand is that Blender only allows colour picking in one space. This results in output that's unexpectedly wrong in many cases. To the vast majority of users, that will look like nothing but a bug. It just dawned on me that it's probably not limited to texture painting: everywhere the colour picker is used, display space coordinates are returned, right? That would make this probably better discussed in #72424. But I would never call something this essential a feature request.

Omar Emara commented

2022-02-10 09:28:44 +01:00

Added subscribers: @JamellMoore, @OmarEmaraDev

Omar Emara commented

2022-06-22 10:18:24 +02:00

Added subscriber: @Harti

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Texture painting uses wrong values from picker #77736