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Maniphest T73834

Rendering a scene without light: result is not completely black
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Description

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce RTX 2070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19

Blender Version
Broken: version: 2.83 (sub 3), branch: master, commit date: 2020-02-14 23:40, hash: rB92a56bbe6a98
Worked: v 2.82

Short description of error
Rendering a scene without light results in a render, that is not completely black, but shows a dark noise.
This happens with Eevee, Cycles CUDA and Cycles OptiX

The dark noise not only appears in the Viewport but also when rendering the scene.

I would expect that the background of the scene is completely black (#000000), however it shows only a dark noise.

Attached is a comparison picture of the view after the described steps in v2.82 and v2.83

Exact steps for others to reproduce the error

  1. Begin with default startup file
  2. Switch "Viewport Shading" to "Display Render Preview"
  3. "World properties" -> "Surface" -> Set "Strength" to 0.000

Thank you for having a look into this issue.

Related Objects

Event Timeline

Gaddhi (Gaddhi) created this task.Feb 15 2020, 12:37 PM
Pasang Bomjan (irex124) added a subscriber: Pasang Bomjan (irex124).Feb 15 2020, 2:01 PM

I can confirm. 2.83 used to work fine a few days ago.

William Reynish (billreynish) changed the task status from Needs Triage to Confirmed.Feb 15 2020, 4:17 PM
William Reynish (billreynish) assigned this task to Brecht Van Lommel (brecht).
William Reynish (billreynish) triaged this task as High priority.
William Reynish (billreynish) added a subscriber: William Reynish (billreynish).

Interestingly, I can confirm this while testing on macOS and Windows 10. Seems like a relatively high priority issue to me.

William Reynish (billreynish) changed the subtype of this task from "Report" to "Bug".Feb 15 2020, 4:22 PM
Brecht Van Lommel (brecht) reassigned this task from Brecht Van Lommel (brecht) to Clément Foucault (fclem).Feb 15 2020, 4:24 PM
Brecht Van Lommel (brecht) added a project: EEVEE & Viewport.
Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).

I'm assuming this is related to the recent color management refactor.

Gaddhi (Gaddhi) added a comment.Feb 15 2020, 5:35 PM

A few additional notes:

  • This issue happens not only for the background, but also for any objects, that have a black color.
  • When the intended color is not black, but slightly brighter, the noise is still there, but it is more difficult to notice.

After compiling and testing a few versions of blender, I was able to pinpoint the introduction of this issue.
This issue was not present in 58cdab8b9759dd59b55895f2f76b9624addbb324
but in the following commit 804e90b42d728ecb1073af8d0bae15a91b13a469

Clément Foucault (fclem) added a comment.Feb 15 2020, 8:51 PM

Likely to be fixed by D6850

Gaddhi (Gaddhi) added a comment.Feb 15 2020, 9:49 PM

@Clément Foucault (fclem) Thank you for pointing me to this patch. I will have a look at it.

Evan Wilson (EAW) added a subscriber: Evan Wilson (EAW).EditedFeb 15 2020, 10:03 PM

@Gaddhi (Gaddhi) Without the patch, I have found that a dithering value of around 0.1 works well for my use case, compared to the default 1 before. If you want pure black you have to set dithering to 0

Gaddhi (Gaddhi) added a comment.Feb 16 2020, 9:31 AM

I did apply D6850 to the current master-branch and tested it: It solved this problem.
@Evan Wilson (EAW) Thank you for pointing out this workaround.

Evan Wilson (EAW) merged a task: T73903: Grainy Viewport in 2.83 Alpha.Feb 17 2020, 3:51 AM
Evan Wilson (EAW) added a subscriber: Justin (blenux).
Clément Foucault (fclem) closed this task as Resolved.Feb 17 2020, 4:31 PM

Fixed by 852cdd476b55

Gaddhi (Gaddhi) added a comment.Feb 17 2020, 11:03 PM

@Clément Foucault (fclem) Thank you for the extremely fast resolution of this issue. I can no longer reproduce this problem in the daily build of February 17, 18:25:57.