Wrong render with HDRi when there Sun lamp with strength=0 #48790

New Issue

YAFU · 2016-07-05T05:22:33+02:00

YAFU commented

2016-07-05 05:22:33 +02:00

System Information
Kubuntu Linux 14.04, GTX 960

Blender Version
Broken: from master, 2.77.1 39ae324
Worked: 2.77a

Short description of error
Wrong render with HDRi when there Sun lamp in the scene with strength=0

Exact steps for others to reproduce the error
Scene: hdri_sun0.blend
HDRi: https://hdrihaven.com/hdri.php?hdri=sisulu&dl=yes
Open the scene. Load the HDRi (it is not packed). Render.

**System Information** Kubuntu Linux 14.04, GTX 960 **Blender Version** Broken: from master, 2.77.1 39ae324 Worked: 2.77a **Short description of error** Wrong render with HDRi when there Sun lamp in the scene with strength=0 ![untitled.jpg](https://archive.blender.org/developer/F319519/untitled.jpg) **Exact steps for others to reproduce the error** Scene: [hdri_sun0.blend](https://archive.blender.org/developer/F319518/hdri_sun0.blend) HDRi: https://hdrihaven.com/hdri.php?hdri=sisulu&dl=yes Open the scene. Load the HDRi (it is not packed). Render.

YAFU commented

2016-07-05 05:22:33 +02:00

Changed status to: 'Open'

YAFU commented

2016-07-05 05:22:33 +02:00

Added subscriber: @YAFU

YAFU commented

2016-07-05 05:34:02 +02:00

Sorry, this happens with any type of lamp with strength=0

Campbell Barton commented

2016-07-05 06:00:57 +02:00

Added subscriber: @ideasman42

Campbell Barton commented

2016-07-05 06:00:57 +02:00

Renders black when the strength is 0.0, both for 2.77a and master (9269574089a742130f02c0a1184a19d94f0e665d)

Renders black when the strength is 0.0, both for 2.77a and master (`9269574089a742130f02c0a1184a19d94f0e665d`)

YAFU commented

2016-07-05 13:19:55 +02:00

Hi.
On my machine the render looks good with 2.77a (abf6f08):

Hi. On my machine the render looks good with 2.77a (abf6f08): ![untitled_1.jpg](https://archive.blender.org/developer/F319550/untitled_1.jpg)

Sergey Sharybin commented

2016-07-05 17:38:47 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2016-07-05 17:38:47 +02:00

The file has Strength of 1.0. Setting it to 0.0 makes everything black (as expected).

What are the exact steps reproducing the issue?
What is exact issue anyway?
Does it happen with CPU?
Does it happen with latest builds from builder.blender.org?

The file has `Strength` of 1.0. Setting it to 0.0 makes everything black (as expected). - What are the _exact_ steps reproducing the issue? - What is _exact_ issue anyway? - Does it happen with CPU? - Does it happen with latest builds from builder.blender.org?

YAFU commented

2016-07-05 18:02:23 +02:00

Perhaps I have not been clear here. Apparently you refer to World (HDRi environment texture) strength. You do not touch that value in the scene, you leave that value to 1. With "strength=0" I am referring to the lamp selected by default when you open the scene. You just open the scene and render in Belnder from master (Do not forget to load the HDRi). Did you not get a resulting image like the first image I've shared?. I think it should look like the second image I obtained in Blender 2.77a.
I know, there is no logical reason to put there a lamp with strenght=0. But anyway I do not see any reason to get a resulting image like the obtained from master (first image).
EDIT:
Regarding whether this occurs in CPU/GPU, master/buildbot:

Buildbot b27322e :
GPU: That diagonal division is very noticeable
CPU: That diagonal division is a bit less noticeable than GPU, but still noticeable.
Compiled from Master 39ae324 :
GPU: That diagonal division is very noticeable
CPU: That diagonal division barely noticeable, mainly it is more noticeable when it begins to render the first samples.

Perhaps I have not been clear here. Apparently you refer to World (HDRi environment texture) strength. You do not touch that value in the scene, you leave that value to 1. With "strength=0" I am referring to the lamp selected by default when you open the scene. You just open the scene and render in Belnder from master (Do not forget to load the HDRi). Did you not get a resulting image like the first image I've shared?. I think it should look like the second image I obtained in Blender 2.77a. I know, there is no logical reason to put there a lamp with strenght=0. But anyway I do not see any reason to get a resulting image like the obtained from master (first image). EDIT: Regarding whether this occurs in CPU/GPU, master/buildbot: - Buildbot b27322e : GPU: That diagonal division is very noticeable CPU: That diagonal division is a bit less noticeable than GPU, but still noticeable. - Compiled from Master 39ae324 : GPU: That diagonal division is very noticeable CPU: That diagonal division barely noticeable, mainly it is more noticeable when it begins to render the first samples.

Bastien Montagne commented

2016-07-15 17:06:44 +02:00

Added subscribers: @ThomasDinges, @mont29

Bastien Montagne commented

2016-07-15 17:06:44 +02:00

Can’t confirm this with CPU rendering indeed, don’t have GPU one here… But imho you are stressing system out of expected 'domain', what’s the point in testing something with zero-strength lamp?

Anyway, @Sergey or @ThomasDinges, can you reproduce the issue now with specified steps?

Can’t confirm this with CPU rendering indeed, don’t have GPU one here… But imho you are stressing system out of expected 'domain', what’s the point in testing something with zero-strength lamp? Anyway, @Sergey or @ThomasDinges, can you reproduce the issue now with specified steps?

YAFU commented

2016-07-15 18:16:02 +02:00

Hello Bastien!

In #48790#381753, @mont29 wrote:
what’s the point in testing something with zero-strength lamp?

Oh no. No point at all.
I just was testing another scene where I was working, and I wanted to see the render without the influence of the Sun lamp. As I usually find the outliner a bit complicated, I just decided to put Sun strength=0, then I found the problem . Then I discovered that this did not occur in previous versions of Blender, and then build a small scene and report just in case.
I do not know, maybe in a very large and complex scene a little experienced artist (like me) could be left forgotten there a lamp with strength=0. But I guess it will not be very common cases.

By the way, the problem is still present in my machine and last buildbot.

Hello Bastien! > In #48790#381753, @mont29 wrote: > what’s the point in testing something with zero-strength lamp? Oh no. No point at all. I just was testing another scene where I was working, and I wanted to see the render without the influence of the Sun lamp. As I usually find the outliner a bit complicated, I just decided to put Sun strength=0, then I found the problem . Then I discovered that this did not occur in previous versions of Blender, and then build a small scene and report just in case. I do not know, maybe in a very large and complex scene a little experienced artist (like me) could be left forgotten there a lamp with strength=0. But I guess it will not be very common cases. By the way, the problem is still present in my machine and last buildbot.

Sergey Sharybin self-assigned this 2016-07-27 11:35:00 +02:00

Sergey Sharybin commented

2016-07-27 11:35:00 +02:00

@YAFU, with the detailed explanation now i see what you mean :) Indeed see the bug here. Investigating...

Sergey Sharybin removed their assignment 2016-07-27 14:56:10 +02:00

Brecht Van Lommel was assigned by Sergey Sharybin

2016-07-27 14:56:10 +02:00

Sergey Sharybin commented

2016-07-27 14:56:10 +02:00

Added subscriber: @brecht

Sergey Sharybin commented

2016-07-27 14:56:10 +02:00

@brecht, apparently caused by 42aec3b. Setting strength is required to make it so you're leaving with lamp shader with just output node. You can also simply remove any connection from lamp shader outputs to see the same issue.

@brecht, apparently caused by 42aec3b. Setting strength is required to make it so you're leaving with lamp shader with just output node. You can also simply remove any connection from lamp shader outputs to see the same issue.

blender-admin commented

2016-07-27 23:09:38 +02:00

This issue was referenced by blender/cycles@1f49c7bc43

This issue was referenced by blender/cycles@1f49c7bc43eea07f979145d7d97efe60749d96f7

blender-admin commented

2016-07-27 23:09:38 +02:00

This issue was referenced by b645e7081d

This issue was referenced by b645e7081d2bcc92108d4f6b3a97f84b20855650

Brecht Van Lommel commented

2016-07-27 23:13:39 +02:00

The issue was in earlier code to disable lights, but better constant folding made it apparent.

Brecht Van Lommel commented

2016-07-27 23:13:45 +02:00

Changed status from 'Open' to: 'Resolved'

Brecht Van Lommel closed this issue

2016-07-27 23:13:45 +02:00

Sergey Sharybin commented

2016-07-28 09:22:30 +02:00

@brecht, interesting. Because i was unable to reproduce issue with a revision previous to node refactor. Could have been some red-herring or just some unrelated changes made it visible. Thanks for the fix!

YAFU commented

2016-07-28 16:57:29 +02:00

Working well now.
Thanks.

Working well now. Thanks.

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Wrong render with HDRi when there Sun lamp with strength=0 #48790