Everything is darker after upgrading to Unity 6

[glacial otter]

Hi,
We had a project made in Unity 2022.3.62f2, and we have upgraded it to Unity 6. The colors became darker.
Now I've read many Unity Discussions post about it, and almost all of them mentioned that rebuilding lighting solved it. But not for us.
Rebuilding lighting finishes very quickly and seems to not have any impact.

Any idea?

its HDRP by the way

[timid knot]

First, investigate the cause.
Lighting is affected by:

• object shaders/materials
• light sources
• baked lighting or GI, lighting probes, etc...
• render pipeline settings, like shadows and light specific settings.
• possibly post processing effects.

Looking at the frame debugger can provide some clues where it goes wrong.

[glacial otter]

that would not be a 1 day work, that would be way longer

if I would need to use the frame debugger for this

[glacial otter]

and I doubt I'm the only one fighting with this

so there must be a general link or something about "how to setup visuals to get the same results you had"

[timid knot]

There isn't because it could be a hundred different things. Frame debugger is the fastest way.
You don't need a day for that. You can start getting insights in a few minutes.

[glacial otter]

and should I compare the results of the Frame Debuggers in both Unity 2022 and Unity 6?

or what should I look for?

@timid knot

[timid knot]

If you can compare to the proper data, that would be ideal. But even without it you can at least understand where it goes wrong(at what draw call).

[glacial otter]

@timid knot left one is Unity 6

[timid knot]

Just looking at the render passes list is not gonna help. You need to look at the individual draw calls in the passes. Start from the bottom. It would be ideal if you can find a draw call that looks the same on both versions, but that's not very likely. The last draw call in deferred lighting would make it clear if this is an issue with lighting or after that.

[glacial otter]

I can't see output image in any of the deferred lighting elements

[timid knot]

Might need to play with the visible range(a slider at the top)

[glacial otter]

no, I mean there's no output image in there

this is what I can see

the ForwardOpaque is the first one I can see the image

but that differs

[timid knot]

That's a compute shader. Is there no draw at the end of the deferred lighting pass?

[glacial otter]

these are all I can see

[timid knot]

Ok, what about the last command in Forward Opaque?

[glacial otter]

that's producing image, and they are different

@timid knot

[timid knot]

Is the difference similar to what you see in the actual scene/game?

[glacial otter]

nope

because post processing and other stuff is added

but its already differs in here

can this be the source of the issue?

@timid knot

[timid knot]

You should step up through the draw calls to see where that texture is rendered then

Or, actually...

Can you click that _Texture and show what it looks like?

[glacial otter]

this is just part of the end result

but you can already see it differs

[timid knot]

Does THIS texture differ between the versions?

[glacial otter]

the texture itself is not different

[timid knot]

This one #1443884661930594304 message ?
Are you sure??

Is this an actual texture asset? Or an intermediate render target?

[glacial otter]

I selected the same stages again, but now they have the same format, not like in this image...

[timid knot]

Are you sure you're looking at the image I am talking about?

There is not format or anything in it.

[glacial otter]

actual texture asset

but these images look the exact same way

[timid knot]

Aah, okay. That explains

[glacial otter]

in both Unity 6 and Unity 2022

[timid knot]

My best bet is that exposure values are different

[glacial otter]

hmm that's true

[timid knot]

It's likely calculated in one of the compute calls. Scroll through them and see if you can find one that references the texture for write.

[glacial otter]

that's the first compute stage

[timid knot]

I'm not sure if it's reading or writing here. But can you check all the other textures to see if they're identical?

[glacial otter]

all the other textures in the actual image? or in this stage?

I didn't change anything on the images

but this exposuretexture is really different

so this one really might be the difference

[timid knot]

in that compute deferred call

These. Are they all identical or are there some differences

[glacial otter]

GBufferTexture3 also differs

GbufferTexture0

[timid knot]

These look super weird... Does that resemble any geometry in the scene in any way?

[glacial otter]

others seems to be identical

[glacial otter]

there's a snow-like particle or shader or whatever VFX moving

[timid knot]

Hmm...
Perhaps try disabling that VFX and compare between versions again.

[glacial otter]

I disabled the gameobject itself, I even deleted it during runtime, but the result is the same

but its just the "snow"

so I guess the end result is influenced by the exposure texture

which is probably affecting the whole image

[timid knot]

The exposure is calculated from the brightness of the scene. If in the gbuffers the snow was standing out, it was a possible culprit.

[glacial otter]

ahhhhhh

okay

[timid knot]

I'd check the gbuffers again without the snow vfx

[glacial otter]

so then maybe the snow was cached?

and this is why it stayed in the frame calculation?

[glacial otter]

I told you it will take for hours

[timid knot]

There's no guarantee that it's the culprit. But eliminating possible culprits is gonna get us closer to the solution.

[glacial otter]

but should I eliminate that in the editor time?

while I stop the game?

and not during runtime?

[timid knot]

It should, yes

[glacial otter]

ok

[timid knot]

You don't need to build or even play the game(unless there's a considerable difference in the rendering behavior at runtime).

[glacial otter]

I know, I just didn't want to modify the scene itself

but then I will discard it

[glacial otter]

okay, now the GBufferTexture0 and 3 are clear

they are black

but still the exposure texture is different

[timid knot]

Ok, I can spot a few differences in textures between the two. Though it could be that the two on the right are packed in that texture on the left. Worth looking at this.

As for the gbuffers, they're likely not empty, just containing values at a lower range, so you can't spot any differences.

[glacial otter]

volumetric clouds are not even enabled

[timid knot]

Okay, then that can probably be ignored.

[glacial otter]

okay, then what?

[timid knot]

Check the gbuffers with reduced range. Not sure you can do that right in the frame debugger. Might need to open them in a separate image editor.

Did you compare all other textures in that compute command?

[glacial otter]

what are the gbuffers?

[timid knot]

Also, which command is that even? I don't see it selected in the hierarchy.

[glacial otter]

yes

everything else were identical

[glacial otter]

the bottom one

[timid knot]

Various data from your materials: normals, depth, metalic, albedo, emission and other values.

[glacial otter]

I compared the bottom Compute Deferred

[timid knot]

Is the exposure texture mentioned in any others?

[glacial otter]

yeah, in almost all of them

sorry

all of them

all of them has the exposureTexture

[timid knot]

Ok, then there's a big chance it's not where it's calculated at all

Compare the first command. Is the exposure different between the versions?

[glacial otter]

this is the earliest stage from the top I could find these

left is 2022, right is 6

[timid knot]

Interesting. So, there must be a difference in how the exposure is calculated. Or maybe a setting.

I'd check these doc pages to debug exposure differences:
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/Override-Exposure.html
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/test-debug-exposure.html

This might help find out if there is a specific object or material that makes the difference, or if it's the lighting in general.

[timid knot]

Also exposure settings on the volume: https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/understand-volumes.html
Make sure they match in both versions

[glacial otter]

these 3 exposure related settings are the exact same in both Unity

[timid knot]

I'm not sure if these are related to the actual exposure

[glacial otter]

Exposure Control is also used in both

[timid knot]

Ok, then use the debug features to investigate exposure.

[glacial otter]

and how can I use that effectively

[timid knot]

Compare the results between versions. See if there is a bigger difference in any specific area of the screen/coresponding to a specific object/renderer/materials in the scene.

[glacial otter]

left one is Unity 6, right one is 2022

@timid knot I have no idea what these histograms mean

[timid knot]

Should probably start with the Scene EV100 Values

[glacial otter]

unity 6 - unity 2022

@timid knot

[timid knot]

Don't look at the histogram. Look at the scene/game view. Are there areas that stand out/show more difference?

[glacial otter]

unity 6 - unity 2022

[timid knot]

Why is there such a difference in resolution?

[glacial otter]

because its so hard to scale the images of the editors the same way...

@timid knot

[timid knot]

What is the main source of light/brightness in that scene? What is that bright "cloud" around the "moon"?

Is it some kind of volumetric fog?

[glacial otter]

this is a texture

but there are also a volumetric fog added

and there are tons of other vfx

but those volumetric fog and vfx are not just around the sun

its all around the scene

[timid knot]

Can you try comparing with all the volumetric fog and other vfx disabled?

[glacial otter]

same

after stopping the game running in editor

[timid knot]

So at this point it's just that texture/image?

[glacial otter]

I removed vfx-es

fx-es

I removed volumetric fog

well, these are lot of textures

on top of each other

lot of disabled spotlight gameobjects

reflection probes

global volume

navmesh manager, fmod

etc. etc.

meshrenderers

[timid knot]

Hmm...
Let's start simple. Disable eveything in the scene. Add a default sphere and see if it looks the same between the versions. If it does, start enabling chunks of objects until there is a difference.

[glacial otter]

I kept the images, and camera, but removed everything else

if I remove the Global Volume, then exposure gets more similar than what it was in Unity 2022

but still stays different

[timid knot]

Yeah. Next try what I suggested.

[glacial otter]

I don't even need to put a sphere there

I don't know why is that yellow color in the left

[timid knot]

Great. Now take a look with frame debugger

[timid knot]

What does it look like outside the exposure debug mode btw?

[timid knot]

It's just an indication that the scene is bright(or at least brighter than on the right)

[timid knot]

Looks like sky settings to me

[opaque laurel]

hey uhh rq, this is the code channel

[glacial otter]

sorry

[timid knot]

Indeed. But at least it's a in a thread. Maybe mods can move it to rendering.

[opaque laurel]

threads can't be moved

[glacial otter]

please be patient. I will delete the whole post once I finished with it

[opaque laurel]

just saying, asking in #1390346776804069396 could probably get more relevant eyes on the issue, maybe even someone who's encountered it before

[glacial otter]

true

but I don't really want to start the whole discussion all over again

its already multiple hours went into this

[opaque laurel]

you can link back to this issue

(and also summarize what you'e already been through)

[glacial otter]

now I need to do something entirely else, but I will come back

[glacial otter]

@timid knot do you have any idea about what should I change?

skybox settings seem to be the same

[timid knot]

Can you show the sky ox settings? I think there might be in several places for hdrp(lighting tab, rp asset maybe somewhere else too).

[glacial otter]

never mind

I found the setting, HDRI Sky had an exposure compensation value

and when I cleared that value to be 0, then the empty scene changed to the original coloring

but if I discarded the scene

and I got back the original main menu

that looks the exact same

[timid knot]

Mm? So the issue is solved?
Or do you mean that resetting that setting doesn't help when switching between scenes?

[glacial otter]

no, the issue is not solved

at all

[glacial otter]

@timid knot I mean this gets solved

[glacial otter]

@timid knot but this won't

so I'm not sure anymore I can solve this

the coloring needs to be reset by an artist

because probably its get calculated fully differently in Unity 6

[timid knot]

No. There shouldn't be any difference. Same assets should produce the same image.
If the skybox is fixed, then you should next start reenavling objects in the scene until you start seeing difference again. At that point investigate the object that produces the difference.

[glacial otter]

well, even the bloom is different

it could take days or weeks to fix this

and I have zero idea which setting mean what

and the vignette is also different

but I can't find a setting to make them similar

[timid knot]

So if you disable post processing, it looks the same?

[glacial otter]

I think yes

if I disable post processing on both

but maybe the light around the sun is higher

[timid knot]

Looking at the black areas it still looks very different.
Did you not try what I suggested? Disable all the objects, then enable one by one(or groups of objects), until you start seeing differences.

[glacial otter]

I'm doing it, but I need to do other stuff in parallel. Checking it in a sec

@timid knot

all other stuff in scene is the camera and the actual visual pieces

[timid knot]

And if everything(aside from the camera) is disabled you see no differences?

[glacial otter]

I recognized if I delete the Global Volume, the Unity 2022 Scene view switches into grey background, but Unity 6 still shows sky

[timid knot]

Ah, I guess the skybox settings moved to lighting tab in unity 6.

[glacial otter]

BUT if I delete everything in Unity 2022, it also switches into the sky

[timid knot]

You could disable the skybox on Unity 6 to get a fair comparison.

[glacial otter]

and how to disable the skybox?

because there are multiple skybox setting categories

so I guess there are multiple skyboxes

in all project

[timid knot]

Mainly in the lighting settings. But can also be on the camera or the volume that you mentioned earlier.

[glacial otter]

@timid knot I disabled the skybox, and still the difference is here

[timid knot]

Where does it appear..?

[glacial otter]

what do you mean?

I replied to that comment

[timid knot]

Is that the first object where the difference appears?

[glacial otter]

in here

[timid knot]

If you disable it, there is no difference?

[glacial otter]

whatever I do, there is difference

in there

[timid knot]

So then you didn't do what I suggested..?

Disable everything. Start enabling objects one by one.

[glacial otter]

you suggested disabling skyboxes on both. I did that

[glacial otter]

even when I disable everything, that difference is there

[timid knot]

Show me.

There is a difference in an empty scene?

[timid knot]

I said like 10 times already, disable everything. Start enabling one by one... Or does it mean that there is only difference when all of the sprites are enabled??

[glacial otter]

okay, this is still a difference

[timid knot]

Great. Now, check both in the frame debugger

[glacial otter]

frame debugger is empty in both cases

[timid knot]

Add a camera.

[timid knot]

Show the camera settings.

[glacial otter]

@timid knot if I set both background type to None, then this grey rectangle appears in Unity6

@timid knot

@timid knot okay, apparently there's still some kind of skybox activated in Unity 6, because if I disable viewing Skybox in Scene view, then it shows the same as in Unity 2022

but then I have no idea how to fully disable that

there's no On-Off in Unity 6

In Unity 2022, at least there's the None option

never mind, I was an idiot

found it

[glacial otter]

@timid knot okay, tried to revert everything, because I'm not sure anymore I didn't fuck up something

and I can't set it back to how it worked before...

which asset stores the original skybox?

never mind

[glacial otter]

@timid knot okay, I have zero idea about what goes wrong... I can disable things until I can see the same on both screen, but then I can't re-enable them, because I always forget where the settings were ....

I don't understand what is HDRI sky... why one change in skybox is visible, why the other is not, etc.

why is there Sky type for example in 50 different places

[timid knot]

HDRI sky is a procedural skybox.

[timid knot]

There are several solutions for sky.

Seeing how your game is 2d, you probably don't need the sky at all. You should just set it to solid color and then compare both versions to make sure there's nothing else that creates a difference

[glacial otter]

its not a 2d game

[timid knot]

Ok, but that scene is, is it not?

[glacial otter]

nope

[timid knot]

Ok, so is sky playing an important role in that scene? Is it visible in any way?

[glacial otter]

whatever I do, the skybox is different

I can't make them similar

[timid knot]

Even with solid color?

[glacial otter]

the sky itself is not visible, but there are 3D characters, and on them, there can be materials which are reflective

I don't know to be honest

first I would be happy if I could set the skies on both Unity to be the same

[timid knot]

Well, then start reading the docs:
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/understand-sky.html

You can check the older version docs as well to make sure you understand how it works there

[glacial otter]

even if I set Sky type to None in both projects, they are different

for some reason

[timid knot]

How are they different?

[timid knot]

Are they sset to none here?

If yes, look at the frame debugger. Where is that rectangle coming from? it definitely isn't normal.

[glacial otter]

it seems to be that if I remove the camera in Unity 2022, then Scene view coloring will be the same as in Unity 6

so something is there in the camera

[timid knot]

Well, what do you see in the frame debugger, when there is just a camera in the scene?

[glacial otter]

I mean the game related camera

not the default instantiated camera

[glacial otter]

since I don't understand frame debugger, firstly I try to compare settings

okay, the 2 camera settings are exactly the same

[glacial otter]

I need to deal with something entirely else again, but later I will check it

[glacial otter]

@timid knot

its when only a camera is there

the game-related camera which was already in the scene before

[timid knot]

Well, one major difference is that exposure is calculated or written in the left case and not the right.

https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@14.0/manual/Override-Exposure.html#fixed

[glacial otter]

okay, now I inserted fixed exposure to unity 6 as well

with exact same value (0)

but the colors are still different in scene view

only the camera is active in both scenes

[timid knot]

This doesn't seem to be 0 though

[glacial otter]

in both unity

[timid knot]

check the values in frame debugger

[glacial otter]

they are the same

[timid knot]

Ok, great. Start stepping through the draw calls then and note things that are different.

Before that, can you compare these two exposure textures and make sure they have the same values?

[glacial otter]

this is an extra stage in Unity 6

[glacial otter]

already compared the red values, they were the same

in Gimp

[timid knot]

Dbuffer is a pass used for decals.
What draw calls does it contain?

[glacial otter]

4 pieces of Clear (color)

okay, I could remove that

by disabling the Decals

[timid knot]

Clearing the render targets it unrelated.
Start from the bottom and step through every draw call upwards.

[glacial otter]

the Decals option exists only in Unity 6 camera, not on the Unity 2022 camear

so above Deferred Lighting, its black

on Deferred Lighting, its already have the grey-ish color

[timid knot]

On what draw call in deferred lighting?

[glacial otter]

on all of them

[timid knot]

Then look at the differences in each of the draw call

[glacial otter]

different format

[timid knot]

That's clearing the render target.

Do you have hdr color enabled in the render pipeline asset on both versions?

[glacial otter]

@timid knot

_LightLayersTexture is not in Unity 6

[timid knot]

Also, check these setting: In Player Settings, the setting PreserveFramebufferAlpha

[glacial otter]

where is that?

[timid knot]

Render pipeline asset. Though maybe there isn't in hdrp..?

[drowsy dagger]

Have you checked your material? , maybe u material is the problem

[timid knot]

https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/HDR-Output.html

[glacial otter]

that would be weird, since there's no active material now

[timid knot]

And while you're there, make sure that the color space is the same in both versions.

[glacial otter]

this is disabled on both Unity

also there's VolumetricCloudsShadowTexture in Unity 6

and RenderingLayersTexture in Unity 6

but Volumetric Clouds is disabled...

@timid knot

[timid knot]

Is there anything in that texture? If not, it's probably unrelated.

[glacial otter]

there is

these definitely can darken the screen in Unity 6

[timid knot]

I don't think so. It seems to be basically a mask:
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.4/manual/Rendering-Layers.html
If it's black it doesn't have an effect whatsoever.

But it seems like you can disable them, so maybe try that to be sure.

[glacial otter]

then where might be the issue

I can only see that volumtric clouds shadow texture

which is suspicious

but volumetric clouds and their shadow is disabled...