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View Transform and Look settings are ignored in LookDev mode
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Description

System Information
Windows 10, Quadro 4000

Blender Version
Broken: c86b5fa820d181c2beabdf4147ac17cb6ff8149b
Worked: before mentioned commit

Short description of error
Since the aforementioned commit, any change of View Transform or Look is entirely ignored by Workbench and LookDev mode, which to me makes no sense at all. I've created this bug report to check if everyone is fine with this change. Also Exposure and Gamma settings are ignored by LookDev. Knowing the artists on my team, I'm sure they do tweak these settings while creating shaders, to see how materials react on light condition changes. Also, we're using an external OCIO configuration instead of the one shipped with Blender (we use the original Filmic GIT repo and made some own modifications there). With this commit, LookDev becomes rather limited to us.

I appreciate the separation of Eevee and LookDev a lot, since I can easily check what happens if I don't use scene lights, and try out other environments. But if I cannot use the same View Transform as with Eevee Render Mode, I have to do a lot of tweaks either again, or not use LookDev at all to be on the safe side.

Even in Workbench mode I'm not entirely sure if this change is a welcome one, but I guess we could live with it. Haven't checked if this change goes through down to OpenGL renderings too. If so, the colors of my masks (which I generate using Random Color mode with flat shading) become mangled - they really need to be exported as sRGB EOTF.

Exact steps for others to reproduce the error
Start Blender using Factory settings, Go to LookDev mode, and change View Transform, Look, Exposure or Gamma - nothing changes. Only Display Device is considered. Note that at the moment you have to rotate your 3D View to see CM changes updating.

Details

Type
Bug

Event Timeline

Wo!262 (wo262) rescinded a token.
Wo!262 (wo262) awarded a token.
Wo!262 (wo262) added a subscriber: Wo!262 (wo262).EditedNov 6 2018, 2:38 PM

Yeah, I'd like for the HDRs of Lookdev to use the scene's Color Management settings as well, minus the exposure settings, unless you turn scene lights on

As for the Workbench, Matcaps and Studio lights depend a lot on the intention of how they were created. Some matcaps benefit from Filmic, like EXR matcaps of materials with highlights, like porcelain, rubber, sculpt clay, etc. while others should be sRGB, like all the custom PNG matcaps I imported, and even some of the EXR ones, like normal map or horizontal lines. Studio lights are ok for the most part, except some of them have weird darkenings. I propose for Matcaps and Studio lights to switch View transform on an individual basis, controlled maybe by flags written on the filename of each, but not by the scene's color management. Just to throw it out there ^_^

I remember that for a while matcaps would use Filmic, the color pickers would also use filmic as well which was weird and wasn't even affected by the scene color settings. How to improve the color picker to have more transforms than gamma is another different history

Just to get this right: this only kicks in when you dont use Shading > Scene Lights in LookDev, right?
Once you do, you seem to be getting colormanaged output, right?
[So enabeling Scene Lights but hiding all lights plus not using Scene World would be what you are after?]

Whole point sounds reasonable to me, not sure if this was changed by design...
That being said, colormanagement is not my playground, adding the usual suspects here:

@Brecht Van Lommel (brecht), @Clément Foucault (fclem), @Troy Sobotka (sobotka) : opinions?

Philipp Oeser (lichtwerk) triaged this task as Normal priority.Nov 6 2018, 3:12 PM

@Philipp Oeser (lichtwerk) Well, when scene lights are enabled from the Shading Popover, Color Management is fully applied to the viewport in LookDev mode. Thanks for pointing this out. The problem is, in my scene I have a lot of area lights illuminating an interior like LED strips. The viewport becomes unusably slow if they are enabled, so that's not really a route for me to take. I fail to understand the benefit of not applying the selected View Transform if scene lights are turned off. Especially because there is zero indication in the UI that the transform is overridden, and neither is indicated by what it is being overridden. Maybe the decision was clever and I just don't see the reason yet, that's why I'm asking the question.

We already agreed to apply the View Transform and Look into LookDev mode, but still ignore the Exposure. That hasn't been implemented yet, and I'm not entirely sure it's the right solution yet.

The problem is that the view transform, look and exposure are all used to tweak what the final render looks like. This might be very dark or have some artistic look, which gets in the way when modeling, sculpting, or texture painting. Further if you don't use Filmic or a similar transform, your viewport will look washed out when using matcaps or lookdev mode, and it's not great to have that when loading existing .blend files created in earlier version. We want working display modes to be always clearly shaded regardless of the artistic choices for the final render.

@Rainer Trummer (aliasguru): regarding the (temporary) workaround of enabling Shading > Scene Lights: I meant you can hide all lights on top of that setting (easiest to put them all in a collection and hide it) to get you speed back... and have colormanaged HDRI influence...

We want working display modes to be always clearly shaded regardless of the artistic choices for the final render.

This isn't going to be possible. We also have to remember that the view transform is going to be handling the primaries, as such it is much more than just the transfer function.

Specifically, if the primaries are wide gamut such as REC.2020, the transfer function itself will change accordingly. And this doesn't take into account various things like the many sweeteners in something like ACES.

There won't be a one-size fits all, and even if there seemed to be, it would break fundamental colour management.

@Brecht Van Lommel (brecht) Thanks for your feedback, it's really cool that parts of CM are re-introduced back to LookDev mode. I do understand that the topic is complex, as the Blender Devs are putting a lot of effort into making Blender more accessible and easy to use. As far as I gather the discussion, this is the main reason for the change, so people would find a consistent experience. However, I find it counter-intuitive for LookDev mode.

Yes, you have a valid point that if LookDev and Rendered View share the same Color Management settings, one is going to tweak the other. But from my perspective, that's exactly what I want. If I were to use a certain exposure for rendering, why use a different one for dialing in the shader? Same with gamma. Same with View Transform and Look. I'd like to share some thoughts using images to make the point clearer:

This is an excerpt of a final shot of a rendering I worked on a while ago. A spin-off was presented at BCon17:

This is the same shot at exposure level -2:

And here at -5:

What I should have noticed when doing this is that even though the engine is getting close to black very soon, the orange tank still sticks out as if it was kind of self-illuminating. This is a hint that there is a problem with the Albedo Color. It was a false assumption of a certain RGB triplet I made. While it looked fine in the final shot, the Exposure check revealed that I can really only use that material under the lighting conditions I prepared for the final scene. But PBR materials *should* allow to be used under very different lighting conditions. The problem is not the material, it's my false assumption.

If I had checked that triplet in LookDev mode using exposure checks, I'd have detected this. So to be clear: We use the exposure slider NOT to tweak final render exposures, but to CHECK albedo color consistency! That's why I see it as something important for LookDev mode.

I can see how it's useful to have control over exposure in LookDev mode. However there are many users using scene exposure to tweak final render exposures, and I don't think we want to break that. There are a lot of .blend files out there that if you open them look very dark or bright in lookdev mode, because it's not using bright or dark scene lights.

Perhaps the solution would be to fold "LookDev" functionality into the "Render" display mode, always following scene color management there. And then "LookDev" mode could be renamed to something like "Material" or "Preview", ignoring most of the scene color management settings. It could still have a per-viewport exposure setting.

@Brecht Van Lommel (brecht) I see. Well, if the exposure story is seen as an issue, I guess we can live with having exposure and gamma settings ignored. I don't want to complicate things too much, I'm just sharing my thoughts from a user/studio perspective. View Transform and Look however are a must-have, but this I gather was agreed already. If exposure and gamma are ignored, there will be a need to deal with this in the UI. Having the parameters there doing nothing will confuse the hell out of people.

I'm not a fan of tucking LookDev somewhere as a sub-setting to be honest. When it was introduced I thought initially "what's the point?", as it was so close to Eevee. Now after using it for a few months I'm a huge fan of it, because I can quickly preview scenes with my favorite environments without constantly setting them up, and check the material easily without light influence too. Having it very accessible in the UI is very important in IMHO.

@Philipp Oeser (lichtwerk) As a side note, the light hiding fails as soon as lights are part of a collection instance coming from another Scene, which is the case for one of my files. I'd rather prefer not to need to work around in this specific case.

@Rainer Trummer (aliasguru) : Not sure why the light hiding is failing for you (working fine here for collection instances [be it linked from another blend or coming from another scene]), if that is an issue please report a bug for that as well.
I just noticed though that in the "instance" case, there appears to be an issue with shadows (reported separately -- see T57693).
That being said, I dont wont to hijack the original report -- and I am not a big fan of this workaround either...

@Philipp Oeser (lichtwerk) Maybe a misunderstanding, it *technically* works, but it's not very convenient from a user perspective, that's what I'm trying to say. So no bug to report there.

just checking if this is still an issue? (as of rB0e5f97a3a1b3 CM seems to be respected in LookDev? -- havent hunted down the relating commit though...)

note there is another (loosely related) discussion in T58405 [which now adds Solid mode inconsistencies to the mix...]

This is still to be fixed.

T58405: Inconsistent Color management behavior for textures between Solid and Eevee seems to be a mix of this bug and some refresh issue.