here I demostate how we manually turn an Octane exported ACES to a looking more close to the original viewport
https://render.otoy.com/forum/viewtopic.php?f=9&t=75843#p390014
karu wrote:The change to add the ability to export a scene-linear EXR file including the tone mapping settings (and a few related changes) just didn't make it into XB2, but it will be in XB3. The option is called "Force tone mapping"; in this case you would use it in conjunction with the default color space for EXR export (linear sRGB).
karu wrote:There appears to be a difference in saturation between the XB1 and XB2 screenshots. I guess this is a change in the scene? Nothing should have changed so let me know if it's the exact same scene.
karu wrote:The EXR ToneMap image is too bright due to Photoshop interpreting sRGB as linear sRGB (or equally, Octane passing sRGB off as linear sRGB on export), as we discussed before. XB3 fixes this by never saving a non-linear color space to an EXR file.
karu wrote:[*] The EXR Linear image is darker than the Octane Viewport due to using Photoshop's tone mapping instead of Octane's tone mapping. Neither one is objectively "right"; there are just many different methods of preparing a scene-linear image for display (this is something that OCIO can address, if used consistently across all applications).
karu wrote:[*] The difference between the PNG Tonemap image and the Octane Viewport image is interesting, and not something I can reproduce myself. I would guess that it's due to different display color management between Octane and Photoshop. Are you using the same display color profile in both applications?[/list]
funk wrote:Thanks team.
I submitted a bug in the previous thread:
viewtopic.php?p=389103#p389103
The scene renders now, but seems to be missing (or has very little) motion blur when compared to 2020.1.5
You can make this more obvious by changing animation settings > shutter time = 100%
jimho wrote:one minor comment on so called "sRGB Linear",my view is a linear color space is Gamma=1.0, and as we allknow sRGB color space is Gamma=2.2, it is a bit confuse what is a "sRGB linear" it should either be sRGB or Linear, it seems in XB2 there is actually no real linear, means gamma=1.0 export which is original pure EXR.
jimho wrote:karu wrote:[*] The EXR Linear image is darker than the Octane Viewport due to using Photoshop's tone mapping instead of Octane's tone mapping. Neither one is objectively "right"; there are just many different methods of preparing a scene-linear image for display (this is something that OCIO can address, if used consistently across all applications).
If a Linear image is produced correctly it should be greyish, it is like raw file with no color profile.
jimho wrote:I did some test on the ACES,yet I did not see the current OCIO or ACES have more advantage than adobe's resolution, per color management point of view,
https://render.otoy.com/forum/viewtopic.php?f=9&t=75843#p390014
My observation on OCIO, it is politically get more manufacturers involved, and it is more rely on re-mapping the images, on the other hand Adobe's icc and color profile solution is keeping the original image data unchanged,
and attached icc to define transform formular, which I think is a better free-lossless solution, though it seems much older.
as well, OCIO is not conflict with adobe's color management, OCIO is actually rely on icc for what it is good for.
Anyway, If you think OCIO works, could you provide some samples or tutorial on how to do this?
jimho wrote:karu wrote:[*] The difference between the PNG Tonemap image and the Octane Viewport image is interesting, and not something I can reproduce myself. I would guess that it's due to different display color management between Octane and Photoshop. Are you using the same display color profile in both applications?[/list]
tonemaped PNG is the closest to the viewport, the difference is quite subtle, I guess on sRGB system it is unnoticeable, no offend, you might find the differenc on a real wide gamut display...
jimho wrote:when opening in photoshop, all the image is using octane's by default "builtin RGB profile" to import(see below snapshot),
karu wrote:The color space that Octane calls "linear sRGB" has the same red, green and blue chromaticities as sRGB, and the same white point as sRGB, but uses a linear transfer function instead of the sRGB transfer function*. That is, linear sRGB is a linear version of sRGB. (Since the primary chromaticities and white point of sRGB are the same as those of Rec. 709, it would also be correct to refer to this color space as "linear Rec. 709", but we chose linear sRGB to clarify the relationship between it and sRGB). Some software just calls this color space "linear", which is very unhelpful because that name implies nothing about primary chromaticities or white point (e.g. ACES2065-1 is also linear).
* (The sRGB transfer function is closely approximated by gamma 2.2 but is actually a more complicated piecewise function.)
karu wrote:My point was that there is no definitively correct way to display a scene-linear image. There are artistic decisions to be made regarding how to bring the brightness of the scene into the range of the display device, how to account for differences in white balance between the scene and the viewing environment (based on the extent to which the viewer will be adapted to the white of the display vs. the white of the surround), other psychological differences due to looking at a rectangular screen instead of being inside the scene... This PDF is a huge read, mainly about gamma, but very informative: https://poynton.ca/~poynton/notes/PU-PR-IS/index.html
karu wrote:I think the issue here is that Photoshop (unlike most other applications) interprets untagged PNG files as being in whatever working space you have set, rather than sRGB. Since the vast majority of PNG files in the world are untagged, and the vast majority of those are in fact sRGB,
karu wrote: if you have a fancy working space set up, any random untagged PNG from the internet will just look wrong when opened in Photoshop.
jimho wrote:the above twocomparison, the png are both tagged the screen's color profile, which meet the viewport best,
there are slightly different when change the response curve from sRGB to gamma2.2, that is why I made each of them,and they are all accordingly, Left: PNG exported from the viewport at right(which respond curve has been changed),
the below comparison: PNG are as you instructed tagged sRGB.icc, the result looks differnt to the viewport where the image exported from
These result has been described a few times in the early different posts, here just provide evidence, as mentioned if you are using a pure sRGB system, you can see the difference from your web browser(because I did CM on it),
but you cannot reproduce this.
karu wrote:Are you sure you're using the same display color profile in both Octane (Preferences > Color management) and Photoshop (which seems to take its settings from Windows color management settings)? Except for possible rounding differences, you should see the exact same result as the Octane viewport by exporting a PNG from Octane and displaying in Photoshop with an sRGB profile assigned. The screenshots you posted seem to be consistent with display color management being disabled in Octane (i.e. the display color profile being set to sRGB).
jimho wrote:karu wrote:Are you sure you're using the same display color profile in both Octane (Preferences > Color management) and Photoshop (which seems to take its settings from Windows color management settings)? Except for possible rounding differences, you should see the exact same result as the Octane viewport by exporting a PNG from Octane and displaying in Photoshop with an sRGB profile assigned. The screenshots you posted seem to be consistent with display color management being disabled in Octane (i.e. the display color profile being set to sRGB).
I see,yes, you are right.
In 2020.2, when in Octane ColorManagement, if choose sRGB, it will be consistancy with previous versions(2019and prior), means the PNG result need tag screen color Profile as before
when chooce screen in the preference, the result need to tag sRGB.icc.
Interesting...
Return to Development Build Releases
Users browsing this forum: No registered users and 9 guests