OctaneRender™ 2020.2 (XB1) is out! + 2021 roadmap updates! Tweet

[Goldorak]

EXR files are not supposed to be tone mapped, as EXR is explicitly a scene-linear format. See https://www.openexr.com/:

The purpose of format is to accurately and efficiently represent high-dynamic-range scene-linear image data and associated metadata, with strong support for multi-part, multi-channel use cases.

Octane provides the option to export an EXR file using the sRGB color space for backwards compatibility; this may be part of users' existing workflows and we didn't want to break them. However, in the 2020.2 release this option has been moved to the bottom of the list and tagged as not being scene-linear. Ideally, it shouldn't be used.

Photoshop is presumably seeing that you're loading an EXR file, and assuming that it's in a scene-linear color space, and so applying another gamma transform in order to display the image. This is a reasonable assumption for any EXR viewer to make. If you want to export an EXR from Octane using tone mapping, and then display that EXR in another application the same as how it appeared in Octane, you will need to find an application that doesn't assume EXR files are scene-linear (or is happy to send a scene-linear image directly to the display), or manually apply an additional ~0.4545 gamma to the image to cancel out the conversion from scene-linear that the viewer is doing.

Thanks for your explainations,

but it seems not improve anything in terms of user experience, and it sounds pretty strange to many of us.

1, exr tonemapped, the term is from octaine's UI which is there for many years till today, but you say here, it is a wrong term which is not supported, it is otoy who have the responsiblity to use a correct term, we just follow that, anyway we just refer to the exr's exporting option no matter what name it is called;

exr.JPG

2, if there is anything not recomended,probably you may name it unrecomended, put to the bottom should not have this funtion
3, if most viewer will translate the "tonemapped" EXR incorrectly can you make it "correct" ;means make the "0.4545"builtin for your "tonemap" option?
Can we suggest if you provide anything, provide it correctly or just do not provide it, neither donot provide it in a halfway?
It is nothing to do with how photoshop etc softewares translate exr, you, the software maker need to take this issue count in, when you coding this tonemapping, it just mean the current tonemapping for exr is not in a rightway. Can you fix it?

In short, it is still good to provide an exr option that keeps same looking with the viewport, just to adjust the way how you do the tonemapping i.e. builtin the gamma upon the linear exr, for better user experience.

I agree. will review with the team ahead of XB2.

[Goldorak]

Chromatic Aberration guys, don't forget please. They have long been implemented in all other renders.

As I mentioned in FB we have the fast CA for Brigade which we can bring to Octane and then the full spectral one which right now is kind of slow and may need more work. I doubt any other renderer is doing spectral CA the way we are, so it’s not apples to apples in any case.

[divasoft]

Chromatic Aberration guys, don't forget please. They have long been implemented in all other renders.

As I mentioned in FB we have the fast CA for Brigade which we can bring to Octane and then the full spectral one which right now is kind of slow and may need more work. I doubt any other renderer is doing spectral CA the way we are, so it’s not apples to apples in any case.

It's very interesting, thanks.

[funk]

I would also like to have chromatic abberation.

I use/test a few other renderers (vray, octane, modo, prorender, cycles) and none of those have chromatic abberation.

I'm curious which other renderers have it? You make it sound like everyone else has implemented it already.

EDIT: It looks like blender can do it as a post effect, using the compositor with the lense distortion node.

[coilbook]

Nice thanks.
Any planes for 7-frame temporal denoiser like disney has for animations so our noise wont jitter from frame to frame?

[karl]

EXR files are not supposed to be tone mapped, as EXR is explicitly a scene-linear format. See https://www.openexr.com/:

The purpose of format is to accurately and efficiently represent high-dynamic-range scene-linear image data and associated metadata, with strong support for multi-part, multi-channel use cases.

Octane provides the option to export an EXR file using the sRGB color space for backwards compatibility; this may be part of users' existing workflows and we didn't want to break them. However, in the 2020.2 release this option has been moved to the bottom of the list and tagged as not being scene-linear. Ideally, it shouldn't be used.

Photoshop is presumably seeing that you're loading an EXR file, and assuming that it's in a scene-linear color space, and so applying another gamma transform in order to display the image. This is a reasonable assumption for any EXR viewer to make. If you want to export an EXR from Octane using tone mapping, and then display that EXR in another application the same as how it appeared in Octane, you will need to find an application that doesn't assume EXR files are scene-linear (or is happy to send a scene-linear image directly to the display), or manually apply an additional ~0.4545 gamma to the image to cancel out the conversion from scene-linear that the viewer is doing.

Thanks for your explainations,

but it seems not improve anything in terms of user experience, and it sounds pretty strange to many of us.

1, exr tonemaped, the term is from octaine's UI, but you say here, it is a wrong term which is not supported, it is otoy who have the responsiblity to use a correct term, we just follow that, anyway we just refer to the exr's exporting option no matter what name it is called;

exr.JPG

2, if there is anything not recomended,probably you may name it unrecomended, put to the bottom should not have this funtion
3, if most viewer will translate the "tonemapped" EXR incorrectly can you make it "correct" ;means make the "0.4545"builtin for your "tonemap" option?
Can we suggest if you provide anything, provide it correctly or just do not provide it, neither donot provide it in a halfway?

In one word, it is still good to provide an exr option that keeps same looking with the viewport, just to builtin the gamma upon the linear exr, for better user experience.

That screenshot appears to be from an older version of Octane - that looks like the export render passes dialog which has changed in 2020.2. 2020.2 no longer simply uses the term "tonemapped" for this and instead clarifies that it's the choice of the sRGB color space that results in Octane performing tone mapping.

It is assumed that if a user chooses to export an EXR file in the sRGB color space with tone mapping applied, they have some reason for doing so (e.g. maybe the resulting image is being used in some software configured to interpret EXR files as sRGB). I would like to remove that option but it would be considered a regression by anyone who (going against the general conventions of the EXR format) uses it. It has at least been moved to the bottom of the list and clarified as including tone mapping and not being scene-linear.

You can simply use the non-tone-mapped option (e.g. the default "Linear sRGB (scene-linear)" color space) to produce an EXR file with scene-linear image data. This should display as expected in any application that displays EXR files. Note that this will not include any of the tone mapping transformations from the camera imager node (e.g. response curve/gamma/custom LUT) because those are part of a display transformation, which is not relevant to the scene-linear image data stored in EXR files.

If you want to export an image and have it display in another application exactly as it displays in the Octane viewport, you should export as PNG, which is a display-referred format with any display transformation baked in. Alternatively, if you are using OCIO (and the other application supports OCIO), you can export as EXR and make sure to view the image in the other application using the same OCIO view and look as you were using in Octane.

[jimho]

That screenshot appears to be from an older version of Octane - that looks like the export render passes dialog which has changed in 2020.2. 2020.2 no longer simply uses the term "tonemapped" for this and instead clarifies that it's the choice of the sRGB color space that results in Octane performing tone mapping.

It is assumed that if a user chooses to export an EXR file in the sRGB color space with tone mapping applied, they have some reason for doing so (e.g. maybe the resulting image is being used in some software configured to interpret EXR files as sRGB). I would like to remove that option but it would be considered a regression by anyone who (going against the general conventions of the EXR format) uses it. It has at least been moved to the bottom of the list and clarified as including tone mapping and not being scene-linear.

You can simply use the non-tone-mapped option (e.g. the default "Linear sRGB (scene-linear)" color space) to produce an EXR file with scene-linear image data. This should display as expected in any application that displays EXR files. Note that this will not include any of the tone mapping transformations from the camera imager node (e.g. response curve/gamma/custom LUT) because those are part of a display transformation, which is not relevant to the scene-linear image data stored in EXR files.

If you want to export an image and have it display in another application exactly as it displays in the Octane viewport, you should export as PNG, which is a display-referred format with any display transformation baked in. Alternatively, if you are using OCIO (and the other application supports OCIO), you can export as EXR and make sure to view the image in the other application using the same OCIO view and look as you were using in Octane.

if for any reason you do not want to change the current sRGB tonemapped EXR,
Can you add a new EXR option which can have the RIGHT appearance in photoshop, just simply integrated the 0.4545 into the current version of sRGB tonemapped EXR?
OCIO is far more complicated than what I am suggesting here, for such a simple purpose, it is not worthy

[funk]

An option to linearise that tonemapped EXR might be good. It will avoid having to manually gamma correct it in PS.

I actually wouldnt mind if the tonemapped beauty + tonemapped denoised could just become extra passes.

Then I would have the linear + tonemapped versions in my layered EXR.

[jimho]

An option to linearise that tonemapped EXR might be good. It will avoid having to manually gamma correct it in PS.

I actually wouldnt mind if the tonemapped beauty + tonemapped denoised could just become extra passes.

Then I would have the linear + tonemapped versions in my layered EXR.

agree

[whersmy]

You can simply use the non-tone-mapped option (e.g. the default "Linear sRGB (scene-linear)" color space) to produce an EXR file with scene-linear image data. This should display as expected in any application that displays EXR files. Note that this will not include any of the tone mapping transformations from the camera imager node (e.g. response curve/gamma/custom LUT) because those are part of a display transformation, which is not relevant to the scene-linear image data stored in EXR files.

Hi karu,

Is there a 100% correct way to set the Order? (see attached ss)

I`ve got a response curve applied as well as a LUT and would like to save out an .EXR. I often find myself adjusting the EXR in PS a bit as it comes out a bit too bright when exported as Tonemapped .EXR.