Help Topic: OCIO and LUT

[stevejjd]

Hi
I need some help regarding OCIO and LUTs.

I dont know anything about color grading, I just want my renders to look photogenic instead of raw.

Is some one able to explain how to properly use OCIO in the V-Ray frame buffer?

I downloaded the OCIO Zip from http://opencolorio.org/

and loaded it into the frame buffer…from this point I am confused.

Is there some profile I can load that makes it look filmic? ~ and how would I do that?

Thanks

**** UPDATE *****

I have always wanted Vray to look filmic with its renders instead of raw.
I did some research and found that companies use NUKE to treat the renders and make it look filmic.
Is it better to do look dev raw and then apply treatments later in NUKE?

What is the best workflow for a character look-dev artist in regard to LUTs, OCIO and ICC?
Are there any profiles that make the raw frame buffer image look like natural film?

Please have a look at this “Filmic Blender” I found;
http://www.blenderguru.com/tutorials/secret-ingredient-photorealism/

Filmic Blender

So apparently they are adding an OCIO profile to the rendering and I would like to do a similar thing inside of 3ds max + V-Ray. Is some one able to tell me how to set that up?

[stevejjd]

Thanks for your reply. I had no idea how complicated this stuff is…its crazy.

Please may you take the time to look at this;

ACES Filmic Tone Mapping Curve

I think maybe what Im asking for is a new Colormapping mode. Vray is set to use Reinhard for linear workflow. Is it possible to make a “filmic” tone mapping one based on something like the ACES Filmic Tone Mapping one?

Can Chaos Group just copy a Nikon, Canon, Leica DSLR’s film response tone mapping curve? ~ I dont know how to do it but I just want a better look that Raw rendering. I dont have enough time or money to get nuke and learn it. Please just make a new button for me that makes it look like a photo or film.

I dont really understand LUTs, OCIO, ICC and on and on and on…Is it possible to have in Vray what blender has ~ a filmic tonemapping option?

Kind regards

Steve ~

[kosso_olli]

I really like some of the ideas of the filmic tonemapping. But keep in mind that all of this still has to work with complex compositing setups, deep data etc.

[stevejjd]

@fraggle

I actually brought this up on other forum, but did not mention it here, as Chaosgroup is usually quite slow to adapt modern standards. I guess we will eventually have something to accommodate for this modern workflow, but it will probably take around 3 years Significant portion of the userbase is quite conservative and orthodox, so revolutionary improvements are usually met with mixed feelings instead of warm reception.

Yeah I see what you mean. Its very strange that Chaos Group gets 10/10 for listening to feedback and yet is conservative and orthodox.

Should I make this a new thread in the product suggestion forum?

If V-Ray doesn’t have filmic tone mapping then how to you apply a filmic treatment to a raw image? ~ What is the work around to make it look like a photo without making it look like instagram?

[stevejjd]

Yeah totally ~ for sure. I think Chaos group has the right balance.

By the way I found this https://vimeo.com/ondemand/tonemap

apparently is a far better workflow to render raw images a wide dynamic range and then tonemap in post.

I guess I’m just confused as to how to light, render, lookdev my scene. I’m stuck between making it perfect in the frame buffer or making it perfect in post.

After some research, I think its a bad idea to have filmic tonemapping within the render engine because it compresses the dynamic range of the image.

The Filmic tone-mapping would have to be done via the frame buffer as a post effect.

Maybe a tone mapping configuration could be made in Nuke and the exported into VFB just like a LUT file. It would be a non destructive way of applying tone mapping so that you can turn it on or off as you lookdev.

[Rens]

So this filmic thing is just a LUT? That blender page makes you believe all current renderers are broken.

[stevejjd]

@Art48

So this filmic thing is just a LUT? That blender page makes you believe all current renderers are broken.

Im reseaching now…actually the solution could be extremely simple! ~

Filmic Tonemapping is definetly NOT LUT…its really amazing! ~ I actually think that the frame buffer can do this as it already has super basic tonemapping controls…They just need to update them!!!

CHAOS GROUP PLEASE ADD THESE CONTROLS … THEY ARE BETTER THAT EXPOSURE CONTROLS

Here are the filmic tonemapping controls in Fusion. It gives so many controls over the highlights and shadows.

So Chaos group dont need to build an internal filmic tone mapping type of Color Mapping…just update the controls on the frame buffer with this filmic tone mapping contollers

Highlight Compression Macros for Eyeon Fusion + Foundry Nuke

Can we please have the controls as seen in the attached image for Vray ? PLEASE! haha

*****UPDATE*******

Im going to make this into a feature request but we want the Nuke style Filmic Tone Mapper controls for the VRay frame buffer

Highlight Compression Macros for Eyeon Fusion + Foundry Nuke

This is the Nuke controls. I think the Nuke and Fusion controls are essentially the same.

[Rens]

Ah ok, so yes it’s a colour correction/LUT with controls, the difference is that the Reinhard and sRGB examples are baked into the render. So technically you could apply this on a linear exr render in post as well, yes?

[stevejjd]

@Art48

Ah ok, so yes it’s a colour correction/LUT with controls, the difference is that the Reinhard and sRGB examples are baked into the render. So technically you could apply this on a linear exr render in post as well, yes?

Yes the workflow is to
- Set V-Ray and 3ds max to use Linear Workflow. The color mapping should be Reinhard with a burn value set to 1.0 and mode to none (dont apply color mapping) and Gamma 2.2. Use the V-Ray Render Setup > Frame Buffer and chose V-Ray raw image file
- Render out 16bit or 32bit .exr images because of huge dynamic range
- In Nuke or Fusion apply the filmic tone mapping which controls the highlights and shadows.

My idea is that instead of the super basic exposure and hilight burn controls in the VFB why not have the filmic controls? Would be amazing!

[stevejjd]

Excellent, Thank you for your feedback. I’m still figuring this stuff out. I want to make a product suggestion in the wishlist forum to Vlado but still dont know exactly what I’m talking about. Ill have a look at the video. Thanks

@Recon442 Can you please help me write the product request?

[vlado]

@vlado

I want to make a product suggestion in the wishlist forum to Vlado but still dont know exactly what I’m talking about.

Let me know when you figure it out. I myself would much rather prefer if people simply did this in post, as it is so much more flexible. If we put something in the VFB, it is very likely to be outdated next year when something else comes into fashion.

Best regards,
Vlado

[Oleg_Budeanu]

I think there should be response from Chaosgroup about what is this, why is it good/bad and why it should/not be implemented.
Looks like this requires some knowledge about how tonemapping is done, why Blender (for example) has option to change from sRGB to filmic tonemapping (that new fancy thing) and why actually it looks better after applying it
Now, when VRay sampling is adaptvie and we do not have headaches with irradiance map, adjusting materials subdivisions and etc - new things are poping out here and there, and i think that is normal.
I am quite sure VFB should not be overwhelmed with features and become new photoshop - you have separate software for this.

[Ihno]

If you were a Photographer (or film guy) you’d do much post work as well. Most likely you’d even photograph a color chart to be able to linealize your photo before post to get what vray gives you out of the Box… a linear image.
The point here is: Color correction tools are designed to work on linear images. And using them on non-linear images will make them act different and can also produce strange results. So, I see no reason for the “its modern/ its better” point. Since its definitely better to do the whole post at once! And not one part in the 3d package and another part in the compositing software.
Having that said, I’d find it useful to preview the post in the vfb. And maybe get some kind of a reference for the post.
Currently I use the VFB curves for that purpose and it never bothered me, though.

I find the whole OICO/LUT chaos also quite complicated. Probably due to the way the internet provides information: wrong, incomplete, hard to find.
Does anyone know a good tutorial/book or course to bring light into this?

[Oleg_Budeanu]

@vlado

I did not deny that photographers do not do post work anywhere in my post(s). The specific way Filmic Blender actually goes about it is quite smart, it uses Filmic Log instead of sRGB and then applies filmic curve on top of that.

This is not about turning VFB into post processing package, this is just about viewing the data that you render in V-Ray in something that better translates V-Ray’s shading and lighting for your eyesight. That is why camera manufacturers add response curves to their camera, so that once you capture a photograph, digitally, you get something that makes more sense to your eyes. Something that looks more like what you saw with your own eyes before you decided to capture it on a camera. And then most photographers bring it into Photoshop to stylize it to your liking. But that is not in conflict with having something better than sRGB as a base to look at.

I don’t think this comes down to the “it’s modern = it’s better” assumption, but rather “it looks nicer = it’s better” one

Cannot agree more with this. And explained actually quite good !

[Rens]

What would be the downside to having a couple of OCIO presets compared to the controls? And technically you could encode all the colour transforms in OCIO so you wouldn’t need both LUT and OCIO, correct?
But yes it would help to get more options for getting nice looks/colour transforms/luts directly into VRay without making things complicated and cluttered, which is the tricky part.

[vlado]

@vlado

That is why camera manufacturers add response curves to their camera, so that once you capture a photograph, digitally, you get something that makes more sense to your eyes.

No, not really. The response curves happen because of the way the specific hardware (film or sensor) responds to light (that’s why they are called “response” curves). From then on, digital cameras apply a number of post filters, some of which are controllable (sepia, saturation, face detection and skin enhancement etc.) I still believe the correct place for those effects is not the VFB exactly.

Best regards,
Vlado

[vlado]

@vlado

And then most photographers bring it into Photoshop to stylize it to your liking.

Most professional photographers also use professional cameras. Those typically keep the amount of additional post-processing to a minimum and closely stick to the sRGB standard. Point-and-shoot cameras on the other hand, usually apply a liberal amount of processing internally to make images more appealing. I can assure you that this processing is way more complicated than some simple filmic tone mapping

Best regards,
Vlado

[vlado]

The VFB already has enough control for the final look in my view; the curves allow to do practically any tone mapping you want. They can also mimic the filmic tone mapping if needed.

Best regards,
Vlado

[1funk]

You can actually use filmic-blender in V-Ray. Open config.ocio in a text editor and you’ll see this:

[B]# VRay users should uncomment the Filmic views below as VRay doesn't permit Looks[/B]
#    - !<View> {name: Filmic Very High Contrast, colorspace: Filmic Log Encoding, look: +Very High Contrast}
#    - !<View> {name: Filmic High Contrast, colorspace: Filmic Log Encoding, look: +High Contrast}
#    - !<View> {name: Filmic Medium High Contrast, colorspace: Filmic Log Encoding, look: +Medium High Contrast}
#    - !<View> {name: Filmic Very Low Contrast, colorspace: Filmic Log Encoding, look: +Very Low Contrast}
#    - !<View> {name: Filmic Medium Low Contrast, colorspace: Filmic Log Encoding, look: +Medium Low Contrast}
#    - !<View> {name: Filmic Low Contrast, colorspace: Filmic Log Encoding, look: +Low Contrast}
#    - !<View> {name: Filmic Base Contrast, colorspace: Filmic Log Encoding, look: +Base Contrast}
#    - !<View> {name: Filmic False Colour, colorspace: Filmic Log Encoding, look: +False Colour}
#    - !<View> {name: Debug, colorspace: Debug}

So just remove the # from the start of those 9 lines

[1funk]

I also see some people confusing filmic tonemappers with this OCIO config. It’s not the same thing.

Filmic blender is basically a log LUT with some preset OCIO “looks” (LUTs of custom curves) that are applied before the log LUT.