Make Denoiser work with Exposure Control???

[aaronfross]

Hello,

The Denoiser is a great tool for bringing render times down to something reasonable. Unfortunately, Noice does not work with Exposure Control, since all AOVs are saved as raw. This is a problem for the many 3ds Max users who rely on Exposure Control for white balance and tonemapping.

In the past, I have experienced resistance from the Arnold team regarding white balance and tonemapping in the renderer. I was told that the proper way to do these things is in post-production. However, the reality on the ground for many 3ds Max users is that they rely on the native 3ds Max tools for exposure, tone mapping, and white balance, all of which were included in 3ds Max for a reason.

At the very least, I want to apply white balance to the Denoiser AOV, but apparently this is not possible in 3ds Max. I'm sure I could do it in Maya using a Blackbody node as a Camera Filter. However, there is no mechanism in MAXtoA for applying a Camera Filter. The only way to white balance a camera is through Exposure Control, which, again, is ignored by all AOVs, including the Denoiser.

The larger problem is that there is no option to include Exposure Control in any AOVs. But in the short term I would be happy if we could simply apply Exposure Control, or even just white balance, to the Denoiser AOV.

One possible solution might be to implement the Exposure Control code as part of an Arnold Camera modifier, similar to the Arnold Properties modifier for mesh objects. If we could even just have an Arnold Camera modifier that accepts a Filter, that would be a huge step in the right direction. Then users could construct their own shading networks to assume the functions of Exposure Control.

I understand that Arnold came from an environment of motion picture production, where all tonemapping etc. is automatically assumed to be done in post. But as Arnold is now the default renderer for 3ds Max, whose user base has varying workflows and expectations, it behooves the Arnold team to consider the needs of all users. For example, architectural visualizers need full support for Exposure Control, or at least a mechanism to achieve similar functionality in Arnold. If these users are not considered important enough to support, then they will never adopt Arnold. Leaving them out in the cold means they will continue to turn to other renderers, such as V-Ray.

Thank you,

Aaron

[nicola.stefano.jannuzzo]

Hi Aaron.
The Arnold cameras DO have an exposure control (not exposed by the plugin).
You can query the parameters of a node using kick. For example, for the perspective camera

kick -info persp_camera

As such, you can use a simple Set Parameter operator to override its value:

With this Selection string you are basically setting the exposure parameter to all the nodes of type persp_camera.

Does that help ?

[aaronfross]

Nicola,

Thank you for your response. Unfortunately, this does not help with the camera Filter Map limitation. Using kick, I see that there is a "filtermap" parameter for the persp_camera node. What expression would I enter into the Set Parameter operator in order to assign a particular node instance to the camera filter map? Let's say I have a Blackbody node named "white balance", with a whitespace in the name. How would I tell Arnold to assign that node to the filter map of all perspective cameras?

Thank you,

Aaron

[aaronfross]

Also, this does not address the problem that 3ds Max Physical Camera Exposure Control is not supported in AOVs. I'm not just talking about the exposure value. I'm talking about all of the features in the Environment and Effects dialog. There's a lot more in there than just the EV number. There's tonemapping built in. There's white balance built in. All of this is supported in the beauty pass rendering, but none of it is supported in AOVs. It would be very helpful if the native 3ds Max Physical Camera Exposure Control could be supported by AOVs, or at the very least, the denoiser_RGBA AOV.

Thanks again.

[RGhost77]

I'm also interested in this theme.

So what we have:
1. Max tone mapping with unknown algorithm which can not be reproduced outside of 3ds max.
2. Arnold not fully support Max's tone mapping.
3. Max dosn't have any functionality to use external tone mappers.

So it makes tone mapping inside Max uselless when we work with Arnold. So only way render in linear and do tone mapping outside of Max, but we must do it with blind eyes because we don't see result when setup light on scene in 3ds max.

Adsk definitely should do something with tone mapping inside of Max to make it works with Arnold!

[aaronfross]

"we must do it with blind eyes because we don't see result when setup light on scene in 3ds max"

This is the key. Design visualizers need a full featured WYSIWYG frame buffer. This is not currently possible in MAXtoA. It works up to a point, and then it doesn't work. The point at which it stops working is when the user want to use Noice.

I can't stress this enough... 3ds Max users, especially design visualizers, absolutely rely on tonemapping in the frame buffer. But it appears that tonemapping in the frame buffer is antithetical to the existing philosophy of the Arnold developers. Well, if Autodesk wants design visualizers to embrace Arnold, then the former Solid Angle team is going to need to re-evaluate their philosophy.

We've already seen some compromise in the rigid mindset around the religious purity of the unbiased algorithm. Adaptive sampling is a form of bias. Denoising also muddies the waters. No longer is Arnold a perfect, idealized, unbiased simulation of light propagation. If Autodesk wants to gain some market share back from V-ray, etc., then Solid Angle is going to need to embrace a more inclusive vision of what Arnold can be. And the key feature that absolutely must be supported is some form of tonemapping. A very large segment of the user base needs this, it's not optional for them.

So again, please either support Exposure Control in AOVs, or provide some GUI method of achieving that same result, e.g. through an Arnold Camera modifier.

Thanks.

[pproestos]

I guess the only way to get tone mapping + denoising within arnold is to use a very expensive

rtx card, rendering with gpu and forget about cpu...

[hitecom8172]

Mtoa is currently first priority for devs as it has the most users and it was meant for Maya. So good luck using Max. I'd use SketchUp or Maya.

[madsd]

That is simply not correct.
I had hole through on a specific technical thing out of public reach as the first guy among all hosts and I use max.