Would it be possible to add AgX to the Tonemapping options?

[kitaedesigns]

Now that Blender 4.0 has switched to AGX being the default Tonemapping mode, does it make sense to add to add here as well so that assets look as similar as possible?

See more about AgX here.
https://github.com/EaryChow/AgX

[vanruesc]

Yes, support for AgX would be good, but I think we should wait until it's implemented in three. Then it should be possible to tap into that logic instead of implementing it twice.

Related dicussion: mrdoob/three.js#26479 (comment)

[kitaedesigns]

Ok thanks!

[VanderSP]

I started using three AgX today! and I also plan to use this POSTFX MIXER!!!!!!!!

[vanruesc]

Added ToneMappingMode.AGX in [email protected].

[kitaedesigns]

Hey @vanruesc thank you for adding AgX! This was a great addition. I'm testing using a baked lighting model between Blender AgX and threejs's and pmndr's AgX using the same HDR to light the scene at an intensity of 1, and no lights in the scene but still noticing some differences in color, namely the threejs version seems to be more washed out. Is this just a difference of how AgX is implemented in WebGL vs OpenGL?

[VanderSP]

Hey, AGX is not just agx... theres punchy, golden, idk many presets of something... threejs implemented agx but still thinking about the presets... maybe this is the issue, i think it deals with some kind of contrast... still so new... i leave my blender in PUNCHY lol

[vanruesc]

@kitaedesigns Please try comparing results with vanilla three first. Three's physically-based lighting model is not exactly the same as the one Blender uses so some differences are to be expected.

@VanderSP I think it's safe to assume that @kitaedesigns used the default AgX preset in Blender. Results would obviously differ if that wasn't the case.

[kitaedesigns]

Hi @vanruesc, yes here is a comparison with threejs and blender's AgX. Blender on the Left. Threejs on the Right. Using the exact same asset and cubemap.

Blender AgX with Exposure at 0 vs Threejs AgX with Exposure at 1.

If I manually adjust each one's exposure I can get them quite close but I think the expectation would be that Exposure of 1 with AgX tonemapping in Threejs should be the same as Exposure 0 AgX tonemapping in Blender.

[vanruesc]

Thanks, I think three's output looks more pale in comparison, but it's hard to tell with this model and a blurred background. A comparison of your original scene from this comment would be useful.

My current guess is that the visual differences between Blender and three are not caused by postprocessing and are therefore out the scope for this project. In that case, it might be worth a shot to create a forum post over at three to discuss this as a potential issue.

[kitaedesigns]

Ok I will crosspost in the AgX thread here mrdoob/three.js#27362

Here are the assets.

GLB
https://1drv.ms/u/s!AksR0p9ftT9Yjilvft0H-B_IUNun?e=ttLJdA

HDR (this is the blender default)
https://1drv.ms/u/s!AksR0p9ftT9Yjiy5yFGQuDXIsuKo?e=wBMQgz

[VanderSP]

Ah now i see... when comparing to threejs, we are on NONE/BASE... how do you are keeping it more constrasty? epxosure value? or envmapIntensity?

I did a test right now... looks like toneMappingExposure between 0.25 ~ 0.5 make it contrastier!
Edit 2: it´s not more contrastier as it loses highlights... sorry being boring with this.. its too new :D
Edit 3: Im liking to put 0.5 ~ 0.75 on toneMappingExposure and 0.75 ~ 4 on envMapIntensity depending of material

[kitaedesigns]

So far I've just been adjusting the exposure to match them as best I can but there seem to be some fundamental color difference. Apparently this is due to how exposure is calculated in Blender vs Threejs being totally different. mrdoob/three.js#27362