Network Rendering: Tonemapping problem

[marcatore]

Hi,
I've a scene exported from Blender and saved in bcf file format.

Network rendering seems working good but the preview of the image show me an image with no tonemapper applied.

This is the tonemapped image (there are some differences due to some textures changes but it's not these the problem)

And this is the preview in the Network Rendering tool

I've also seen that the saved PNG is the same of that preview.
Is it probably something wrong with the exporter?

[Dade]

I have the feeling you are using some Blender image pipeline/tone mapper (indeed, it is not available outside Blender). B.Y.O.B. can probably confirm

If you save the out in .exr format you may be able to import the image in Blender

[marcatore]

I've Photographer addon but it's disabled for that scene (all the cameras don't use it).

I'll try to disable completely the addon

[B.Y.O.B.]

How does the render look if you open it in luxcoreui? (available in the standalone download of LuxCore)

[Dade]

How does the render look if you open it in luxcoreui? (available in the standalone download of LuxCore)

I pretty sure it will be overexposed too, I have already seen this happen with some of the scene posted by Marcatore. B.Y.O.B., but it isn't the result of some Blender post-processing ?

Marcatore, if you delete everything in the scene but a floor/wall and some lights and you post the scene, it may be easier to find what is going wrong.

[B.Y.O.B.]

I pretty sure it will be overexposed too, I have already seen this happen with some of the scene posted by Marcatore. B.Y.O.B., but it isn't the result of some Blender post-processing ?

Not sure, we need the scene.
BlendLuxCore usually defines multiple imagepipelines, maybe the network render just picks the wrong one to preview? But this is just a wild guess.

[marcatore]

Tested with a super simple scene

inside blender

With Network Rendering

Inside Luxcore UI

this is the Blend file with bcf file inside the zip.

Other "strange" thing is that it seems that is not exporting the file format. It saves always as PNG.

[Dade]

@B.Y.O.B.: it looks like BlendLuxCore is internally rendering without gamma correction:

Code: Select all

[LuxCore][182.139]   film.imagepipelines.0.0.type = "NOP"
[LuxCore][182.139]   film.imagepipelines.0.1.type = "TONEMAP_LUXLINEAR"
[LuxCore][182.140]   film.imagepipelines.0.1.fstop = 15
[LuxCore][182.140]   film.imagepipelines.0.1.exposure = 0.0010000000474974513
[LuxCore][182.140]   film.imagepipelines.0.1.sensitivity = 100

and than exporting with the usual 2.2 gamma correction:

Code: Select all

film.imagepipelines.0.0.type = "NOP"
film.imagepipelines.0.1.type = "TONEMAP_LUXLINEAR"
film.imagepipelines.0.1.fstop = "15"
film.imagepipelines.0.1.exposure = "0.0010000000474974513"
film.imagepipelines.0.1.sensitivity = "100"
film.imagepipelines.0.2.type = "GAMMA_CORRECTION"
film.imagepipelines.0.2.value = "2.2000000000000002"

The scene "Color Management" seems to have gamma set to 1.0 in Blender. This is somewhat a bug, if you leave the gamma correction task to Blender, gamma should be set to Blender value when exporting the scene. Marcatore's scene has a gamma of 1.0 if I understand how Blender settings work.

Blender seems also to have some additional color transformation by having set the Display Device set to "sRGB". As I wrote in my first post, any kind of color management done inside Blender can not be replicate when working outside.

[marcatore]

As I wrote in my first post, any kind of color management done inside Blender can not be replicate when working outside.

This is not a good news.
If it's not really possible to have what we have in Blender outside it, could be possible to make in a reverse way: bypass any Blender color correction and create a LuxCore color management inside Blender?
I can understand that there should be problems but, speaking in general, it's very a pity to have this mismatch cause it make useless Network rendering for Blender users ( I have 3 nodes I could use at work that could do the same job of my workstation and in this way I'll be able to half the production time).
Is this mismatching (not referring to the possible bug) could be a problem for future renderfarm when some Blender user will upload something to render?

I hope that something could be done to fix it.

[B.Y.O.B.]

To be frank, I have no idea what Blender does in regards to color correction, gamma etc.
The images Blender shows and saves clearly have some gamma correction applied, otherwise they would be flat and bright. This even happens when gamma is set to 1 in Blender's color management settings ...

Maybe a solution would be to save an .exr without gamma correction when doing network rendering with LuxCore, and then load this unprocessed "raw" .exr into Blender at the end, where Blender's color management does whatever it does.