How in the world does tonemap control work?

[Jpjapers]

Hi,

Ive just plugged in an image into the tonemap node and applied the tonemap to the environment slot in my image.
Regardless of the checkboxes in the map its still affected by both the EV control in tonemapping and the environment slot in lightmix.
I cant figure out how to keep the environment looking the same whilst adjusting these values.
Or am i misunderstanding how this works?
Any ideas?

Thanks

[TomG]

You did note the info in the control that says that you need to re-render? If you start IR, or finish a render, then adjust tone mapping, the background will still be affected (until you re-render). Let us know if that's not what you are experiencing, though :)

[Jpjapers]

You did note the info in the control that says that you need to re-render? If you start IR, or finish a render, then adjust tone mapping, the background will still be affected (until you re-render). Let us know if that's not what you are experiencing, though :)

Yeah i restarted IR a few times just to make sure but i experienced the same behaviour.
Is it tied down to the .HDR Format?

[TomG]

Should work with any image format - however, are you referring to the Beauty pass, or the LighMix pass? The LightMix will always be affected by changes to the LightSelect for the environment. I think that would be by design though, as the ToneMapControl isn't designed to exclude something from the LightMix (as you can individually control the LightSelect for it anyway). It does correctly stop EV from changing the background in the LightMix pass, but doesn't stop the changes to the LightSelect layer (at least in my test).

If you are experiencing something different, sharing the scene and description of expected / desired results would be good!

[dj_buckley]

I think i get what you’re saying.  Everytime you adjust the tonemapping controls in IR, it affects the background even though you have affected by tonemapping unticked. Right.  This is normal behaviour although personally I feel it defeats the object :)

If you have IR open and adjust the tonemapping settings, the background that you want to keep ‘as is’ will change along with the rest of the render.  However if you restart IR, you’re render will maintain those tonemapping changes but your background will ‘reset’ to how it was before you adjusted the tonemapping.

It’s not great but it is what it is.  It makes it almost impossible to match scene lighting to a photographic backplate dynamically.  50% of my work is taking site photos and then matching the 3d scene to it in terms of lighting/contrast/white balance/hc etc so what we really need is an option to display an image in the background that literally stays as is regardless of what you adjust

[Jpjapers]

I think i get what you’re saying.  Everytime you adjust the tonemapping controls in IR, it affects the background even though you have affected by tonemapping unticked. Right.  This is normal behaviour although personally I feel it defeats the object :)

If you have IR open and adjust the tonemapping settings, the background that you want to keep ‘as is’ will change along with the rest of the render.  However if you restart IR, you’re render will maintain those tonemapping changes but your background will ‘reset’ to how it was before you adjusted the tonemapping.

It’s not great but it is what it is.  It makes it almost impossible to match scene lighting to a photographic backplate dynamically.  50% of my work is taking site photos and then matching the 3d scene to it in terms of lighting/contrast/white balance/hc etc so what we really need is an option to display an image in the background that literally stays as is regardless of what you adjust

Im compositing some new fixtures into a site but ive only been provided with a 360 jpeg. So by cranking up the environment intensity i can get convincing enough lighting in situ but at the moment the background gets basically to all white before the objects match the lighting in the original image.

Basically in my mind tonemapping should exclude the image itself from any changes whilst allowing you to adjust the light output from the image to suit your compositing needs.

[TomG]

That's where a Direct Visibility background override would come in (but, that doesn't seem to have any effect when using LightMix, afaik). Perhaps saving it out with alpha and replacing the background in post might work in the meantime?

[Jpjapers]

That's where a Direct Visibility background override would come in (but, that doesn't seem to have any effect when using LightMix, afaik). Perhaps saving it out with alpha and replacing the background in post might work in the meantime?

Yeah that will work. Its my fault
, i misunderstood the purpose of the tonemap control node.
Thanks for the help gents

[maru]

hope this guide helps ;) https://coronarenderer.freshdesk.com/support/solutions/articles/5000522247