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Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 2:31 pm
by Dade
daros wrote: Mon Nov 02, 2020 1:48 pm
But since we have only two variables, material and light, it is not even so important. Color bleeding would behave proportionally in the same way even if the white material is 5% warmer or colder, or if light is 5% warmer or colder.
No, it does all the difference if you are using a matte (0.5, 0.5, 0.5) or matte (1.0, 1.0, 1.0). Or if you use a matte or glossy material.
Copper is copper but on what basis have chosen the material type anf the materials parameters of white material ?
Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 2:34 pm
by daros
I used rectangular led lights with a CRI 95 and measured kelvin of 4250.
The problem is not the copper image by itself. It's the relation of the full white image with the copper image which points to a color bleeding problem.
Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 2:39 pm
by daros
Dade wrote: Mon Nov 02, 2020 2:31 pm
daros wrote: Mon Nov 02, 2020 1:48 pm
But since we have only two variables, material and light, it is not even so important. Color bleeding would behave proportionally in the same way even if the white material is 5% warmer or colder, or if light is 5% warmer or colder.
No, it does all the difference if you are using a matte (0.5, 0.5, 0.5) or matte (1.0, 1.0, 1.0). Or if you use a matte or glossy material.
Copper is copper but on what basis have chosen the material type anf the materials parameters of white material ?
We used a common material which measures close to full white, natual lime. Then you told us white in lux coresponds to 0.7. So we did.
Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 2:50 pm
by daros
But wait, in a few days we should have much more tests and the problem will be easier to localize.
Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 6:04 pm
by CodeHD
daros wrote: Mon Nov 02, 2020 2:39 pm
Then you told us white in lux coresponds to 0.7. So we did.
I know this common reference, and wanted to nag about it before but kept forgetting... A regular good white paint can be over 90%. Reference for example:
https://digitalcommons.usu.edu/cgi/view ... nstruments
You mention "Natural Lime" explicitly, I didn't really find a clear general information on that, so you should check for your specific case.
When moving to a higher reflectance, make sure you increase the total path depth accordingly. Inside a closed white box, there will be many diffuse interreflections. What path depth did you choose, btw?
Re: Luxcore vs real Photo
Posted: Mon Nov 02, 2020 11:05 pm
by Sharlybg
CodeHD wrote: Mon Nov 02, 2020 6:04 pm
daros wrote: Mon Nov 02, 2020 2:39 pm
Then you told us white in lux coresponds to 0.7. So we did.
I know this common reference, and wanted to nag about it before but kept forgetting... A regular good white paint can be over 90%. Reference for example:
https://digitalcommons.usu.edu/cgi/view ... nstruments
You mention "Natural Lime" explicitly, I didn't really find a clear general information on that, so you should check for your specific case.
When moving to a higher reflectance, make sure you increase the total path depth accordingly. Inside a closed white box, there will be many diffuse interreflections. What path depth did you choose, btw?
This was my point since the begining. I am sure lot of super white materials goes above 0.7 or 0.85 of albedo reflectance.
Pure white lime look like magnesium oxide wich is above 0.85 to.
For the path deph we are on bidir 64 + 64 and already made test with 128 + 128 .
But Dade can maybe clarify if it is correct from the engine POV.
Re: Luxcore vs real Photo
Posted: Tue Nov 03, 2020 5:24 pm
by Sharlybg
Can Luxcore standalone use .cube LUTs file for tonemapping ?
Re: Luxcore vs real Photo
Posted: Tue Nov 03, 2020 5:57 pm
by B.Y.O.B.
Re: Luxcore vs real Photo
Posted: Tue Nov 03, 2020 6:09 pm
by Sharlybg
I can see the option but nothing to load the Luts in the viewport. is there a special process to follow ?
BTW this return error with Luxcore standalone and wann't render.
Re: Luxcore vs real Photo
Posted: Tue Nov 03, 2020 6:25 pm
by Sharlybg
I think i have understand how it should work. just that i can't apply it with my file not working with standalone luxcore.
