Metal Material

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kintuX
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Re: Metal Material

Post by kintuX »

CodeHD wrote: Tue Apr 19, 2022 6:54 pm
kintuX wrote: Wed Apr 13, 2022 12:04 am Hi, long time no see & yet with all "physical correctness" in mind I'm still bedazzled by this n,k approach. How can data obtained @ https://refractiveindex.info/ be used to get "Physically correct results"?

ie:Corona renderer makes it clear: How to use Complex IOR for Corona Physical Material?

but in BlendLuxCore this still feels much like a gimmick and purely artistic choice
/as previously explained, mimicking M~R behavior w/o any real n,k correlation :?
unfortunately, the link isn't working here, so I can't compare what they write.

Also, sicne it's been such a long time ;) maybe you can elaborate a bit on what feels non-realistic to you?


Indeed, Corona's C4D helpdesk site is consumed by Chaos. :roll:
Here's new link - How to use Complex IOR for Corona Physical Material?


And, as noted, usage and control via n+k values here is purely artistic.
CodeHD
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Re: Metal Material

Post by CodeHD »

kintuX wrote: Wed Apr 20, 2022 8:32 am Indeed, Corona's C4D helpdesk site is consumed by Chaos. :roll:
Here's new link - How to use Complex IOR for Corona Physical Material?


And, as noted, usage and control via n+k values here is purely artistic.
Ok looking at that, the main difference I see is that Corona allows you to manually input n,k-values for RGB.

In (Blend)LuxCore, you can only input a fixed n,k-pair, or load data from a file. Internally this data from a file is converted to RGB-n,k-values.

So under the hood both use RGB-n,k-values, but the method to enter them is different.
kintuX
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Re: Metal Material

Post by kintuX »

CodeHD wrote: Wed Apr 20, 2022 6:41 pm
Ok looking at that, the main difference I see is that Corona allows you to manually input n,k-values for RGB.

In (Blend)LuxCore, you can only input a fixed n,k-pair, or load data from a file. Internally this data from a file is converted to RGB-n,k-values.

So under the hood both use RGB-n,k-values, but the method to enter them is different.
This then makes it quite tedious be precise (physically correct) and fast at same time, forcing user to take shortcuts aka artistic approach, which in turn diminishes full potential and power of LuxCore, and consequently also influencing confidence in artist and its engine.

Through years I realized economics behind visual arts & predictive renderings... it mostly revolves around effortless work + good result = (quality*quantity)/time = reward || joy to use a tool...

So, is there any way to better this workflow/UX situation?
CodeHD
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Re: Metal Material

Post by CodeHD »

kintuX wrote: Wed Apr 20, 2022 8:15 pm This then makes it quite tedious be precise (physically correct) and fast at same time, forcing user to take shortcuts aka artistic approach, which in turn diminishes full potential and power of LuxCore, and consequently also influencing confidence in artist and its engine.

Through years I realized economics behind visual arts & predictive renderings... it mostly revolves around effortless work + good result = (quality*quantity)/time = reward || joy to use a tool...

So, is there any way to better this workflow/UX situation?
I went back to check, and actually it was already so that you had the option of RGB inpout for n and k in LuxCore as well.
However, it is configured with a value limit in the range of 0 to 1, while for metals values up to 10 are typical.

With two lines of code changed this can be improved:
fresnel.png
I will try to also make the default window size wider, by default you don't see the decimal digits, then I would commit the change. (Edit: commited)
kintuX
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Re: Metal Material

Post by kintuX »

Yes, this is it! And works as expected.
My guess is, it's how it was intended from start, since everything was already in place. :)
TYVM for great work & co-op. 8-)


BTW
Do you happen to know, if it's possible to also add "Thin Film" feature?


-------------------------------
thinking aloud
Then, a couple of other desired things left here are better "energy conservation" & micro-roughness...
which, I assume are on whole other level :cry:
Anyways, considering everything, this is already amazing project and I feel glad being part of it.
CodeHD
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Re: Metal Material

Post by CodeHD »

kintuX wrote: Sat Apr 23, 2022 3:20 pm Do you happen to know, if it's possible to also add "Thin Film" feature?
Code seems to need almost only trivial to copy-paste from glass material onto metal. I've done it but getting unrelated compilation error that need solving before I can test.
Question is rather if that same model for thin film on glass should be applied to metal. But I think it was a mostly artistic approach anyways... So lets see if it looks useful.
kintuX wrote: Sat Apr 23, 2022 3:20 pm thinking aloud
Then, a couple of other desired things left here are better "energy conservation" & micro-roughness...
which, I assume are on whole other level :cry:
Anyways, considering everything, this is already amazing project and I feel glad being part of it.
energy conservation and micro-roughness would be part of implementing a differnt scattering function model.
That will be more work. However first a decision would be needed which model exactly is to be implemented.
kintuX
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Re: Metal Material

Post by kintuX »

CodeHD wrote: Sun Apr 24, 2022 4:50 pm
kintuX wrote: Sat Apr 23, 2022 3:20 pm Do you happen to know, if it's possible to also add "Thin Film" feature?
Code seems to need almost only trivial to copy-paste from glass material onto metal. I've done it but getting unrelated compilation error that need solving before I can test.
Question is rather if that same model for thin film on glass should be applied to metal. But I think it was a mostly artistic approach anyways... So lets see if it looks useful.
Since you put it this way, how about, if "Thin Film" is added to Glossy Coating? In which case it could be used w/ any/every material for a base :idea:

kintuX wrote: Sat Apr 23, 2022 3:20 pm thinking aloud
Then, a couple of other desired things left here are better "energy conservation" & micro-roughness...
which, I assume are on whole other level :cry:
Anyways, considering everything, this is already amazing project and I feel glad being part of it.
energy conservation and micro-roughness would be part of implementing a differnt scattering function model.
That will be more work. However first a decision would be needed which model exactly is to be implemented.
Sure thing. And, in this regard, it would be nice to know what's Dade future plan for LuxCore... is he decided already or still contemplating :?: :|
CodeHD
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Re: Metal Material

Post by CodeHD »

kintuX wrote: Sun Apr 24, 2022 7:04 pm Since you put it this way, how about, if "Thin Film" is added to Glossy Coating? In which case it could be used w/ any/every material for a base :idea:
Possibly. Lets see first if my transfer to metal works and (!) if the results are useful. I have been wondering about the ramifications of using it on a material that is not specular, like glass where you normally have it. I believe it should work, but maybe for high roughness it may look very unnatural.
kintuX wrote: Sun Apr 24, 2022 7:04 pm Sure thing. And, in this regard, it would be nice to know what's Dade future plan for LuxCore... is he decided already or still contemplating :?: :|
Only he can say that. I have no further news about his, or anyones, long term ideas.
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