spectral rendering

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Theo_Gottwald
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Re: spectral rendering

Post by Theo_Gottwald »

Can you explain the picture?
From my point of view often when i use dispersion, many of the colours are missing and i get just R,G and B.
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MetinSeven
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Re: spectral rendering

Post by MetinSeven »

FarbigeWelt wrote: Tue Oct 20, 2020 7:17 pm Three Sided Prism.png
:ugeek:
Intriguing. Does this mean that LuxcoreRender yields physically correct dispersion results despite not being a spectral renderer? I'm not very familiar with this field yet.
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Sharlybg
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Re: spectral rendering

Post by Sharlybg »

MetinSeven wrote: Wed Oct 21, 2020 7:17 am
FarbigeWelt wrote: Tue Oct 20, 2020 7:17 pm Three Sided Prism.png
:ugeek:
Intriguing. Does this mean that LuxcoreRender yields physically correct dispersion results despite not being a spectral renderer? I'm not very familiar with this field yet.
I think luxcore only have spectral dispersion.
BTW appleseed seem to have full spectral rendering but i can see the impact on the appleseed gallery. :roll:
Spectral rendering (31 bands in 400-700 nm)
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CodeHD
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Re: spectral rendering

Post by CodeHD »

Sharlybg wrote: Wed Oct 21, 2020 7:53 am
I think luxcore only have spectral dispersion.
Another way to say this is that LuxCore is not a spectral renderer, but it has two spectral materials, namely Glass and the Thin Film Coating. (Granted, the latter is not a material on its own, but still...)

On each glass interaction, the refraction is calculated with dispersion, then a wavelength-to-RGB conversion is done, and what follows is done again in RGB space. See the example of a possible implication I posted here.

In the source code, I also see some spectral stuff in textures, but I think it is just to precompute RGB data based on physical inputs :?:
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MetinSeven
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Re: spectral rendering

Post by MetinSeven »

Sharlybg wrote: Wed Oct 21, 2020 7:53 am BTW appleseed seem to have full spectral rendering but i can see the impact on the appleseed gallery. :roll:
Looking at the Blenderseed update frequency, I've got the impression that Appleseed is not very alive anymore:
https://github.com/appleseedhq/blenderseed

I also believe that Appleseed is still CPU-only and that there's no macOS support.
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Sharlybg
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Re: spectral rendering

Post by Sharlybg »

MetinSeven wrote: Wed Oct 21, 2020 8:46 am
Sharlybg wrote: Wed Oct 21, 2020 7:53 am BTW appleseed seem to have full spectral rendering but i can see the impact on the appleseed gallery. :roll:
Looking at the Blenderseed update frequency, I've got the impression that Appleseed is not very alive anymore:
https://github.com/appleseedhq/blenderseed

I also believe that Appleseed is still CPU-only and that there's no macOS support.
Yes this is the precarity of opensource render engine. Even if there is amazing potential weakness catch up and kill everything.
This the reason i always say everyone involve in the project should think about way to support :

__ Report Bug
__ Share your Work
__ Donate
__ participate to community life (express your POV)
__ Code even small thing is welcome (addon / core engine)
__ Comment on other Lux work as much as you can on every platform

Don't want to spread fear among but we aren't far from that appleseed current state :mrgreen:
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MetinSeven
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Re: spectral rendering

Post by MetinSeven »

Sharlybg wrote: Wed Oct 21, 2020 8:57 am Don't want to spread fear among but we aren't far from that appleseed current state :mrgreen:
I think the Luxcore devs are doing a fine job with frequent build updates, improving GPU support and a macOS version.
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Sharlybg
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Re: spectral rendering

Post by Sharlybg »

MetinSeven wrote: Wed Oct 21, 2020 9:04 am
Sharlybg wrote: Wed Oct 21, 2020 8:57 am Don't want to spread fear among but we aren't far from that appleseed current state :mrgreen:
I think the Luxcore devs are doing a fine job with frequent build updates, improving GPU support and a macOS version.
Yes but all the Core engine stuff is on a single Man since Years now and the addon situation is pretty simillar.
After 3 years of rebirth i don't see any other Developper joinning core engine development.
Userbase is minimal. And even if there 1500 people subscribing to the forum i can count user participating
in the project life.

__Dez
__ MetinSeven
__ Theogottwald
__ Cgvirus
__CodeHD
__Farbigewelt
__b2przemo
__joyasrohrbach
__PDRA

Maybe i forget couple of names but it really doesn't change the picture that much.
It is fixable but not without coordination and communication and clear path definition.
Many are doing a great job exposing and supporting this amazing project but there is lack
of coordination concertation.
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MetinSeven
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Re: spectral rendering

Post by MetinSeven »

It'd be great if LuxcoreRender gets more recognized among 3D users. It is a truly great renderer, ahead of Cycles in multiple areas.

Once Luxcore gets more user attention, more donations and interested developers will follow.
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CodeHD
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Re: spectral rendering

Post by CodeHD »

Sharlybg wrote: Wed Oct 21, 2020 9:26 am Maybe i forget couple of names but it really doesn't change the picture that much.
There is also the Discord, with about a similar number of people who are very active. (Driven also by a very lively off-topic chat going on there)
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