spectral rendering

Use this forum for general user support and related questions.
Forum rules
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
User avatar
Theo_Gottwald
Posts: 104
Joined: Fri Apr 24, 2020 12:01 pm

Re: spectral rendering

Post by Theo_Gottwald » Tue Oct 20, 2020 9:53 pm

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.
Get Blender-Quickbuttons and configure over 100 Blender-Buttons individual to your needs.
Visit my YouTube-Channel: Theo's Fun Videos and watch several Blender related Videos.
Join @Dreamstime and sell your Renderings to the world.

User avatar
MetinSeven
Posts: 120
Joined: Sun Aug 18, 2019 10:19 am
Location: Netherlands
Contact:

Re: spectral rendering

Post by MetinSeven » 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.
visualizer • illustrator • animator • 3D designer — metinseven.nl

User avatar
Sharlybg
Donor
Posts: 2483
Joined: Mon Dec 04, 2017 10:11 pm
Location: Ivory Coast

Re: spectral rendering

Post by Sharlybg » Wed Oct 21, 2020 7:53 am

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)
https://appleseedhq.net/features.html
Support LuxCoreRender project with salts and bounties

Portfolio : https://www.behance.net/DRAVIA

CodeHD
Posts: 396
Joined: Tue Dec 11, 2018 12:38 pm
Location: Germany

Re: spectral rendering

Post by CodeHD » Wed Oct 21, 2020 8:30 am

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 :?:

User avatar
MetinSeven
Posts: 120
Joined: Sun Aug 18, 2019 10:19 am
Location: Netherlands
Contact:

Re: spectral rendering

Post by MetinSeven » 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.
visualizer • illustrator • animator • 3D designer — metinseven.nl

User avatar
Sharlybg
Donor
Posts: 2483
Joined: Mon Dec 04, 2017 10:11 pm
Location: Ivory Coast

Re: spectral rendering

Post by Sharlybg » Wed Oct 21, 2020 8:57 am

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:
Support LuxCoreRender project with salts and bounties

Portfolio : https://www.behance.net/DRAVIA

User avatar
MetinSeven
Posts: 120
Joined: Sun Aug 18, 2019 10:19 am
Location: Netherlands
Contact:

Re: spectral rendering

Post by MetinSeven » 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.
visualizer • illustrator • animator • 3D designer — metinseven.nl

User avatar
Sharlybg
Donor
Posts: 2483
Joined: Mon Dec 04, 2017 10:11 pm
Location: Ivory Coast

Re: spectral rendering

Post by Sharlybg » Wed Oct 21, 2020 9:26 am

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.
Support LuxCoreRender project with salts and bounties

Portfolio : https://www.behance.net/DRAVIA

User avatar
MetinSeven
Posts: 120
Joined: Sun Aug 18, 2019 10:19 am
Location: Netherlands
Contact:

Re: spectral rendering

Post by MetinSeven » Wed Oct 21, 2020 9:41 am

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.
visualizer • illustrator • animator • 3D designer — metinseven.nl

CodeHD
Posts: 396
Joined: Tue Dec 11, 2018 12:38 pm
Location: Germany

Re: spectral rendering

Post by CodeHD » Wed Oct 21, 2020 9:45 am

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)

Post Reply