Node setup for volume absortion

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lighting_freak
Posts: 234
Joined: Thu Jan 18, 2018 6:02 pm

Node setup for volume absortion

Post by lighting_freak »

Hi all,

I want to create a glass material with polished surfaces and a volume that absorbs blue light.
I know the absorption coefficient by wavelength. Is it possible to transfer these in luxcorerender?

If not, is there a simplification possible that allows me to absorp 0.2% of blue light per mm?

While testing it'd see that the material preview doesn't change in terms of colour while scaling the sphere size. This might be a bug.

Thanks for taking care
BR
OS - Windows 7 X64
CPU - Intel CORE i7
GPU1 - Variants of notebook card from nVidia
GPU2 - Variants of notebook onboard card from Intel
Lux - Latest possible relaease
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B.Y.O.B.
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Re: Node setup for volume absortion

Post by B.Y.O.B. »

In BlendLuxCore, you don't specify the absorbed color, but the resulting color after absorption at a given depth. This is much more artist-friendly, however in your case you might want to remove this implicit "colordepth" texture in this part of the code: https://github.com/LuxCoreRender/BlendL ... __.py#L228
(Just delete or comment out the whole if/else block)

About the rest, maybe Dade can comment, because I can't help with that.
lighting_freak
Posts: 234
Joined: Thu Jan 18, 2018 6:02 pm

Re: Node setup for volume absortion

Post by lighting_freak »

Hi,

OK for me... my new request is to transmit 99.8% yellowish light per mm! :D
I'm really not sure how top define such a blendluxcore-node. Thanks for your help.

BR
OS - Windows 7 X64
CPU - Intel CORE i7
GPU1 - Variants of notebook card from nVidia
GPU2 - Variants of notebook onboard card from Intel
Lux - Latest possible relaease
User avatar
B.Y.O.B.
Developer
Developer
Posts: 4146
Joined: Mon Dec 04, 2017 10:08 pm
Location: Germany
Contact:

Re: Node setup for volume absortion

Post by B.Y.O.B. »

Sorry for the late reply.
Something like the attached scene, I guess.
But you will have to investigate how to input your wavelength values correctly, how to handle sRGB conversion etc., I can't help you there.
Maybe use LuxCore's conversion function: https://github.com/LuxCoreRender/LuxCor ... ss.cpp#L46
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