The pink elefant

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B.Y.O.B.
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Re: The pink elefant

Post by B.Y.O.B. » Tue Jan 02, 2018 10:52 pm

Dade wrote:
Tue Jan 02, 2018 5:08 pm
Uh, I never tried with TILEPATH, strange, going to check ... it doesn't seems to happen here (it may be a different problem, not related to dispersion), can you post how reproduce the problem.
Yes, seems like it is not related, I created an issue here: https://github.com/LuxCoreRender/LuxCore/issues/31
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Dade
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Re: The pink elefant

Post by Dade » Thu Jan 04, 2018 11:44 am

I have implemented the solution discussed here (https://github.com/LuxCoreRender/BlendL ... 1bccefb530) for parameters.

Glass ".dispersion" property has been removed, Glass ".cauchyc" float texture parameter has been added with the support for IORs computed by Cauchy's equation (Cauchy's B is internally automatically computed from IOR). If not defined, dispersion is disabled. IORs texture are again used as float, not RGB:

Code: Select all

scene.materials.Cubo_Prism_01_MAT.type = glass
scene.materials.Cubo_Prism_01_MAT.kr = 1. 1. 1.
scene.materials.Cubo_Prism_01_MAT.kt = 0.8 0.8 0.8
scene.materials.Cubo_Prism_01_MAT.ioroutside = 1.0
scene.materials.Cubo_Prism_01_MAT.iorinside = 1.4
scene.materials.Cubo_Prism_01_MAT.cauchyc = 0.025
Simon, as expected, you can ".cauchyc" parameter as "strength" value. You may have only to use a large value for the max. (to exaggerate the dispersion for artistic purpose). For people using measured material data.

It may be nice to have an additional "Advanced" flag to allow direct user inputs of Cauchy's equation B and C (instead of IOR and "Dispersion strength").

P.S. IOR = B + C / (589 / 1000)^2
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Dade
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Re: The pink elefant

Post by Dade » Thu Jan 04, 2018 11:54 am

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Re: The pink elefant

Post by B.Y.O.B. » Thu Jan 04, 2018 1:41 pm

I implemented support for the new cauchyc parameter in BlendLuxCore.

Do you plan to also add this feature to roughglass?
(just asking because if not I'll deactivate the dispersion socket if the glass node is set to "rough")
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Dade
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Re: The pink elefant

Post by Dade » Thu Jan 04, 2018 2:42 pm

B.Y.O.B. wrote:
Thu Jan 04, 2018 1:41 pm
Do you plan to also add this feature to roughglass?
(just asking because if not I'll deactivate the dispersion socket if the glass node is set to "rough")
It may sounds strange but it would be more complex than the implementation of glass (because glass is a pure specular material, no direct light sampling while roughglass is not and has to support direct light sampling)

In 10 years of LuxRender, I don't remember to have ever seen one rendering with roughglass dispersion ... so I would say no, it is not worth the time.
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Re: The pink elefant

Post by B.Y.O.B. » Thu Jan 04, 2018 4:44 pm

Ok, added a note about it to the tooltips of the glass node and deactivate the dispersion socket if rough or arch glass is chosen.
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Dade
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Re: The pink elefant

Post by Dade » Thu Jan 04, 2018 7:06 pm

A beauty:
psor.png
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