Luxus for Carrara and Diamond Material

kunterbunt

I'm very exited by the ability to use LuxRender from within Carrara, though I'm still just starting to learn how to use it. One of my test renders is using a diamond in the shape of a brilliant. It renders fantastically in Blender using Diamond material from the LuxRender material database. I actually used Blender to decide if I wanted to have Luxus fro Carrara. Unfortunately I cannot get the same results using Glass 2 in Carrara.
Now I have difficulties using the same material "Diamond" from within Carrara. I cannot select Diamond, because it is not one of th provided materials. I cannot select this material from LuxSurface using Material "diamond" (gives error: Static loading of material 'diamond' failed.).

Anyone has an idea how to solve this Problem?

briandaz_3e696c2bd8

Try this setup:

- Lux Surface
--- Lux Glass2
----- X Dispersion
--- Interior:Lux Clear
----- Index of refraction:Diamond

kunterbunt

That is of course what I tried. You can see the difference in the images I posted. The first image uses diamond material through Blender, th second one uses glass2 using carrara. Both of course rendered using Luxus and LuxRender. As you can see, the colored light is missing in the second one.
The diamond material defines a new interior called diam.

dtamm

kunterbunt said:

That is of course what I tried. You can see the difference in the images I posted. The first image uses diamond material through Blender, th second one uses glass2 using carrara. Both of course rendered using Luxus and LuxRender. As you can see, the colored light is missing in the second one.
The diamond material defines a new interior called diam.

What light are you using? Try deleting the default light and use a Lux SunSky2.

kunterbunt

Both use LuxRender Infinite light (HDRI).

briandaz_3e696c2bd8

I'm running a test now with a glass prism, and don't see any evidence of a rainbow. After looking through the Luxrender documents, it seems several materials are not included in the Luxus plugin, like Cauchy and Sellmeier. The documents specifically say that dispersion will not work with a constant index of refraction shader, it needs something more complicated. I also tried using the "Lux Fesnelname" shader with a .nk file for diamond, but LuxRender didn't like the file format.

Just tried the "Fresnel Color" shader with some success. Set a color with different R, G, B settings. I have no idea yet how the color value relates to IOR, so I'm not sure what the proper value for diamond is.

Edit:
Experimentally, RGB values below 100 (on a scale of 255) give weird results, so I think the value should be the IOR*100.
According to one reference I found, by this formula, try R=235, G=230, and B=226

kunterbunt

brianorca said:

I'm running a test now with a glass prism, and don't see any evidence of a rainbow. After looking through the Luxrender documents, it seems several materials are not included in the Luxus plugin, like Cauchy and Sellmeier. The documents specifically say that dispersion will not work with a constant index of refraction shader, it needs something more complicated. I also tried using the "Lux Fesnelname" shader with a .nk file for diamond, but LuxRender didn't like the file format.

Just tried the "Fresnel Color" shader with some success. Set a color with different R, G, B settings. I have no idea yet how the color value relates to IOR, so I'm not sure what the proper value for diamond is.

It looks as if luxus needs enhancement. I also found a bug. You cannot specify the number of samples per pixel at which rendering will stop. The UI value will be used as time limit.

PhilW

Instead of using Glass2, use Glass and set the "Cauchy B" value to 5-10%, this gives colour dispersion. I have attached an example, generated with a single beam of white light.

kunterbunt

PhilW said:

Instead of using Glass2, use Glass and set the "Cauchy B" value to 5-10%, this gives colour dispersion. I have attached an example, generated with a single beam of white light.

Will try this as soon as I can.