glass (newbie question)

[jon]

Hi All,

Just started playing with LuxCore ... it's amazing . Thanks to the development team for all the hard work!

Quick question about glass. I tried creating a simple glass material and applying it to a sphere (foreground) and, well, I failed.

Material is defined as:

Code: Select all

scene.materials.glass_test.type = glass
scene.materials.glass_test.kr = 0.2 0.2 0.2
scene.materials.glass_test.kt = 0.5 0.5 0.5

Should there not be specular reflections? Clearly I've missed something obvious. Can someone steer me in the right direction?

Cheers,

Jon

PS. Not trying to do volume rendering here -- just a thin glass surface.

[Dade]

You need to define the glass index of refraction (aka IOR) with the property ".inetriorior": https://github.com/LuxCoreRender/LuxCor ... ll.scn#L23

[jon]

Ah, got it, thanks. I'd assumed the default value (1.5) would take effect.

Follow up question: What's the physical meaning of kr and kt? I assume kr is a multiplier that acts on the specular-reflection component (which is determined by IORs)? And kt acts on the non-reflected remainder? Just want to make sure I understand the physical basis. (I can also check the source code if this isn't documented elsewhere .)

[Dade]

Follow up question: What's the physical meaning of kr and kt? I assume kr is a multiplier that acts on the specular-reflection component (which is determined by IORs)? And kt acts on the non-reflected remainder? Just want to make sure I understand the physical basis. (I can also check the source code if this isn't documented elsewhere .)

They are the specular reflection and transmission scale factors. You can set both to (1.0, 1.0, 1.0) for a perfect specular transmission/reflection without any kind of attenuation.

[jon]

Perfect. Thanks, Dade.