Glass BSDF¶
The Glass BSDF is used to add a Glass-like shader mixing refraction and reflection at grazing angles. Like the transparent shader, only pure white will make it transparent. The glass shader tends to cause noise due to caustics. Since the Cycles path tracing integrator is not very good at rendering caustics, it helps to combine this with a transparent shader for shadows; for more details see here.
Inputs¶
- Color
Color of the surface, or physically speaking, the probability that light is transmitted for each wavelength.
- Roughness
Influences sharpness of the refraction; perfectly sharp at 0.0 and smoother with higher values.
- IOR
Index of refraction (IOR) defining how much the ray changes direction. At 1. 0 rays pass straight through like transparent; higher values give more refraction.
- Normal
Normal used for shading.
Thin Film Cycles Only¶
Thin Film simulates the effect of interference in a thin film sitting on top of the material. This causes the specular reflection to be colored in a way which strongly depends on the view angle as well as the film thickness and the index of refraction (IOR) of the film and the material itself.
This effect is commonly seen on e.g. oil films, soap bubbles or glass coatings. While its influence is more obvious in specular highlights, it also affects transmission.
- Thickness
The thickness of the film in nanometers. A value of 0 disables the simulation. The interference effect is strongest between roughly 100 and 1000 nanometers, since this is near the wavelengths of visible light.
- IOR
Index of refraction (IOR) of the thin film. The common range for this value is between 1.0 (vacuum and air) and roughly 2.0, though some materials can reach higher values. The default value of 1.33 is a good approximation for water. Note that when the value is set to 1.0 or to the main IOR of the material, the thin film effect disappears since the film optically blends into the air or the material.
Properties¶
- Distribution
Microfacet distribution to use.
- GGX:
GGX microfacet distribution.
- Multiscatter GGX:
Takes multiple scattering events between microfacets into account. This gives more energy conserving results, which would otherwise be visible as excessive darkening.
- Beckmann:
Cycles Only Beckmann microfacet distribution.
Outputs¶
- BSDF
Standard shader output.
