Refraction BSDF node :
A refraction shader acts like glass but without the reflections. Light passing through it will get tinted, bent and scattered. The transparency of the shader is dependent on the color value (lightness) and the modulation (hue / saturation) will influence the tint of light passing through
the object.
A refraction shader with IOR 1.0 will look like a transparent BSDF but rays passing through it are actually transmission rays.
The refraction shader should be mixed with a glossy shader with a Fresnel value for the factor for best results. This way
you get a glass material, where you can influence the glossy and the transmission values separately.
This material comes in three modes:
Beckmann :
Standard method for calculating glossy or refractive surfaces in computer graphics. It comes with a rough slider to control how blurry transmissions will appear.
GGX :
The differences between Beckmann and GGX are fairly small. We found that GGX produces a bit more noisy and less detailed blurs, while render times are almost identical. Also this mode seems to brighten surfaces with normals pointing further away from the camera.
Sharp :
In this mode the roughness slider will not make any difference, however, if you know you are going to use a transparent material that does bend light, this mode will compute faster than Beckmann or GGX.
Color :
Input for an RGB or a texture.


#blender
#refraction
#bsdf
#node

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