The Eye material is used to render character eyes, eyeballs, iris and pupil. The material simulates a refraction over the cornea, and models the iris a cone section.his material doesn't require any specific geometry and fits very well to non spherical eyeballs, as is commonly used on CG characters.
This section documents the most common eye features, but many more can be found direction on the Eye material
and RenderGraph node.
Iris controlIris Color
The iris diffuse color. Note: this value is multiplied by the iris color texture.
The iris size, expressed as an angle from the eye front direction to the iris center to edge direction.
The iris width/height, used to render non circular iris.
The iris depth, used to increase the preception of the eye volume.
Pupil controlPupil Size
The pupil size, relative to the iris size.
The pupil width/height, used to render non circular pupil.
Cornea controlCornea Roughness
The cornea specular roughness.
Cornea Spec IOR
The cornea index of refraction used to compute specular blending. The higher this value, the stronger the specular reflection.
Cornea Refraction IOR
The cornea index of refraction used to compute refracted direction inside the cornea. This value has a direct effect on the perception of the pupil. The higher this value, the more deformed the pupil will look seen from the side of the eye ball
For artistic reasons, it is usually convenient to decouple highlight rendering from the actual eye lighting. The eye shader features a specifically deterministic and non physical highlight, which is controlled by its position relative to the iris edge. To activate this highlight, simply set the highlight size to any non zero value.Highlight Size
The highlight size.
Controls where the highlight is located around the iris. 0 is the up direction
Controls where the highlight is located to the iris edge. 0 is the iris edge
Textures are laid out as polar maps, inner edge at the bottom and outer edge at the top.
By default, the eye material expects the eyeball geometry to be centered on its origin. The X local axis is the main eye direction, while the Y local axis is the up direction. You can adjust these values values directly in the General tab of the material parameters.