Documentation→ReferenceIngredients→Surface/Specular





The specular ingredient reflects lights and Reflection Probes, and mixes it with proper fresnel handling.

Its type can be changed between The Greatest Sandwich, Unity Standard, Standard, Circular, and Wave by using the side arrows next to the preview image.

The specular ingredient can have custom lighting enabled by toggling the two buttons on the top right - the light bulb enables custom direct light, and the indirect lighting box enables custom indirect light. Custom lighting can either be completely overridden, or altered using layers with the type Adjustment.
Global-ish options:

Specular or Metal - Work with either the specular workflow - where the Specular layer channel colors the specular and controlls how metallic the surface is; or the metallic one - where the Albedo layer channel colors the specular and the Metallness layer channel controls how metallic the surface is.

Smoothness/Roughness - How smooth/rough the surface is; a rougher surface has more microscopic groves and dents.

Light Radius - Sets the light radius...

Offset - Rotates the specular highlights around the surface.

Use Ambient - When off ambient and indirect lighting is disabled.

Use Tangents - Instead of using the normal vector (that points directly out of the surface) for lighting calculations, use the tangent vector (that points along the x-axis of the texture) instead - can be useful for hair and grass if used right.

Use Fresnel - Turn off to disregard the fresnel effect - the increase in specular at grazing angles.

Conserve Energy (Standard, Circular and Wave) - Ensures energy is properly distributed across different smoothnesses, as rougher surface lead to a dimmer highlight in reality (since the energy is spread over a larger area), and vice versa.


The Greatest Sandwich ...shader model
Has a more realistic and energy conserving fresnel, more accurate roughness occlusion, has a lower base metallic reflectance, and is faster.
Micro Occlusion - Whether the surface should self occlude/darken at higher roughnesses.
Unity Standard
Unity's standard brdf.
Standard
A very simple lighting model with a sharper fall-off.
Circular
Honestly I have no idea/can't remember...just looks kinda weird.
Wave
A pretty cool looking wave like highlight that could be used for electricity or caustics for example.