Using a vertex modifier function, it is also possible to compute custom data in a vertex ShaderA program that runs on the GPU. More info
See in Glossary, which then will be passed to the Surface ShaderA streamlined way of writing shaders for the Built-in Render Pipeline. More info
See in Glossary function per-pixel. The same compilation directive vertex:functionName
is used, but the function should take two parameters: inout appdata_full
and out Input
. You can fill in any Input member that is not a built-in value there.
Note: Custom Input members used in this way must not have names beginning with ‘uv’ or they won’t work properly.
The example below defines a custom float3 customColor
member, which is computed in a vertex function:
Shader "Example/Custom Vertex Data" {
Properties {
_MainTex ("Texture", 2D) = "white" {}
}
SubShader {
Tags { "RenderType" = "Opaque" }
CGPROGRAM
#pragma surface surf Lambert vertex:vert
struct Input {
float2 uv_MainTex;
float3 customColor;
};
void vert (inout appdata_full v, out Input o) {
UNITY_INITIALIZE_OUTPUT(Input,o);
o.customColor = abs(v.normal);
}
sampler2D _MainTex;
void surf (Input IN, inout SurfaceOutput o) {
o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
o.Albedo *= IN.customColor;
}
ENDCG
}
Fallback "Diffuse"
}
In this example customColor
is set to the absolute value of the normal:
More practical uses could be computing any per-vertex data that is not provided by built-in Input variables; or optimizing Shader computations. For example, it’s possible to compute Rim lighting at the GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary’s vertices, instead of doing that in the Surface Shader per-pixel.