Surface Shader 筆記 4. Lighting - Lighting Model and SurfaceOutput

光照模型和 Surface Output 使用不同的光照模型，會允許 SurfaceOutput使用額外的輸出值

Light Model [參照筆記 4. Lighting - Lighting Model]

模型 Lambert

#pragma surface surf Lambert

void surf (Input IN,inout SurfaceOutput o) { o.Albedo = _Colour.rgb; }

模型 Blinn - Phong 允許鏡面反射值 (Specular)和光澤度 (Gloss)

#pragma surface surf BlinnPhong _SpecColor (“Colour”,Color) = (1,1,1,1) _Spec (“Specular”, Range(0,1)) = 0.5 _Gloss (“Gloss”, Range(0,1)) = 0.5

void surf (Input IN,inout SurfaceOutput o) { o.Albedo = _Colour.rgb; o.Specular = _Spec; o.Gloss = _Gloss; } 註: 屬性 _SpecColor，被定義在 Unity文件中，為 BlinnPhong的高光顏色，不能再次定義也不需要再指定給 SurfaceOutupt，宣告屬性即有效果

模型 Standard (PBR) 允許使用金屬值 (Metallic)和平滑度 (Smoothness)

#pragma surface surf Standard _Metallic (“Metallic” , Range(0,1)) = 0.0

void surf (Input IN, inout SurfaceOutputStandard o) { o.Albedo = _Color.rgb; o.Smoothness = tex2D (_MetallicTex,IN.uv_MetallicTex).r; o.Metallic = _Metallic;
}

模型 StandardSpecular (PBR) 允許鏡面反射值 (Specular)和平滑度 (Smoothness)

#pragma surface surf StandardSpecular

_MetallicTex (“Metallic (R)”, 2D) = “white” { } _SpecColor (“Specular” , Color) = (1,1,1,1) void surf (Input IN, inout SurfaceOutputStandardSpecular o) { o.Albedo = _Color.rgb; o.Smoothness = tex2D (_MetallicTex,IN.uv_MetallicTex).r; o.Specular = _SpecColor.rgb;
}

註: Unity 有預設的兩種使用物理渲染照明 (PBR)的材質球 Standard 和 Standard (Specular setup)