Lambertian.shader

Shader "Unlit/Lambertian"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" 
            "LightMode" = "ForwardBase"
            
        }


        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            # include "UnityCG.cginc"
            # include "Lighting.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                float3 normal : NORMAL;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                float3 normal : TEXCOORD1;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                o.normal = UnityObjectToWorldNormal(v.normal);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv);
                float3 normal = i.normal;
                float3 lightDir = _WorldSpaceLightPos0.xyz;
                float3 lambertian = saturate(dot(normal, lightDir));
                return float4(lambertian * _LightColor0 * col, 1.0);
            }
            ENDCG
        }
    }
}