Demo 58 - Lambert diffuse per vertex

Shader "Custom/Lighting/VertexLambertDiffuse"
{
    Properties
    {
        _Color ("Color", Color) = (1.0, 1.0, 1.0, 1.0)
        _Diffuse ("Diffuse value", Range(0, 1)) = 1.0
    }
    SubShader
    {
        Tags { "LightMode"="ForwardBase" }

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

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

            struct v2f {
                float4 pos : SV_POSITION;
                fixed4 col : COLOR0;
            };

            fixed4 _Color;
            fixed4 _LightColor0;
            float _Diffuse;

            v2f vert(appdata v) {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                float3 worldNormal = normalize(mul(v.normal, (float3x3)unity_WorldToObject));
                float3 lightDir = normalize(_WorldSpaceLightPos0.xyz);
                float NdotL = max(0.0, dot(worldNormal, lightDir));
                fixed4 diff = _Color * NdotL * _LightColor0 * _Diffuse;
                o.col = diff;
                return o;
            }

            float4 frag(v2f i) : SV_Target {
                return i.col;
            }

            ENDCG
        }
    }
}