How to make curve shader support light and shadow ?

[Warville]

hey guys , i’m working on a endless running game, i have a basic world bending / curve shader that does the same effect as in Subway surfer to make the road looks curved , it work fine but it doesn’t support light and shadow , the light in the scene only have effect on the character because it doesn’t use the same shader as you can see below in the picture, can you helpe me modefy this shader to make it works fine with lights?

    Shader "Custom/Curved" {
        Properties {
            _MainTex ("Base (RGB)", 2D) = "white" {}
            _QOffset ("Offset", Vector) = (0,0,0,0)
            _Dist ("Distance", Float) = 100.0
        }
        SubShader {
            Tags { "RenderType"="Opaque" }
            Pass
            {
                CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #include "UnityCG.cginc"
     
                sampler2D _MainTex;
                float4 _QOffset;
                float _Dist;
               
                struct v2f {
                    float4 pos : SV_POSITION;
                    float4 uv : TEXCOORD0;
                };
     
                v2f vert (appdata_base v)
                {
                    v2f o;
                    float4 vPos = mul (UNITY_MATRIX_MV, v.vertex);
                    float zOff = vPos.z/_Dist;
                    vPos += _QOffset*zOff*zOff;
                    o.pos = mul (UNITY_MATRIX_P, vPos);
                    o.uv = mul( UNITY_MATRIX_TEXTURE0, v.texcoord );
                    return o;
                }
     
                half4 frag (v2f i) : COLOR
                {
                    half4 col = tex2D(_MainTex, i.uv.xy);
                    return col;
                }
                ENDCG
            }
        }
        FallBack "Diffuse"
    }

[tanoshimi]

The easiest way to create a shader that accounts for lighting is to write a Surface shader, instead of a vertex/fragment shader as you have done. You should be able to move the curve function into the vertex modifier of a surface shader without too many adjustments.