Shader "Custom/MatterShader" 
{
            Properties {
                _CubeDay("CubeMap Day", CUBE) = "" {}
            }
            SubShader 
            {
                Tags { "Queue"="Background" "RenderType"="Background" }
                 
            LOD 200
            Cull Off
            ZWrite Off
            Pass 
            {
                CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #include "UnityCG.cginc"
             
                samplerCUBE _CubeDay;
                     
                struct v2f 
                {
                    float4  pos : SV_POSITION;
                    float3 norm : TEXCOORD0;
                };
                v2f vert (appdata_base v)
                {
                    v2f o;
                    o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                    o.norm = v.normal;
                    return o;
                }
                     
                half4 frag (v2f i) : COLOR
                {
                    return texCUBE(_CubeDay,i.norm); 
                }
                ENDCG
            }
        } 
        FallBack "Diffuse"
    }

