title: invalid subscript 'texcoord'
body: <p>I am pretty new to Unity 3D and just trying to implement this tutorial: <a href="http://bernieroehl.com/360stereoinunity/" rel="nofollow noreferrer">http://bernieroehl.com/360stereoinunity/</a></p>
  
  <p>When creating the adapted Shader that he is describing I made a new unlit shader and input his two lines of code the <code>Cull front</code> and the <code>v.texcoord.x = 1 - v.texcoord.x;</code></p>
  
  <p>Now I get an exception </p>
  
  <blockquote>
    <p>Shader error in 'Unlit/insideOut': invalid subscript 'texcoord' at
    line 43 (on d3d11)</p>
  </blockquote>
  
  <p>Any idea what could be wrong?</p>
  
  <p>The whole shader:</p>
  
  <pre><code>Shader "Unlit/insideOut"
  {
  Properties
  {
      _MainTex ("Texture", 2D) = "white" {}
  }
  SubShader
  {
      Tags { "RenderType"="Opaque" }
      Cull front
      LOD 100
  
      Pass
      {
          CGPROGRAM
          #pragma vertex vert
          #pragma fragment frag
          // make fog work
          #pragma multi_compile_fog
  
          #include "UnityCG.cginc"
  
          struct appdata
          {
              float4 vertex : POSITION;
              float2 uv : TEXCOORD0;
          };
  
          struct v2f
          {
              float2 uv : TEXCOORD0;
              UNITY_FOG_COORDS(1)
              float4 vertex : SV_POSITION;
          };
  
          sampler2D _MainTex;
          float4 _MainTex_ST;
  
          v2f vert (appdata v)
          {
              v2f o;
              o.vertex = UnityObjectToClipPos(v.vertex);
              v.texcoord.x = 1 - v.texcoord.x;
              o.uv = TRANSFORM_TEX(v.uv, _MainTex);
              UNITY_TRANSFER_FOG(o,o.vertex);
              return o;
          }
  
          fixed4 frag (v2f i) : SV_Target
          {
              // sample the texture
              fixed4 col = tex2D(_MainTex, i.uv);
              // apply fog
              UNITY_APPLY_FOG(i.fogCoord, col);
              return col;
          }
          ENDCG
      }
  }
  }
  </code></pre>