     // handle lighting
     //VTK::Light::Impl
 
-    gl_FragData[0] = tcolor;
+    gl_FragData[0] = tColor;
   #endif
 }
 

    for (i = 0; i < //VTK::MaximumSamplesValue ; ++i)
    {
      // compute the scalar
      scalar = getTextureValue(posIS).r;

      // One can control the scalar range by setting the AverageIPScalarRange to disregard scalar values, not in the range of interest, from the average computation
      if (scalar < averageIPScalarRangeMin || scalar > averageIPScalarRangeMax) {
        continue;
      }

      // Average intensity blend mode works similar to the additive blend mode where the scalar values are multiplied by opacity calculated from the opacity transfer function and then added
      computed = texture2D(otexture, vec2(scalar * oscale0 + oshift0, 0.5)).r;

      // Sum the values across each step in the path
      value += computed;

      posIS += stepIS;
      if (i >= count) { break; }

      for (int i = 0; i < //VTK::MaximumSamplesValue ; ++i)
      {
        // compute the scalar
        tValue = getTextureValue(posIS);

        // Update the maximum value if necessary
        value = max(tValue, value);

        posIS += stepIS;
        if (i >= count) { break; }
