 
     // now map through opacity and color
     tColor = getColorForValue(value, posIS, tstep);
-
-    // compute the normal if needed
-    //VTK::Normal::Impl
-
-    // handle gradient opacity
-    //VTK::GradientOpacity::Impl
-
-    // handle lighting
-    //VTK::Light::Impl
 
     gl_FragData[0] = tColor;
   #endif

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

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

      // Perform the last step along the ray using the

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

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

    // Perform the last step along the ray using the
