   }
 }
 
-vec3 calculateLighting(vec4 color, vec3 startPos_eye, vec3 gradient)
+vec3 calculateLighting(vec4 color, vec3 currentPos_eye, vec3 gradient)
 {
   const vec3 lightPos = vec3(0.0f, 0.0f, 0.0f);
-  vec3 lightDir = normalize(lightPos - startPos_eye);
-  vec3 viewDir = -1.0f * normalize(startPos_eye);
+  vec3 lightDir = normalize(lightPos - currentPos_eye);
+  vec3 viewDir = -1.0f * normalize(currentPos_eye);
   vec3 normalizedGradient = normalize(gradient);
 
   float dotNL = max(dot(normalizedGradient, lightDir), 0.0f);

}

vec4 calculateSampleColor(in uint remainingActiveObjects, in int activeObjectCount,
    in vec4 startPos_eye)
{
  vec4 sampleColor = vec4(0.0f, 0.0f, 0.0f, 0.0f);


    vec3 textureSamplePos =
      (volumes[currentObjectId].objectToDatasetMatrix *
       volumes[currentObjectId].textureMatrix * inverseViewMatrix *
       currentPos_eye).xyz;

    float density = getVolumeSampleDensity(textureSamplePos);
    vec4 currentColor = transferFunctionLookUp(currentObjectId, density);
