diff --git a/src/consts.cu b/src/consts.cu
index 415d3f4..5b7159c 100644
--- a/src/consts.cu
+++ b/src/consts.cu
@@ -2,41 +2,33 @@
 #include "cuda_error.h"
 
 // ----------------------- Colour mapping -----------------------
-// __device__ __constant__ ColorStop d_stopsPythonLike[5];
-__device__ __constant__ ColorStop d_stopsPythonLike[11];
+__device__ __constant__ ColorStop d_stopsPythonLike[5];
+// __device__ __constant__ ColorStop d_stopsPythonLike[11];
 __device__ __constant__ ColorStop d_stopsGrayscale[2];
 __device__ __constant__ ColorStop d_stopsBluePurleRed[3];
 
-// const ColorStop h_stopsPythonLike[] = {
-//         { 0.0f, Color3::init(0.2298057f, 0.29871797f, 0.75368315f) }, // Dark Blue
-//         { 0.25f, Color3::init(0.23437708f, 0.30554173f, 0.75967953f) }, // Mid Blue
-//         { 0.5f, Color3::init(0.27582712f, 0.36671692f, 0.81255294f) }, // White
-//         { 0.75f, Color3::init(0.79606387f, 0.84869321f, 0.93347147f) }, // Light Orange
-//         { 1.0f, Color3::init(0.70567316f, 0.01555616f, 0.15023281f) }  // Red
-// };
-
-// const ColorStop h_stopsPythonLike[] = {
-//         { 0.0f, Color3::init(0.2298057f, 0.29871797f, 0.75368315f) }, // Dark Blue
-//         { 0.85f, Color3::init(0.23437708f, 0.30554173f, 0.75967953f) }, // Mid Blue
-//         { 0.90f, Color3::init(0.27582712f, 0.36671692f, 0.81255294f) }, // White
-//         { 0.95f, Color3::init(0.79606387f, 0.84869321f, 0.93347147f) }, // Light Orange
-//         { 1.0f, Color3::init(0.70567316f, 0.01555616f, 0.15023281f) }  // Red
-// };
+const ColorStop h_stopsPythonLike[] = {
+        { 0.0f, Color3::init(0.2298057f, 0.29871797f, 0.75368315f) }, // Dark Blue
+        { 0.25f, Color3::init(0.23437708f, 0.30554173f, 0.75967953f) }, // Mid Blue
+        { 0.5f, Color3::init(0.27582712f, 0.36671692f, 0.81255294f) }, // White
+        { 0.75f, Color3::init(0.79606387f, 0.84869321f, 0.93347147f) }, // Light Orange
+        { 1.0f, Color3::init(0.70567316f, 0.01555616f, 0.15023281f) }  // Red
+};
 
 // Python "jet" colour scheme
-const ColorStop h_stopsPythonLike[] = {
-    { 0.00f, Color3::init(0.00000000f, 0.00000000f, 0.50000000f) },
-    { 0.82f, Color3::init(0.00000000f, 0.00000000f, 0.94563280f) },
-    { 0.84f, Color3::init(0.00000000f, 0.30000000f, 1.00000000f) },
-    { 0.86f, Color3::init(0.00000000f, 0.69215686f, 1.00000000f) },
-    { 0.88f, Color3::init(0.16129032f, 1.00000000f, 0.80645161f) },
-    { 0.90f, Color3::init(0.49019608f, 1.00000000f, 0.47754586f) },
-    { 0.92f, Color3::init(0.80645161f, 1.00000000f, 0.16129032f) },
-    { 0.94f, Color3::init(1.00000000f, 0.77051561f, 0.00000000f) },
-    { 0.96f, Color3::init(1.00000000f, 0.40740741f, 0.00000000f) },
-    { 0.98f, Color3::init(0.94563280f, 0.02977487f, 0.00000000f) },
-    { 1.00f, Color3::init(0.50000000f, 0.00000000f, 0.00000000f) },
-};
+// const ColorStop h_stopsPythonLike[] = {
+//     { 0.00f, Color3::init(0.00000000f, 0.00000000f, 0.50000000f) },
+//     { 0.82f, Color3::init(0.00000000f, 0.00000000f, 0.94563280f) },
+//     { 0.84f, Color3::init(0.00000000f, 0.30000000f, 1.00000000f) },
+//     { 0.86f, Color3::init(0.00000000f, 0.69215686f, 1.00000000f) },
+//     { 0.88f, Color3::init(0.16129032f, 1.00000000f, 0.80645161f) },
+//     { 0.90f, Color3::init(0.49019608f, 1.00000000f, 0.47754586f) },
+//     { 0.92f, Color3::init(0.80645161f, 1.00000000f, 0.16129032f) },
+//     { 0.94f, Color3::init(1.00000000f, 0.77051561f, 0.00000000f) },
+//     { 0.96f, Color3::init(1.00000000f, 0.40740741f, 0.00000000f) },
+//     { 0.98f, Color3::init(0.94563280f, 0.02977487f, 0.00000000f) },
+//     { 1.00f, Color3::init(0.50000000f, 0.00000000f, 0.00000000f) },
+// };
 
 const ColorStop h_stopsGrayscale[] = {
         { 0.0f, Color3::init(0.0f, 0.0f, 0.0f) },  // No colour
@@ -56,6 +48,8 @@ __device__ Vec3 d_cameraDir;
 __device__ Point3 d_lightPos;
 __device__ Color3 d_backgroundColor;
 __device__ Vec3 d_cameraUp;
+__device__ double d_specularStrength;
+__device__ int d_shininess;
 
 Vec3 h_cameraUp = Vec3::init(0.0, 1.0, 0.0).normalize();
 
@@ -84,6 +78,8 @@ __device__ int d_tfComboSelectedColor;
 __device__ float d_opacityConst;
 __device__ bool d_showSilhouettes;
 __device__ float d_silhouettesThreshold;
+__device__ float d_levoyFocus;
+__device__ float d_levoyWidth;
 
 // ----------------------- Raycasting -----------------------
 __device__ int d_samplesPerPixel;
diff --git a/src/consts.h b/src/consts.h
index 5457594..29f23f3 100644
--- a/src/consts.h
+++ b/src/consts.h
@@ -41,8 +41,8 @@ const float stepSize = 0.02f;
 // Shading consts
 const double ambientStrength  = 0.3;
 const double diffuseStrength  = 0.8;
-const double specularStrength = 0.5;
-const int shininess           = 32;
+extern __device__ double d_specularStrength; // = 0.5;
+extern __device__ int d_shininess; //           = 32;
 const float fov             = 60.0f * (M_PI / 180.0f);
 
 // Camera and Light
@@ -78,11 +78,14 @@ extern __device__ int d_samplesPerPixel;
 // Silhouettes
 extern __device__ bool d_showSilhouettes;
 extern __device__ float d_silhouettesThreshold;
+// controlling levoy opacity function
+extern __device__ float d_levoyFocus;
+extern __device__ float d_levoyWidth;
 
-const int lenStopsPythonLike = 11;
+const int lenStopsPythonLike = 5;
 const int lenStopsGrayscale = 2;
 const int lenStopsBluePurpleRed = 3;
-extern __constant__ ColorStop d_stopsPythonLike[11];
+extern __constant__ ColorStop d_stopsPythonLike[5];
 extern __constant__ ColorStop d_stopsGrayscale[2];
 extern __constant__ ColorStop d_stopsBluePurleRed[3];
 
diff --git a/src/gui/input/Widget.cpp b/src/gui/input/Widget.cpp
index 2c6a19d..f38d403 100644
--- a/src/gui/input/Widget.cpp
+++ b/src/gui/input/Widget.cpp
@@ -98,18 +98,25 @@ void Widget::tick(double fps) {
   
 
   ImGui::Begin("Transfer Function Controls");
+  ImGui::DragFloat("Specular Strength", &this->specularStrength, 0.01f, 0.0f, 1.0f, "%.2f");
+  ImGui::DragInt("Shininess", &this->shininess, 1, 1, 64, "%d", ImGuiSliderFlags_AlwaysClamp);
   ImGui::DragInt("Grad. exp. (log [1e-10, 1])", &this->opacityK, 1, 0, 100, "%d%%", ImGuiSliderFlags_AlwaysClamp);
   ImGui::DragFloat("Sig. shift", &this->sigmoidShift, 0.01f, 0.0f, 1.0f, "%.2f");
   ImGui::InputFloat("Sig. sxp", &this->sigmoidExp, 10.0f, 100.0f, "%.0f");
   ImGui::DragFloat("Alpha accum. limit", &this->alphaAcumLimit, 0.01f, 0.0f, 1.0f, "%.2f");
   ImGui::DragInt("Opacity const. (log [1e-5, 1])", &this->opacityConst, 1, 0, 100, "%d%%", ImGuiSliderFlags_AlwaysClamp);
+  ImGui::DragFloat("Levoy Width", &this->levoyWidth, 0.01f, 0.0f, 100.0f, "%.2f");
+  // ImGui::DragFloat("Levoy Focus", &this->levoyFocus, 0.01f, 250.0f, 350.0f, "%.2f");
+  ImGui::DragFloat("Levoy Focus", &this->levoyFocus, 0.01f, 0.0f, 1.0f, "%.2f");
   
   // the items[] contains the entries for the combobox. The selected index is stored as an int on this->tfComboSelected
   // the default entry is set in the constructor, so if you want that to be a specific entry just change it
   // whatever value is selected here is available on the gpu as d_tfComboSelected.
-  const char* items[] = {"Opacity - gradient", "Opacity - sigmoid", "Opacity - constant", "..."};
+  const char* items[] = {"Opacity - gradient", "Opacity - sigmoid", "Opacity - constant", "Opacity - levoy"};
   if (ImGui::BeginCombo("Transfer function", items[this->tfComboSelected])) {
+    // std::cout << "hello???\n";
     for (int n = 0; n < IM_ARRAYSIZE(items); n++) {
+      // std::cout << "letsssssa a asdfa???\n";
       const bool is_selected = (this->tfComboSelected == n);
       if (ImGui::Selectable(items[n], is_selected))
         this->tfComboSelected = n;
@@ -228,11 +235,17 @@ void Widget::copyToDevice() {
   cudaMemcpyToSymbol(&d_tfComboSelected, &this->tfComboSelected, sizeof(int));
   cudaMemcpyToSymbol(&d_showSilhouettes, &this->showSilhouettes, sizeof(bool));
   cudaMemcpyToSymbol(&d_silhouettesThreshold, &this->silhouettesThreshold, sizeof(float));
+  cudaMemcpyToSymbol(&d_levoyFocus, &this->levoyFocus, sizeof(float));
+  cudaMemcpyToSymbol(&d_levoyWidth, &this->levoyWidth, sizeof(float));
+  double specularStrengthDouble = this->specularStrength;
+  cudaMemcpyToSymbol(&d_specularStrength, &specularStrengthDouble, sizeof(double));
+  cudaMemcpyToSymbol(&d_shininess, &this->shininess, sizeof(int));
 
   this->opacityConstReal = std::pow(10.0f, (-5 + 0.05 * this->opacityConst));
   cudaMemcpyToSymbol(&d_opacityConst, &this->opacityConstReal, sizeof(float));
 
   cudaMemcpyToSymbol(&d_tfComboSelectedColor, &this->tfComboSelectedColor, sizeof(int));
+
 }
 
 Widget::~Widget() {
diff --git a/src/gui/input/Widget.h b/src/gui/input/Widget.h
index 58e69e7..39ed587 100644
--- a/src/gui/input/Widget.h
+++ b/src/gui/input/Widget.h
@@ -46,6 +46,10 @@ private:
   float opacityConstReal;
   bool showSilhouettes;
   float silhouettesThreshold;
+  float levoyFocus;
+  float levoyWidth;
+  float specularStrength;
+  int shininess;
 
   // miscellaneous
   Point3 lightPos;
diff --git a/src/illumination/shading.cu b/src/illumination/shading.cu
index 8fa8970..f2d067e 100644
--- a/src/illumination/shading.cu
+++ b/src/illumination/shading.cu
@@ -6,8 +6,8 @@ __device__ Vec3 phongShading(const Vec3& normal, const Vec3& lightDir, const Vec
     Vec3 diffuse = baseColor * (diffuseStrength * diff);
 
     Vec3 reflectDir = (normal * (2.0 * normal.dot(lightDir)) - lightDir).normalize();
-    double spec = pow(fmax(viewDir.dot(reflectDir), 0.0), shininess);
-    Vec3 specular = Vec3::init(1.0, 1.0, 1.0) * (specularStrength * spec);
+    double spec = pow(fmax(viewDir.dot(reflectDir), 0.0), d_shininess);
+    Vec3 specular = Vec3::init(1.0, 1.0, 1.0) * (d_specularStrength * spec);
 
     return ambient + diffuse + specular;
 };
diff --git a/src/illumination/transferFunction.cu b/src/illumination/transferFunction.cu
index 6fc6fc8..1775af3 100644
--- a/src/illumination/transferFunction.cu
+++ b/src/illumination/transferFunction.cu
@@ -3,10 +3,29 @@
 
 #include <stdio.h>
 
+// [Levoy 1988]
+__device__ float levoyOpacity(const Vec3 &grad, float val) {
+    float r = d_levoyWidth; // width
+    float fv = d_levoyFocus; // chosen value
+    float epsilon = 1E-8;
+    float gradMag = grad.length();
+    if ((gradMag < epsilon) && ((val - epsilon) <= fv) && (fv <= (val + epsilon))) return 1.0f;
+    if (gradMag < epsilon) return 0.0f;
+    float lowBound = val - r*gradMag;
+    float upperBound = val + r*gradMag;
+    // float lowBound = fv - r;
+    // float upperBound = fv + r;
+    if (!((lowBound <= fv) && (fv <= upperBound))) return 0.0f;
+    // if ((lowBound <= gradMag) && (gradMag <= upperBound)) return 1.0f;
+    // return 0.0f;
 
+    float alpha = d_opacityConst*(1 - (1/r)*fabs((fv-val)/gradMag));
+    return alpha;
+}
 
 __device__ float opacityFromGradient(const Vec3 &grad, const Vec3& rayDir) {
     float gradMag = grad.length();
+    // float gradMag = 1-fabs(grad.normalize().dot(rayDir));
     // float gradMag = grad.length()*(1-fabs(grad.normalize().dot(rayDir)));  // Alternative, but not particularly better
     float alpha = 1.0f - expf(-d_opacityK * gradMag);
     return alpha;
@@ -83,6 +102,10 @@ __device__ float4 transferFunction(float density, const Vec3& grad, const Point3
   case 2:
     alpha = d_opacityConst;
     break;
+
+  case 3:
+    alpha = levoyOpacity(grad, normDensity);
+    break;
   
   default:
     alpha = 1.0f;  // This should not be reached anyway
@@ -111,8 +134,8 @@ __device__ float4 transferFunction(float density, const Vec3& grad, const Point3
     result.x = 0.0f;
     result.y = 0.0f;
     result.z = 0.0f;
-    // result.w = alpha;
-    result.w = d_opacityConst;
+    result.w = alpha;
+    // result.w = d_opacityConst;
   }
 
   return result;