diff --git a/src/consts.cu b/src/consts.cu
index 415d3f4..69235dd 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
@@ -84,6 +76,8 @@ __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 dfcf1f4..f303c5e 100644
--- a/src/consts.h
+++ b/src/consts.h
@@ -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/MainWindow.cpp b/src/gui/MainWindow.cpp
index 8f19b1b..9ab73a5 100644
--- a/src/gui/MainWindow.cpp
+++ b/src/gui/MainWindow.cpp
@@ -92,7 +92,6 @@ void Window::free(float* data) {
 
 
 void Window::tick() {
-  std::cout << "tick tick\n";
   // manually track time diff
 	std::chrono::steady_clock::time_point now = std::chrono::steady_clock::now();
   float diff = (float) std::chrono::duration_cast<std::chrono::milliseconds>(now - this->last_frame).count();
@@ -101,12 +100,10 @@ void Window::tick() {
   // input
   this->widget->tick(1000.0/diff);
   
-  std::cout << "setting tick render\n";
   // tick render
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 	glDisable(GL_DEPTH_TEST);
 
-  std::cout << "blabla\n";
   if (!this->widget->paused) this->quad->render();
   this->shader->use();
 	glBindVertexArray(this->quad->VAO);
@@ -114,14 +111,11 @@ void Window::tick() {
 	glDrawArrays(GL_TRIANGLES, 0, 6); // draw current frame to texture
   
   // render ImGui context
-  std::cout << "rendering\n";
   this->widget->render();
-  std::cout << "done rendering\n";
 
   // check for events
 	glfwSwapBuffers(this->window);
 	glfwPollEvents();
-  std::cout << "done tick tick\n";
 
 }
 
diff --git a/src/gui/input/Widget.cpp b/src/gui/input/Widget.cpp
index b03a795..daa5856 100644
--- a/src/gui/input/Widget.cpp
+++ b/src/gui/input/Widget.cpp
@@ -45,9 +45,12 @@ Widget::Widget(GLFWwindow* window) {
   this->sigmoidExp = -250.0f;
   this->alphaAcumLimit = 0.4f;
   this->tfComboSelected = 2;
+  this->tfComboSelectedColor = 0;
   this->opacityConst = 100;
   this->showSilhouettes = false;
   this->silhouettesThreshold = 0.02f;
+  this->levoyFocus = 0.5;
+  this->levoyWidth = 1;
 };
 
 // REFACTOR: should probably not have all the logic in one function; something like a list of ImplementedWidgets with each a Render() function (a la interface) would be better.
@@ -73,13 +76,18 @@ void Widget::tick(double fps) {
   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;
@@ -171,11 +179,14 @@ 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));
 
   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 34799c4..a28a718 100644
--- a/src/gui/input/Widget.h
+++ b/src/gui/input/Widget.h
@@ -32,6 +32,8 @@ public:
   float opacityConstReal;
   bool showSilhouettes;
   float silhouettesThreshold;
+  float levoyFocus;
+  float levoyWidth;
 
   ImGuiIO io;
 
diff --git a/src/illumination/transferFunction.cu b/src/illumination/transferFunction.cu
index 6fc6fc8..72dd27b 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