From 23359f9f54b07b47d760289a1d7c6a785bc90361 Mon Sep 17 00:00:00 2001
From: djairoh <ljxjah@mykolab.com>
Date: Tue, 28 May 2024 17:59:54 +0200
Subject: [PATCH] feat: swappable colour schemes

---
 particle-track-and-trace/src/CMakeLists.txt   |   2 +
 particle-track-and-trace/src/Program.cpp      |  30 ++-
 particle-track-and-trace/src/Program.h        |   8 +-
 .../src/QT/MainWindow.cpp                     |  22 +-
 .../src/advection/UVGrid.cpp                  |   6 +
 .../src/advection/UVGrid.h                    |   8 +
 .../src/commands/SpawnPointCallback.cpp       |   6 +
 .../src/commands/SpawnPointCallback.h         |   2 +
 .../src/layers/EColLayer.cpp                  | 142 ++++++------
 .../src/layers/EColLayer.h                    |  46 +++-
 .../src/layers/LColLayer.cpp                  |   8 +
 .../src/layers/LColLayer.h                    |   1 +
 .../src/layers/LGlyphLayer.cpp                | 124 +++++------
 .../src/layers/LGlyphLayer.h                  |  15 +-
 particle-track-and-trace/src/layers/Layer.cpp |   3 +-
 particle-track-and-trace/src/layers/Layer.h   |   3 +-
 .../src/layers/Technique.cpp                  |   4 +-
 .../src/layers/Technique.h                    |   3 +-
 particle-track-and-trace/src/layers/enums.h   |   3 +-
 particle-track-and-trace/src/layers/luts.cpp  | 205 ++++++++++++++++++
 particle-track-and-trace/src/layers/luts.h    |  20 ++
 21 files changed, 491 insertions(+), 170 deletions(-)
 create mode 100644 particle-track-and-trace/src/layers/luts.cpp
 create mode 100644 particle-track-and-trace/src/layers/luts.h

diff --git a/particle-track-and-trace/src/CMakeLists.txt b/particle-track-and-trace/src/CMakeLists.txt
index d024cdc..fcd6180 100644
--- a/particle-track-and-trace/src/CMakeLists.txt
+++ b/particle-track-and-trace/src/CMakeLists.txt
@@ -59,6 +59,8 @@ add_executable(ParticleTrackTrace MACOSX_BUNDLE main.cpp
         layers/Technique.cpp
         layers/Technique.h
         layers/enums.h
+        layers/luts.cpp
+        layers/luts.h
         Program.cpp
         Program.h
         commands/TimerCallbackCommand.h
diff --git a/particle-track-and-trace/src/Program.cpp b/particle-track-and-trace/src/Program.cpp
index 2802d43..a0c3232 100644
--- a/particle-track-and-trace/src/Program.cpp
+++ b/particle-track-and-trace/src/Program.cpp
@@ -57,7 +57,7 @@ Program::Program(QWidget *parent): QVTKOpenGLNativeWidget(parent) {
   setRenderWindow(this->win);
   this->interact = win->GetInteractor();
   this->cam = createNormalisedCamera();
-  this->activeIdx = -1;
+  this->activeTech = NOTECH;
 
   this->win->SetNumberOfLayers(0);
   setWinProperties();
@@ -75,38 +75,44 @@ void Program::removeTechnique(Technique *technique) {
   auto it = std::find(this->techniques.begin(), this->techniques.end(), technique);
   if (it != this->techniques.end()) {
     int idx = it - this->techniques.begin();
-    if (idx == this->activeIdx) {
+    if (idx == this->activeTech) {
       throw std::out_of_range("Can't remove active technique.");
     }
     this->techniques.erase(it);
-    this->activeIdx = -1;
-    setActiveTechnique(0);
+    this->activeTech = NOTECH;
+    setActiveTechnique(COLGLYPH);
   }
 }
 
+void Program::requestRender() {
+  this->win->Render();
+}
+
 void Program::updateData(int t) {
   // FIXME: think on how to update techniques; do we update all? just active? unsure.
   win->Render();
-  this->techniques[this->activeIdx]->updateData(t);
+  for (Technique *tech : this->techniques) {
+    tech->updateData(t);
+  }
 }
 
-void Program::setActiveTechnique(int idx) {
+void Program::setActiveTechnique(ActiveTechnique tech) {
   // Only change things if a different technique has been selected.
-  if (idx == this->activeIdx) {
+  if (tech == this->activeTech) {
     return;
   }
 
   // check the given idx is valid.
-  if (idx >= this->techniques.size()) {
+  if (tech >= this->techniques.size()) {
     throw std::out_of_range("Index out of range!");
   }
 
-  if (this->activeIdx >= 0 and this->activeIdx < this->techniques.size())
-    this->techniques[this->activeIdx]->unbind(this->win, this->interact);
+  if (this->activeTech >= 0 and this->activeTech < this->techniques.size())
+    this->techniques[this->activeTech]->unbind(this->win, this->interact);
 
-  this->techniques[idx]->bind(this->win, this->interact);
+  this->techniques[tech]->bind(this->win, this->interact);
   
-  this->activeIdx = idx;
+  this->activeTech = tech;
   this->win->Render();
 }
 
diff --git a/particle-track-and-trace/src/Program.h b/particle-track-and-trace/src/Program.h
index 193b76a..fb9932a 100644
--- a/particle-track-and-trace/src/Program.h
+++ b/particle-track-and-trace/src/Program.h
@@ -19,7 +19,7 @@ private:
   /** This attribute models a variable number of vtkRenderers, managed through the abstract Technique class.
     */ 
   std::vector<Technique *> techniques;
-  int activeIdx;
+  ActiveTechnique activeTech;
 
 
   /** The window this program's layers render to.
@@ -72,10 +72,10 @@ public:
     */
   void updateData(int t);
 
+  // TODO: commenting
+  void requestRender();
 
-  // TODO: using an idx to indicate which technique to use is not ideal; use an enum instead? But then the question is where to put it...
-  void setActiveTechnique(int idx);
-
+  void setActiveTechnique(ActiveTechnique tech);
 
   vtkSmartPointer<vtkCamera> getCamera();
 
diff --git a/particle-track-and-trace/src/QT/MainWindow.cpp b/particle-track-and-trace/src/QT/MainWindow.cpp
index 39a0d6a..7595eee 100644
--- a/particle-track-and-trace/src/QT/MainWindow.cpp
+++ b/particle-track-and-trace/src/QT/MainWindow.cpp
@@ -69,7 +69,7 @@ void MainWindow::setupTechniques() {
   program->addTechnique(technique1);
   program->addTechnique(technique2);
 
-  program->setActiveTechnique(0);
+  program->setActiveTechnique(COLGLYPH);
 
   // TODO: implement feature to call this function on widget
   // l->spoofPoints();
@@ -85,6 +85,7 @@ void MainWindow::setupTechniques() {
 void MainWindow::on_FirstButton_clicked(bool checked) {
   if (checked) {
     ui->program->setActiveTechnique(COLGLYPH);
+    ui->program->requestRender();
   }
 }
 
@@ -92,6 +93,7 @@ void MainWindow::on_FirstButton_clicked(bool checked) {
 void MainWindow::on_SecondButton_clicked(bool checked) {
   if (checked) {
     ui->program->setActiveTechnique(GLYPHCOL);
+    ui->program->requestRender();
   }
 }
 
@@ -99,8 +101,9 @@ void MainWindow::on_SecondButton_clicked(bool checked) {
 void MainWindow::on_ComplementaryButton_clicked(bool checked) {
   if (checked) {
     for (Technique *t : ui->program->getTechniques()) {
-      t->setColorMode(COMPLEMENTARY);
+      t->setColourMode(COMPLEMENTARY);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -108,8 +111,9 @@ void MainWindow::on_ComplementaryButton_clicked(bool checked) {
 void MainWindow::on_ContrastingButton_clicked(bool checked) {
   if (checked) {
     for (Technique *t : ui->program->getTechniques()) {
-      t->setColorMode(CONTRASTING);
+      t->setColourMode(CONTRASTING);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -117,8 +121,9 @@ void MainWindow::on_ContrastingButton_clicked(bool checked) {
 void MainWindow::on_MonochromaticButton_clicked(bool checked) {
   if (checked) {
     for (Technique *t : ui->program->getTechniques()) {
-      t->setColorMode(MONOCHROMATIC);
+      t->setColourMode(MONOCHROMATIC);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -128,6 +133,7 @@ void MainWindow::on_SaturateButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setSaturationMode(SATURATED);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -137,6 +143,7 @@ void MainWindow::on_DesaturateButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setSaturationMode(DESATURATED);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -146,6 +153,7 @@ void MainWindow::on_CircleButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setGlyphStyle(CIRCLE);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -155,6 +163,7 @@ void MainWindow::on_TriangleButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setGlyphStyle(TRIANGLE);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -164,6 +173,7 @@ void MainWindow::on_SquareButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setGlyphStyle(SQUARE);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -173,6 +183,7 @@ void MainWindow::on_HexagonButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setGlyphStyle(HEXAGON);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -182,6 +193,7 @@ void MainWindow::on_FullySampledButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setSamplingMode(FULLYSAMPLED);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -191,6 +203,7 @@ void MainWindow::on_RegularlySubsampledButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setSamplingMode(REGULARLYSUBSAMPLED);
     }
+    ui->program->requestRender();
   }
 }
 
@@ -200,6 +213,7 @@ void MainWindow::on_IregularlySubsampledButton_clicked(bool checked) {
     for (Technique *t : ui->program->getTechniques()) {
       t->setSamplingMode(IRREGULARLYSUBSAMPLED);
     }
+    ui->program->requestRender();
   }
 }
 
diff --git a/particle-track-and-trace/src/advection/UVGrid.cpp b/particle-track-and-trace/src/advection/UVGrid.cpp
index 84e9449..f3c2def 100644
--- a/particle-track-and-trace/src/advection/UVGrid.cpp
+++ b/particle-track-and-trace/src/advection/UVGrid.cpp
@@ -31,6 +31,12 @@ UVGrid::UVGrid(string path) {
   for (auto vel: views::zip(us, vs)) {
     uvData.push_back(Vel(vel));
   }
+
+  // FIXME: should really read these from file instead of hard-coding them.
+  this->uMin = -0.381482899188995;
+  this->uMax =  0.566494882106781;
+  this->vMin = -0.381482899188995;
+  this->vMax =  0.470820993185043;
 }
 
 const Vel &UVGrid::operator[](size_t timeIndex, size_t latIndex, size_t lonIndex) const {
diff --git a/particle-track-and-trace/src/advection/UVGrid.h b/particle-track-and-trace/src/advection/UVGrid.h
index 2954d96..6912f94 100644
--- a/particle-track-and-trace/src/advection/UVGrid.h
+++ b/particle-track-and-trace/src/advection/UVGrid.h
@@ -25,6 +25,14 @@ public:
   size_t latSize;
   size_t lonSize;
 
+  /**
+    * Minimum and Maximum values of the u and v variables.
+    */
+  double uMin;
+  double uMax;
+  double vMin;
+  double vMax;
+
   /**
    * Assuming grid is a regular grid, gives the longitudinal spacing of grid.
    * @return longitudinal spacing
diff --git a/particle-track-and-trace/src/commands/SpawnPointCallback.cpp b/particle-track-and-trace/src/commands/SpawnPointCallback.cpp
index f29cb82..aa85257 100644
--- a/particle-track-and-trace/src/commands/SpawnPointCallback.cpp
+++ b/particle-track-and-trace/src/commands/SpawnPointCallback.cpp
@@ -43,6 +43,7 @@ void SpawnPointCallback::Execute(vtkObject *caller, unsigned long evId, void *ca
     points->InsertNextPoint(worldPos[0], worldPos[1], 0);
     this->particlesBeached->InsertNextValue(0);
     this->particlesAge->InsertNextValue(0);
+    this->lutIdx->InsertNextValue(0);
 
     // FIXME:  The below lines cause some weird interaction with our vtkTimer.
     // see github issue  https://github.com/MakeNEnjoy/interactive-track-and-trace/issues/28
@@ -79,3 +80,8 @@ void SpawnPointCallback::setBeached(const vtkSmartPointer<vtkIntArray> &ints) {
 void SpawnPointCallback::setAge(const vtkSmartPointer<vtkIntArray> &ints) {
   this->particlesAge = ints;
 }
+
+
+void SpawnPointCallback::setIdx(const vtkSmartPointer<vtkIntArray> &idx) {
+  this->lutIdx = idx;
+}
diff --git a/particle-track-and-trace/src/commands/SpawnPointCallback.h b/particle-track-and-trace/src/commands/SpawnPointCallback.h
index 083c82d..d33d41e 100644
--- a/particle-track-and-trace/src/commands/SpawnPointCallback.h
+++ b/particle-track-and-trace/src/commands/SpawnPointCallback.h
@@ -24,6 +24,7 @@ public:
   void setBeached(const vtkSmartPointer<vtkIntArray> &parts);
 
   void setAge(const vtkSmartPointer<vtkIntArray> &parts);
+  void setIdx(const vtkSmartPointer<vtkIntArray> &idx);
 
   void setUVGrid(const std::shared_ptr<UVGrid> &uvGrid);
 
@@ -32,6 +33,7 @@ private:
   vtkSmartPointer<vtkRenderer> ren;
   vtkSmartPointer<vtkIntArray> particlesBeached;
   vtkSmartPointer<vtkIntArray> particlesAge;
+  vtkSmartPointer<vtkIntArray> lutIdx;
   std::shared_ptr<UVGrid> uvGrid;
   vtkSmartPointer<vtkAbstractTransform> inverseCartographicProjection;
 
diff --git a/particle-track-and-trace/src/layers/EColLayer.cpp b/particle-track-and-trace/src/layers/EColLayer.cpp
index a7ac2b6..f003d6b 100644
--- a/particle-track-and-trace/src/layers/EColLayer.cpp
+++ b/particle-track-and-trace/src/layers/EColLayer.cpp
@@ -24,6 +24,7 @@
 #include <vtkArrowSource.h>
 
 #include "../CartographicTransformation.h"
+#include "luts.h"
 
 using std::numbers::pi;
 
@@ -38,59 +39,41 @@ EColLayer::EColLayer(std::shared_ptr<UVGrid> uvGrid) {
   this->numLats = uvGrid->latSize;
   this->numLons = uvGrid->lonSize;
 
-  this->strength = vtkSmartPointer<vtkDoubleArray>::New();
-  this->strength->SetName("strength");
-  this->strength->SetNumberOfComponents(1);
-  this->strength->SetNumberOfTuples((numLats-1)*(numLons-1));
-
-  this->direction = vtkSmartPointer<vtkDoubleArray>::New();
-  this->direction->SetName("direction");
-  this->direction->SetNumberOfComponents(1);
-  this->direction->SetNumberOfTuples((numLats-1)*(numLons-1));
+  this->lutIdx = vtkSmartPointer<vtkIntArray>::New();
+  this->lutIdx->SetName("lutIdx");
+  this->lutIdx->SetNumberOfComponents(1);
+  this->lutIdx->SetNumberOfTuples((numLats-1)*(numLons-1));
 
+  calcMaxStrength();
+  buildLuts();
   readCoordinates();
 }
 
-/**
-  * Sets a given rgba colour to a range of values [start, end] in the lut.
-  * @param lut : lookuptable to operate on.
-  * @ param start : starting index of range to assign
-  * @ param end: ending index of range to assign
-  * @param r : red value [0,1]
-  * @param g : green value [0,1]
-  * @param n : blue value [0,1]
-  * @param a : alpha value [0,1]
-  */
-void setLutRange(vtkSmartPointer<vtkLookupTable> lut, int start, int end, double r, double g, double b, double a) {
-  for (int i=start; i <= end; i++) {
-    lut->SetTableValue(i, r, g, b, a);
-  }
+void EColLayer::buildLuts() {
+  this->tables.push_back(buildCyclicComplementary());
+  this->tables.push_back(buildCyclicContrasting());
+  this->tables.push_back(buildCyclicMonochromatic());
+  this->tables.push_back(buildCyclicDesaturated());
+
+  this->activeColourMode = COMPLEMENTARY;
+  this->activeSaturationMode = SATURATED;
 }
 
-// builds a 4-way lookuptable, used to encode the directional component
-vtkSmartPointer<vtkLookupTable> buildLutDirs() {
-  vtkNew<vtkLookupTable> lut;
-  lut->SetNumberOfColors(360);
-  lut->SetTableRange(0, 359);
-  lut->SetScaleToLinear();
-  lut->Build();
-  //currently builds a corkO cyclic colour map, divided into 8 colours (see https://www.fabiocrameri.ch/cycliccolourmaps/)
-  setLutRange(lut, 000, 020, 0.247, 0.243, 0.227, 1);
-  setLutRange(lut, 021, 060, 0.243, 0.267, 0.365, 1);
-  setLutRange(lut, 061, 100, 0.318, 0.416, 0.557, 1);
-  setLutRange(lut, 101, 140, 0.518, 0.620, 0.729, 1);
-  setLutRange(lut, 141, 180, 0.667, 0.757, 0.773, 1);
-  setLutRange(lut, 181, 220, 0.631, 0.769, 0.651, 1);
-  setLutRange(lut, 221, 260, 0.451, 0.639, 0.435, 1);
-  setLutRange(lut, 261, 300, 0.298, 0.431, 0.224, 1);
-  setLutRange(lut, 301, 340, 0.263, 0.310, 0.173, 1);
-  setLutRange(lut, 341, 359, 0.247, 0.243, 0.227, 1);
+void EColLayer::calcMaxStrength() {
+  double u1 = uvGrid->uMin,
+         u2 = uvGrid->uMax,
+         v1 = uvGrid->vMin,
+         v2 = uvGrid->vMax;
 
-  lut->SetNanColor(0,0,0,0);
+  double a = sqrt(u1*u1 + v1*v1);
+  double b = sqrt(u1*u1 + v2*v2);
+  double c = sqrt(u2*u2 + v1*v1);
+  double d = sqrt(u2*u2 + v2*v2);
 
-  return lut;
+  this->maxStrength = max(a, max(b, max(c, d)));
 }
 
+
 // TODO: Bit of a superfunction here; can do with some refactoring.
 void EColLayer::readCoordinates() {
   vtkNew<vtkPoints> points;
@@ -134,35 +117,27 @@ void EColLayer::readCoordinates() {
         }
         u /= 4;
         v /= 4;
-        this->strength->SetTuple1(cellId, std::sqrt(u*u + v*v));
-        this->direction->SetTuple1(cellId++, atan(u/v)*180/pi);
+        this->lutIdx->SetTuple1(cellId++, calcIndex(u,v, this->maxStrength));
       }
       latIndex++;
     }
     lonIndex++;
   }
 
-  data->GetCellData()->AddArray(this->strength);
-  data->GetCellData()->AddArray(this->direction);
-  // data->GetCellData()->SetActiveScalars("strength");
+  data->GetCellData()->AddArray(this->lutIdx);
+  data->GetCellData()->SetActiveScalars("lutIdx");
 
-  vtkNew<vtkPolyDataMapper>(mapper);
-  mapper->SetInputData(data);
-  mapper->SetLookupTable(buildLutDirs());
-  mapper->UseLookupTableScalarRangeOn();
-  mapper->Update();
-  data->GetCellData()->SetActiveScalars("direction");
+  this->mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
+  this->mapper->SetInputData(data);
+  setColourMode(COMPLEMENTARY);
+  this->mapper->UseLookupTableScalarRangeOn();
+  this->mapper->Update();
 
   vtkNew<vtkActor> actor;
-  actor->SetMapper(mapper);
+  actor->SetMapper(this->mapper);
   actor->GetProperty()->SetColor(0, 1, 0);
   actor->GetProperty()->SetOpacity(0.5);
 
-  // vtkNew<vtkActor> act2;
-  // act2->SetMapper(mapper);
-  // act2->GetProperty()->SetRepresentationToWireframe();
-  // ren->AddActor(act2);
-
   this->ren->AddActor(actor);
 }
 
@@ -181,9 +156,50 @@ void EColLayer::updateData(int t)   {
       }
       u /= 4;
       v /= 4;
-      this->strength->SetTuple1(i, std::sqrt(u*u + v*v));
-      this->direction->SetTuple1(i++, atan(u/v)*180/pi);
+      this->lutIdx->SetTuple1(i++, calcIndex(u,v, this->maxStrength));
     }
   }
-  this->strength->Modified();
+  this->lutIdx->Modified();
+}
+
+
+void EColLayer::setColourMode(ColourMode mode) {
+  this->activeColourMode = mode;
+  if (this->activeSaturationMode == DESATURATED) return;
+  
+  this->mapper->SetLookupTable(this->tables[mode]);
+}
+
+void EColLayer::setSaturationMode(SaturationMode mode) {
+  this->activeSaturationMode = mode;
+
+  if (mode == DESATURATED) {
+    this->mapper->SetLookupTable(this->tables[mode]);
+  } else {
+    this->mapper->SetLookupTable(this->tables[this->activeColourMode]);
+  }
+}
+
+
+int calcIndex(double u, double v, double maxStren) {
+  int angleIdx = calcAngleIndex(u,v);
+  int strIdx = calcStrengthIndex(u,v, maxStren);
+
+  return angleIdx+strIdx*10;
+}
+
+int calcAngleIndex(double u, double v) {
+  double angle = (atan2(v,u)+pi) * 180 / pi;
+  return (int)std::floor(angle/360*10) % 10;
+}
+
+// TODO: there's room for improvement in this function.
+// Currently maps all strengths to [0,10) where 10 is assigned when strength >= maxStrength/2
+// But this is completely heuristic - a more accurate calculation could take into account mean/std of velocity strengths, or do something more fancy with the maxStrength value.
+int calcStrengthIndex(double u, double v, double maxStren) {
+  double strength = sqrt(u*u + v*v);
+  int idx = strength/(maxStren/2)*10;
+
+  if (idx > 9) idx = 9;
+  return idx;
 }
diff --git a/particle-track-and-trace/src/layers/EColLayer.h b/particle-track-and-trace/src/layers/EColLayer.h
index 1097d21..ded1b48 100644
--- a/particle-track-and-trace/src/layers/EColLayer.h
+++ b/particle-track-and-trace/src/layers/EColLayer.h
@@ -14,9 +14,13 @@
   */
 class EColLayer : public Layer {
 private:
-  vtkSmartPointer<vtkDoubleArray> strength;
-  vtkSmartPointer<vtkDoubleArray> direction;
+  vtkSmartPointer<vtkIntArray> lutIdx;
+  vtkSmartPointer<vtkPolyDataMapper> mapper;
+  std::vector<vtkSmartPointer<vtkLookupTable>> tables;
+  ColourMode activeColourMode;
+  SaturationMode activeSaturationMode;
   std::shared_ptr<UVGrid> uvGrid;
+  double maxStrength;
   int numLats;
   int numLons;
 
@@ -25,11 +29,13 @@ private:
     */
   void readCoordinates();
 
+  /** This function calculates the maximum strength values for the associated uvGrid
+   */
+  void calcMaxStrength();
 
-  /** This private function builds up the lookup table VTK uses when determning what colour each cell ought to be.
+  /** This function builds the used lookuptables and adds them to the tables attribute.
     */
-  // TODO: implement this function.
-  void buildLut();
+  void buildLuts();
 
 public:
   /** Constructor.
@@ -39,9 +45,37 @@ public:
   /** updates the map to reflect the given timestamp in the dataset.
     * @param t : the time at which to fetch the data.
     */
-  void updateData(int t);
+  void updateData(int t) override;
+
+
+  void setColourMode(ColourMode mode) override;
+  void setSaturationMode(SaturationMode mode) override;
 
 };
 
 
+/** Calculates the discrete index of a given velocity strength, taking into account both strength and direction.
+  * Maps to a 10*10 lookuptable, in which the columns are discrete colours (mapped to direction), and rows are discrete opacities (mapped to strength).
+  * @param u : longitudinal velocity
+  * @param v : latitudinal velocity
+  * @param maxStren : maximum strength value
+  * @return index in a 10*10 lookuptable.
+  */
+int calcIndex(double u, double v, double maxStren);
+
+/** Calculates the discrete index of the angle of a velocity, mapping it to the range [0,10).
+  * @param u : longitudinal velocity
+  * @param v : latitudinal velocity
+  * @return index in the range [0,10)
+  */
+int calcAngleIndex(double u, double v);
+
+/** Calculates the discrete index of the strength of a velocity, mapping it to the range [0,10).
+  * @param u : longitudinal velocity
+  * @param v : latitudinal velocity
+  * @param maxStren : maximum strength value
+  * @return index in the range [0,10) 
+  */
+int calcStrengthIndex(double u, double v, double maxStren);
+
 #endif
diff --git a/particle-track-and-trace/src/layers/LColLayer.cpp b/particle-track-and-trace/src/layers/LColLayer.cpp
index 7aa7f3f..486a590 100644
--- a/particle-track-and-trace/src/layers/LColLayer.cpp
+++ b/particle-track-and-trace/src/layers/LColLayer.cpp
@@ -21,6 +21,9 @@
 
 #include "../CartographicTransformation.h"
 
+// TODO: spawning one particle per event is nice and all, but for a colour map doesnt really look great
+// potential solution: spawn a number of particles randomly around the selected point instead.
+// Would involve a custom callback function probably.
 vtkSmartPointer<SpawnPointCallback> LColLayer::createSpawnPointCallback() {
   vtkNew<SpawnPointCallback> newPointCallBack;
   newPointCallBack->setPoints(this->points);
@@ -28,6 +31,7 @@ vtkSmartPointer<SpawnPointCallback> LColLayer::createSpawnPointCallback() {
   newPointCallBack->setUVGrid(this->uvGrid);
   newPointCallBack->setBeached(this->particlesBeached);
   newPointCallBack->setAge(this->particlesAge);
+  newPointCallBack->setIdx(this->lutIdx);
   return newPointCallBack;
 }
 
@@ -80,6 +84,10 @@ LColLayer::LColLayer(std::shared_ptr<UVGrid> uvGrid, std::unique_ptr<AdvectionKe
   this->particlesAge->SetName("particlesAge");
   this->particlesAge->SetNumberOfComponents(1);
 
+  this->lutIdx = vtkSmartPointer<vtkIntArray>::New();
+  this->lutIdx->SetName("lutIdx");
+  this->lutIdx->SetNumberOfComponents(1);
+
 
   // pipeline 2
   this->data = vtkSmartPointer<vtkPolyData>::New();
diff --git a/particle-track-and-trace/src/layers/LColLayer.h b/particle-track-and-trace/src/layers/LColLayer.h
index 408d91d..8c45113 100644
--- a/particle-track-and-trace/src/layers/LColLayer.h
+++ b/particle-track-and-trace/src/layers/LColLayer.h
@@ -16,6 +16,7 @@ private:
   vtkSmartPointer<vtkPolyData> data;
   vtkSmartPointer<vtkIntArray> particlesBeached;
   vtkSmartPointer<vtkIntArray> particlesAge;
+  vtkSmartPointer<vtkIntArray> lutIdx;
   vtkSmartPointer<vtkIntArray> cellParticleDensity;
   vtkSmartPointer<SpawnPointCallback> callback;
   std::unique_ptr<AdvectionKernel> advector;
diff --git a/particle-track-and-trace/src/layers/LGlyphLayer.cpp b/particle-track-and-trace/src/layers/LGlyphLayer.cpp
index bcc8e89..13a2169 100644
--- a/particle-track-and-trace/src/layers/LGlyphLayer.cpp
+++ b/particle-track-and-trace/src/layers/LGlyphLayer.cpp
@@ -19,6 +19,7 @@
 #include <vtkCamera.h>
 
 #include "../CartographicTransformation.h"
+#include "luts.h"
 
 vtkSmartPointer<SpawnPointCallback> LGlyphLayer::createSpawnPointCallback() {
   vtkNew<SpawnPointCallback> newPointCallBack;
@@ -27,62 +28,13 @@ vtkSmartPointer<SpawnPointCallback> LGlyphLayer::createSpawnPointCallback() {
   newPointCallBack->setUVGrid(this->uvGrid);
   newPointCallBack->setBeached(this->particlesBeached);
   newPointCallBack->setAge(this->particlesAge);
+  newPointCallBack->setIdx(this->lutIdx);
   return newPointCallBack;
 }
 
-// Further notes; current thinking is to allow tracking a particle's age by using a scalar array in the VtkPolyData. This would be incremented for every tick/updateData function call.
-
-/**
- * Build and returns a vtkLookupTable for the given number of colours in grayscale.
- * @param n : number of colours to add to the SetTableRange
- * @return : a vtkLookupTable with grayscale colours from [1,1,1,1] to [0.25, 0.25, 0.25, 1] in n steps.
- */
-vtkSmartPointer<vtkLookupTable> buildLutBrightness(int n) {
-  vtkNew<vtkLookupTable> lut;
-  lut->SetNumberOfColors(n);
-  lut->SetTableRange(0, n);
-  lut->SetScaleToLinear();
-  lut->Build();
-  for (int i=0; i < n; i++) {
-    lut->SetTableValue(i, 1-(0.75*i/(n-1)), 1-(0.75*i/(n-1)), 1-(0.75*i/(n-1)), 1);
-  }
-  lut->UseAboveRangeColorOn();
-  lut->SetAboveRangeColor(0.2, 0.2, 0.2, 1);
-  
-  // We cheat a little here: any particle with an age of -1 is out of bounds, and thus set invisible.
-  lut->UseBelowRangeColorOn();
-  lut->SetBelowRangeColor(1,1,1,0);
-
-  return lut;
-}
-
-/**
- * Build and returns a vtkLookupTable for the given number of colours in grayscale.
- * @param n : number of colours to add to the SetTableRange
- * @return : a vtkLookupTable with grayscale colours from [1,1,1,1] to [1,1,1,0.25] in n steps.
- */
-vtkSmartPointer<vtkLookupTable> buildLutOpacity(int n) {
-  vtkNew<vtkLookupTable> lut;
-  lut->SetNumberOfColors(n);
-  lut->SetTableRange(0, n);
-  lut->SetScaleToLinear();
-  lut->Build();
-  for (int i=0; i < n; i++) {
-    lut->SetTableValue(i, 1, 0, 1, 1-(0.75*i/(n-1)));
-  }
-  lut->UseAboveRangeColorOn();
-  lut->SetAboveRangeColor(1,0,1,0.20);
-  
-  // We cheat a little here: any particle with an age of -1 is out of bounds, and thus set invisible.
-  lut->UseBelowRangeColorOn();
-  lut->SetBelowRangeColor(1,1,1,0);
-
-  return lut;
-}
 
 LGlyphLayer::LGlyphLayer(std::shared_ptr<UVGrid> uvGrid, std::unique_ptr<AdvectionKernel> advectionKernel) {
-  this->luts.push(buildLutOpacity(512));
-  this->luts.push(buildLutBrightness(512));
+  buildLuts();
 
   this->ren = vtkSmartPointer<vtkRenderer>::New();
   this->ren->SetLayer(2);
@@ -92,16 +44,14 @@ LGlyphLayer::LGlyphLayer(std::shared_ptr<UVGrid> uvGrid, std::unique_ptr<Advecti
   data->SetPoints(this->points);
 
   this->particlesBeached = vtkSmartPointer<vtkIntArray>::New();
-  this->particlesBeached->SetName("particlesBeached");
-  this->particlesBeached->SetNumberOfComponents(0);
-
   this->particlesAge = vtkSmartPointer<vtkIntArray>::New();
-  this->particlesAge->SetName("particlesAge");
-  this->particlesAge->SetNumberOfComponents(0);
 
-  data->GetPointData()->AddArray(this->particlesBeached);
-  data->GetPointData()->AddArray(this->particlesAge);
-  data->GetPointData()->SetActiveScalars("particlesAge");
+  this->lutIdx = vtkSmartPointer<vtkIntArray>::New();
+  this->lutIdx->SetName("lutIdx");
+  this->lutIdx->SetNumberOfComponents(0);
+
+  data->GetPointData()->AddArray(this->lutIdx);
+  data->GetPointData()->SetActiveScalars("lutIdx");
 
   advector = std::move(advectionKernel);
   this->uvGrid = uvGrid;
@@ -124,11 +74,7 @@ LGlyphLayer::LGlyphLayer(std::shared_ptr<UVGrid> uvGrid, std::unique_ptr<Advecti
   this->mapper->SetInputConnection(glyph2D->GetOutputPort());
   this->mapper->SetColorModeToMapScalars();
 
-  auto lut = this->luts.front();
-  mapper->SetLookupTable(lut);
-  this->luts.pop();
-  this->luts.push(lut);
-
+  setColourMode(COMPLEMENTARY);
   this->mapper->UseLookupTableScalarRangeOn();
   this->mapper->Update();
   
@@ -140,6 +86,17 @@ LGlyphLayer::LGlyphLayer(std::shared_ptr<UVGrid> uvGrid, std::unique_ptr<Advecti
   this->callback = createSpawnPointCallback();
 }
 
+
+void LGlyphLayer::buildLuts() {
+  this->tables.push_back(buildComplementary());
+  this->tables.push_back(buildComplementary());
+  this->tables.push_back(buildComplementary());
+  this->tables.push_back(buildDesaturated());
+
+  this->activeColourMode = COMPLEMENTARY;
+  this->activeSaturationMode = SATURATED;
+}
+
 void LGlyphLayer::spoofPoints() {
   for (int i=0; i < 330; i+=5) {
     for (int j=0; j < 330; j+=5) {
@@ -162,8 +119,8 @@ void LGlyphLayer::updateData(int t) {
     this->points->GetPoint(n, point);
     if (point[0] <= this->uvGrid->lonMin() or point[0] >= this->uvGrid->lonMax() or point[1] <= this->uvGrid->latMin() or point[1] >= this->uvGrid->latMax()) {
       // sets any particle out of bounds to be beached - so it gets assigned the right colour in the lookup table.
-      this->particlesBeached->SetValue(n, this->beachedAtNumberOfTimes+1);
       this->particlesAge->SetValue(n, -1);
+      this->lutIdx->SetTuple1(n, -1);
       continue;
     }
     
@@ -186,11 +143,15 @@ void LGlyphLayer::updateData(int t) {
       // if the particle's location remains unchanged, increase beachedFor number. Else, decrease it and update point position.
       if (oldX == point[0] and oldY == point[1]) {
         this->particlesBeached->SetValue(n, beachedFor+1);
+        this->lutIdx->SetTuple1(n, beachedFor == this->beachedAtNumberOfTimes-2 ? calcIndex(age+1, true) : calcIndex(age+1, false));
       } else {
         this->particlesBeached->SetValue(n, std::max(beachedFor-1, 0));
         this->points->SetPoint(n, point);
+        this->lutIdx->SetTuple1(n, calcIndex(age+1, false));
         modifiedData = true;
       }
+    } else {
+      this->lutIdx->SetTuple1(n, calcIndex(age+1, true));
     }
   }
   if (modifiedData) {
@@ -199,6 +160,17 @@ void LGlyphLayer::updateData(int t) {
   }
 }
 
+int LGlyphLayer::calcIndex(int age, bool beached) {
+  // particle out of bounds.
+  if (age == -1) return -1;
+
+  int mod = beached ? 50 : 0;
+  int ageCalc = age/60;
+  if (ageCalc >= 50) ageCalc = 49;
+
+  return ageCalc + mod;
+}
+
 void LGlyphLayer::addObservers(vtkSmartPointer<vtkRenderWindowInteractor> interactor) {
   interactor->AddObserver(vtkCommand::LeftButtonPressEvent, this->callback);
   interactor->AddObserver(vtkCommand::LeftButtonReleaseEvent, this->callback);
@@ -212,13 +184,25 @@ void LGlyphLayer::removeObservers(vtkSmartPointer<vtkRenderWindowInteractor> int
 }
 
 
-void LGlyphLayer::cycleGlyphStyle() {
-  auto lut = this->luts.front();
-  this->mapper->SetLookupTable(lut);
-  this->luts.pop();
-  this->luts.push(lut);
+void LGlyphLayer::setColourMode(ColourMode mode) {
+
+  this->activeColourMode = mode;
+  if (this->activeSaturationMode == DESATURATED) return;
+  
+  this->mapper->SetLookupTable(this->tables[mode]);
 }
 
+void LGlyphLayer::setSaturationMode(SaturationMode mode) {
+  this->activeSaturationMode = mode;
+
+  if (mode == DESATURATED) {
+    this->mapper->SetLookupTable(this->tables[mode]);
+  } else {
+    this->mapper->SetLookupTable(this->tables[this->activeColourMode]);
+  }
+}
+
+
 void LGlyphLayer::setDt(int dt) {
   this->dt = dt;
 }
diff --git a/particle-track-and-trace/src/layers/LGlyphLayer.h b/particle-track-and-trace/src/layers/LGlyphLayer.h
index 2c1dc4d..0a1411c 100644
--- a/particle-track-and-trace/src/layers/LGlyphLayer.h
+++ b/particle-track-and-trace/src/layers/LGlyphLayer.h
@@ -4,7 +4,6 @@
 #include "Layer.h"
 #include "../advection/kernel/AdvectionKernel.h"
 #include "../commands/SpawnPointCallback.h"
-#include <queue>
 #include <vtkPolyData.h>
 #include <vtkInteractorStyle.h>
 
@@ -17,14 +16,21 @@ private:
   vtkSmartPointer<vtkPolyData> data;
   vtkSmartPointer<vtkIntArray> particlesBeached;
   vtkSmartPointer<vtkIntArray> particlesAge;
+  vtkSmartPointer<vtkIntArray> lutIdx;
   vtkSmartPointer<vtkPolyDataMapper> mapper;
   std::unique_ptr<AdvectionKernel> advector;
   std::shared_ptr<UVGrid> uvGrid;
   int dt = 3600;
   int beachedAtNumberOfTimes = 20;
-  std::queue<vtkSmartPointer<vtkLookupTable>> luts;
+  std::vector<vtkSmartPointer<vtkLookupTable>> tables;
+  ColourMode activeColourMode;
+  SaturationMode activeSaturationMode;
   vtkSmartPointer<SpawnPointCallback> callback;
 
+
+  void buildLuts();
+  int calcIndex(int age, bool beached);
+
 public:
   /** Constructor.
     */
@@ -46,9 +52,8 @@ public:
   void addObservers(vtkSmartPointer<vtkRenderWindowInteractor> interactor) override;
   void removeObservers(vtkSmartPointer<vtkRenderWindowInteractor> interactor) override;
 
-  /** This function cycles which lut is used for the layer, according to the lookuptables in the luts attribute.
-   */
-  void cycleGlyphStyle();
+  void setColourMode(ColourMode mode) override;
+  void setSaturationMode(SaturationMode mode) override;
 
   /** 
    * Sets a custom DT value, needed for advect calls to the simulation logic.
diff --git a/particle-track-and-trace/src/layers/Layer.cpp b/particle-track-and-trace/src/layers/Layer.cpp
index 500a5a2..d9ef36c 100644
--- a/particle-track-and-trace/src/layers/Layer.cpp
+++ b/particle-track-and-trace/src/layers/Layer.cpp
@@ -14,10 +14,11 @@ void Layer::setCamera(vtkSmartPointer<vtkCamera> cam) {
 }
 
 
+// do nothing by default for these functions.
 void Layer::updateData(int t) {}
 void Layer::addObservers(vtkSmartPointer<vtkRenderWindowInteractor> interactor) {}
 void Layer::removeObservers(vtkSmartPointer<vtkRenderWindowInteractor> interactor) {}
-void Layer::setColorMode(ColourMode mode) {}
+void Layer::setColourMode(ColourMode mode) {}
 void Layer::setSaturationMode(SaturationMode mode) {}
 void Layer::setGlyphStyle(GlyphStyle style) {}
 void Layer::setSamplingMode(SamplingMode mode) {}
diff --git a/particle-track-and-trace/src/layers/Layer.h b/particle-track-and-trace/src/layers/Layer.h
index 3eaf1b0..2b9f96d 100644
--- a/particle-track-and-trace/src/layers/Layer.h
+++ b/particle-track-and-trace/src/layers/Layer.h
@@ -41,7 +41,8 @@ public:
   virtual void setCamera(vtkSmartPointer<vtkCamera> cam);
 
 
-  virtual void setColorMode(ColourMode mode);
+  // TODO: Comments
+  virtual void setColourMode(ColourMode mode);
   virtual void setSaturationMode(SaturationMode mode);
   virtual void setGlyphStyle(GlyphStyle style);
   virtual void setSamplingMode(SamplingMode mode);
diff --git a/particle-track-and-trace/src/layers/Technique.cpp b/particle-track-and-trace/src/layers/Technique.cpp
index c4db355..a877ae9 100644
--- a/particle-track-and-trace/src/layers/Technique.cpp
+++ b/particle-track-and-trace/src/layers/Technique.cpp
@@ -50,9 +50,9 @@ void Technique::unbind(vtkSmartPointer<vtkRenderWindow> win, vtkSmartPointer<vtk
 }
 
 
-void Technique::setColorMode(ColourMode mode) {
+void Technique::setColourMode(ColourMode mode) {
   for (Layer *l : this->layers) {
-    l->setColorMode(mode);
+    l->setColourMode(mode);
   }
 }
 
diff --git a/particle-track-and-trace/src/layers/Technique.h b/particle-track-and-trace/src/layers/Technique.h
index e594221..af8a183 100644
--- a/particle-track-and-trace/src/layers/Technique.h
+++ b/particle-track-and-trace/src/layers/Technique.h
@@ -7,6 +7,7 @@
 #include "enums.h"
 
 class Technique {
+  //TODO: comments
 private:
   std::vector<Layer *> layers;
   vtkSmartPointer<vtkCamera> cam;
@@ -20,7 +21,7 @@ public:
   void bind(vtkSmartPointer<vtkRenderWindow> win, vtkSmartPointer<vtkRenderWindowInteractor> intr); 
   void unbind(vtkSmartPointer<vtkRenderWindow> win, vtkSmartPointer<vtkRenderWindowInteractor> intr);
 
-  void setColorMode(ColourMode mode);
+  void setColourMode(ColourMode mode);
   void setSaturationMode(SaturationMode mode);
   void setGlyphStyle(GlyphStyle style);
   void setSamplingMode(SamplingMode mode);
diff --git a/particle-track-and-trace/src/layers/enums.h b/particle-track-and-trace/src/layers/enums.h
index 537dc58..2639e07 100644
--- a/particle-track-and-trace/src/layers/enums.h
+++ b/particle-track-and-trace/src/layers/enums.h
@@ -2,6 +2,7 @@
 #define ENUMS_H
 
 enum ActiveTechnique {
+  NOTECH = -1,
   COLGLYPH = 0,
   GLYPHCOL = 1,
 };
@@ -16,7 +17,7 @@ enum ColourMode {
 
 enum SaturationMode {
   SATURATED = 0,
-  DESATURATED = 1,
+  DESATURATED = 3,
 };
 
 
diff --git a/particle-track-and-trace/src/layers/luts.cpp b/particle-track-and-trace/src/layers/luts.cpp
new file mode 100644
index 0000000..d7e0e8b
--- /dev/null
+++ b/particle-track-and-trace/src/layers/luts.cpp
@@ -0,0 +1,205 @@
+#include <vtkLookupTable.h>
+#include <vtkColorTransferFunction.h>
+#include "luts.h"
+
+// LGlyph tables
+vtkSmartPointer<vtkLookupTable> buildComplementary() {
+  // uses a modified navia colour map as base.
+  // https://www.fabiocrameri.ch/colourmaps/
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100);
+  lut->SetTableRange(0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  vtkNew<vtkColorTransferFunction> colorTransferFunction;
+  colorTransferFunction->AddRGBPoint(0, 0.317647, 0.52549, 0.329412);
+  colorTransferFunction->AddRGBPoint(49, 0.584, 0.584, 0.584);
+
+  double c[3];
+  int idx=0;
+  for (double notBeached=1; notBeached >= 0.5; notBeached-=0.5) {
+    for (int i=0; i < 50; i++) {
+      colorTransferFunction->GetColor(i, c);
+      lut->SetTableValue(idx++, c[0], c[1], c[2], notBeached);
+    }
+  }
+
+  lut->UseBelowRangeColorOn();
+  lut->SetBelowRangeColor(1,1,1,0);
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildDesaturated() {
+  // uses the grayC colour map.
+  // https://www.fabiocrameri.ch/colourmaps/
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100);
+  lut->SetTableRange(0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  vtkNew<vtkColorTransferFunction> colorTransferFunction;
+  colorTransferFunction->AddRGBPoint(0, 0.313725, 0.313725, 0.313725);
+  colorTransferFunction->AddRGBPoint(49, 0.909804, 0.909804, 0.909804);
+
+  double c[3];
+  int idx=0;
+  for (double notBeached=1; notBeached >= 0.5; notBeached-=0.5) {
+    for (int i=0; i < 50; i++) {
+      colorTransferFunction->GetColor(i, c);
+      lut->SetTableValue(idx++, c[0], c[1], c[2], notBeached);
+    }
+  }
+
+  lut->UseBelowRangeColorOn();
+  lut->SetBelowRangeColor(1,1,1,0);
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+// ECol tables
+vtkSmartPointer<vtkLookupTable> buildCyclicComplementary() {
+  // uses the corkO cyclic colour map
+  // https://www.fabiocrameri.ch/colourmaps/
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100);
+  lut->SetTableRange(0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  int idx=0;
+  for (double opacity=0.1; opacity <= 1.0; opacity+=0.1) {
+    lut->SetTableValue(idx++,  0, 1, 1, opacity);
+    lut->SetTableValue(idx++,  0, 0.9, 0.9, opacity);
+    lut->SetTableValue(idx++,  0, 0.8, 0.8, opacity);
+    lut->SetTableValue(idx++, 0, 0.7, 0.7, opacity);
+    lut->SetTableValue(idx++, 0, 0.6, 0.6, opacity);
+    lut->SetTableValue(idx++, 0, 0.5, 0.5, opacity);
+    lut->SetTableValue(idx++, 0, 0.4, 0.4, opacity);
+    lut->SetTableValue(idx++,  0, 0.3, 0.3, opacity);
+    lut->SetTableValue(idx++,  0, 0.2, 0.2, opacity);
+    lut->SetTableValue(idx++,  0, 0.1, 0.1, opacity);
+  }
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildCyclicContrasting() {
+  // uses the romaO cyclic colour map.
+  // https://www.fabiocrameri.ch/colourmaps/
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100.0);
+  lut->SetTableRange(0.0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  int idx=0.0;
+  for (double opacity=0.1; opacity <= 1.0; opacity+=0.1) {
+    lut->SetTableValue(idx++, 0.45098, 0.223529, 0.341176, opacity);
+    lut->SetTableValue(idx++, 0.529412, 0.25098, 0.215686, opacity);
+    lut->SetTableValue(idx++, 0.639216, 0.403922, 0.172549, opacity);
+    lut->SetTableValue(idx++, 0.764706, 0.639216, 0.294118, opacity);
+    lut->SetTableValue(idx++, 0.839216, 0.847059, 0.576471, opacity);
+    lut->SetTableValue(idx++, 0.705882, 0.870588, 0.776471, opacity);
+    lut->SetTableValue(idx++, 0.454902, 0.733333, 0.803922, opacity);
+    lut->SetTableValue(idx++, 0.309804, 0.533333, 0.72549, opacity);
+    lut->SetTableValue(idx++, 0.360784, 0.32549, 0.545098, opacity);
+    lut->SetTableValue(idx++, 0.447059, 0.223529, 0.34902, opacity);
+  }
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildCyclicMonochromatic() {
+  // uses a slightly modified 9-class blues 
+  // https://colorbrewer2.org/#type=sequential&scheme=Blues&n=9
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100.0);
+  lut->SetTableRange(0.0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  int idx=0.0;
+  for (double opacity=0.1; opacity <= 1.0; opacity+=0.1) {
+    lut->SetTableValue(idx++, 0.258824, 0.572549, 0.776471, opacity);
+    lut->SetTableValue(idx++, 0.129412, 0.443137, 0.709804, opacity);
+    lut->SetTableValue(idx++, 0.031373, 0.317647, 0.611765, opacity);
+    lut->SetTableValue(idx++, 0.031373, 0.188235, 0.419608, opacity);
+    lut->SetTableValue(idx++, 0.968627, 0.984314, 1.0, opacity);
+    lut->SetTableValue(idx++, 0.870588, 0.921569, 0.968627, opacity);
+    lut->SetTableValue(idx++, 0.776471, 0.858824, 0.937255, opacity);
+    lut->SetTableValue(idx++, 0.619608, 0.792157, 0.882353, opacity);
+    lut->SetTableValue(idx++, 0.419608, 0.682353, 0.839216, opacity);
+    lut->SetTableValue(idx++, 0.180392, 0.494118, 0.698039, opacity);
+  }
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildCyclicDesaturated() {
+  // uses a modified brocO colour map
+  // https://www.fabiocrameri.ch/colourmaps/
+  vtkNew<vtkLookupTable> lut;
+  lut->SetNumberOfColors(100.0);
+  lut->SetTableRange(0.0, 99);
+  lut->SetScaleToLinear();
+  lut->Build();
+
+  int idx=0.0;
+  for (double opacity=0.1; opacity <= 1.0; opacity+=0.1) {
+    lut->SetTableValue(idx++, 44, 44, 44, opacity);
+    lut->SetTableValue(idx++, 56, 56, 56, opacity);
+    lut->SetTableValue(idx++, 85, 85, 85, opacity);
+    lut->SetTableValue(idx++, 114, 114, 114, opacity);
+    lut->SetTableValue(idx++, 149, 149, 149, opacity);
+    lut->SetTableValue(idx++, 146, 146, 146, opacity);
+    lut->SetTableValue(idx++, 110, 110, 110, opacity);
+    lut->SetTableValue(idx++, 78, 78, 78, opacity);
+    lut->SetTableValue(idx++, 52, 52, 52, opacity);
+    lut->SetTableValue(idx++, 45, 45, 45, opacity);
+  }
+
+  lut->SetNanColor(0.0,0,0,0);
+  return lut;  
+}
+
+
+// LCol tables
+vtkSmartPointer<vtkLookupTable> buildDensityComplementary() {
+  vtkNew<vtkLookupTable> lut;
+
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildDensityContrasting() {
+  vtkNew<vtkLookupTable> lut;
+
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildDensityMonochromatic() {
+  vtkNew<vtkLookupTable> lut;
+
+  return lut;  
+}
+
+
+vtkSmartPointer<vtkLookupTable> buildDensityDesaturated() {
+  vtkNew<vtkLookupTable> lut;
+
+  return lut;  
+}
diff --git a/particle-track-and-trace/src/layers/luts.h b/particle-track-and-trace/src/layers/luts.h
new file mode 100644
index 0000000..c256737
--- /dev/null
+++ b/particle-track-and-trace/src/layers/luts.h
@@ -0,0 +1,20 @@
+#ifndef LUTS_H
+#define LUTS_H
+#include <vtkLookupTable.h>
+
+// LGlyph tables
+vtkSmartPointer<vtkLookupTable> buildComplementary(); 
+vtkSmartPointer<vtkLookupTable> buildDesaturated(); 
+
+// ECol tables
+vtkSmartPointer<vtkLookupTable> buildCyclicComplementary(); 
+vtkSmartPointer<vtkLookupTable> buildCyclicContrasting(); 
+vtkSmartPointer<vtkLookupTable> buildCyclicMonochromatic(); 
+vtkSmartPointer<vtkLookupTable> buildCyclicDesaturated(); 
+
+// LCol tables
+vtkSmartPointer<vtkLookupTable> buildDensityComplementary(); 
+vtkSmartPointer<vtkLookupTable> buildDensityContrasting(); 
+vtkSmartPointer<vtkLookupTable> buildDensityMonochromatic(); 
+vtkSmartPointer<vtkLookupTable> buildDensityDesaturated(); 
+#endif