Update README.md

README.md

@@ -27,6 +27,12 @@ A volume renderer, made in Unity3D. See slides from presentation here: https://s
 
 See "DatasetImporterEditorWIndow.cs" for an example.
 
+# How to change the visualisation
+- **Changing rendering mode**: Select the object, find "Volume Rendered Object" in the inspector and expand the "Render mode" dropdown.
+- **Modifying transfer functions**: Click "Volume Rendering" in the menu bar and select "1D Transfer Function" or "2D Transfer Function"
+  - **1D Transfer Function**: X-axis represents density and Y-axis represents alpha (opaccity). Move the grey alpha knots to create a curve for opacity by density. Right-click to add new alpha knots. The bottom gradient-coloured panel maps colour to density. Right-click to add new knots and click on an existing colour knot to modify its colour.
+  - **2D Transfer Function**: X-axis represents density and Y-axis represents gradient magnitude. Click "add rectangle" to add a new rectangle-shape. Move the four sliders (bottom left) to modify size/position. Modify the two sliders to the right to change min/max alpha/opacity. Each rectangle can have one colour (see colour picker).
+
 # Note:
 THe _RawDatasetImporter_ imports raw datasets, where the data is stored sequentially. Some raw datasets contain a header where you can read information about how the data is stored (content format, dimension, etc.), while some datasets expect you to know the layout and format.
 The importer takes the following parameters:
@@ -39,6 +45,7 @@ The importer takes the following parameters:
 
 # Todo:
 - DICOM support
+- Improve 2D Transfer Function editor: Better GUI, more shapes (triangles)
 - Optimise histogram generation
 - Support very large datasets (currently we naively try to create 3D textures with the same dimension as the data)