Hillshade acetate (on top of 2-component vector fields)
- Implement 2-component vector fields (similar to 1-component scalar fields)
- Optionally, implement 3- and 4- component vector fields (3D and 4D vector fields)
- Implement a hillshader (similar to a heatmap in that it converts values to RGBA colour, but taking into account the two components of the vector field)
- Take an azimuth angle, a light colour and a shade colour.
- Possibly some other colouring algorithm
- Optionally, create a slope acetate to convert a scalar field (elevation) into a vector field (slope vector)