1D transfer function (Colour map)

Fig. 16 1D transfer function (colour map) actor.

Description

The 1D transfer function actor provides a colour map that is (a) displayed in a scene, and that (b) can be used in other actors to map a data value to a colour.

• Data scalar range can be adjusted, as well as number of colour steps, labels, tick marks and position of the colour map in the visualization.

• The actor provides a number of predefined colour maps, as well as Hue-Chroma-Luminance (HCL) colour maps. For the latter, specification of HCL colour maps follows the website of Reto Stauffer.

Adjusting the value range

• Open Transfer function scalar to colour (colour map) → actor properties → range

• Set the minimum and maximum value according to the needs

Changing the colour map type

• Open Transfer function scalar to colour (colour map) → actor properties

• Choose a colourmap type (options: “HLC”, “Editor”, “predefined”, “HSV”). We recommend to choose a HCL colourmap.

  1. HCL: Choose the type of the HCL color map (options: “diverging”, “qualitative”, “sequential single hue”, “sequential multiple hue”). We recommend to use a tool like hclwizard to create a colourmap.

  2. Editor: an integrated colourmap editor opens to create own colourmaps.

  3. Predefined: Choose from predefined colourmaps.

  4. HSV: Load a transfer function from Vapor XLM file.

Adjusting the position

• Open Transfer function scalar to colour (colour map) → actor properties → position

  • Change the X coordinate from -1 (left) to 1 (right)

  • Change the Y coordinate from -1 (bottom) to 1 (top)

  • Adjust the Width and Height of the colourbar displayed in the scene