SPL Rendering (Settings)

SPL Rendering Settings.
Colour Map

There are three choices of colour map provided:

  • Inferno - a perceptually uniform colour map with monotonically increasing luminance, suitable for the visualisation of scientific data. This is the default colour map for System Optimiser.

  • Rainbow – a traditional colour map seen in many other visualisation applications. Note that rainbow is widely accepted within the scientific community as a technically flawed colour map, due to its lack of perceptual ordering. It can obscure data through its uncontrolled luminance variation, which actively misleads interpretation through the introduction of non-data-dependent gradients. It has been included nonetheless, should you wish to compare output from System Optimiser with other applications that use the Rainbow scale. The Rainbow scale may prove useful in certain scenarios however, such as for comparing directivity measurements.

  • Cividis – a colour map engineered to provide a near identical representation of data for both people with and without forms of colour vision deficiency.

Manual Scale

With manual scale enabled, the maximum and minimum limits of the colour scale can be defined. When the manual scale button is pressed, the automatic scale button is released.

Automatic Scale

With automatic scale enabled, the two parameters presented are ‘headroom’ and ‘range’:

  • The maximum limit of the scale is locked to the highest value of pressure detected within the mapping, plus the headroom value. It is therefore possible to stretch the dataset, or clamp down on it.

  • The minimum limit of the scale is locked to the maximum limit determined by the method above, with the range subtracted.

Automatic scaling is useful for when switching frequently between different frequency ranges of mapping, as there are naturally different ranges of pressure for different frequency ranges. When the automatic scale button is pressed, the manual scale button is released.

Stepped Scale

The pressure mapping within the 3D View can be discretised using the stepped scale option. This has the effect of creating bands of colour within the mapping, useful for qualifying which areas of the audience fall within which band. There are two strategies for determining the stepped scale banding:

  • dB per Step – this quantises the scale into blocks of [dB per Step] level.

  • Number of Steps – this quantises the scale into blocks of [Number of Steps] steps.

The stepped scale option can be enabled for both manual and automatic scales.