Spectrums in Expert Mode
Once you've taken control over Predict Unity, you can enable the Expert Mode to have an even more precise control over the definition of the elements in your scenes.
The Expert Mode can be enabled in the Interface section of the PredictSuite preferences.
Interpolation and extrapolation methods
Some spectrums require an interpolation and/or extrapolation method. These methods define how the spectrum is computed when a value is required between measured wavelengths or outside the measured range.
The interpolation method defines how the values are computed between the values given in the measure file. The method can be :
Linear (default) : the value is a linear interpolation between the two closest values,
Nearest : the value is equal to the closest value.
The extrapolation method defines how the values are computed outside the range of values given in the measure file. The method can be :
Nearest (default) : the value is equal to the closest value,
Zero : the value is 0.
Visualization of a measured spectrum defined with values between 450nm and 650nm, computed with :
Top : interpolation method = Linear (default) and extrapolation method = Nearest (default),
Bottom : interpolation method = Nearest and extrapolation method = Zero.
If the Expert Mode is enabled, you can define these methods for each spectrum. The "Interpolation Method" and "Extrapolation Method" fields are displayed on the concerned spectrums.
Raw spectrums control points
When the Expert Mode is enabled, raw spectrum control points can be edited manually in the type-dependant settings section.
Raw spectrums sampling
When the Expert Mode is enabled, raw spectrums with a degree superior to 2 (Bezier definition of shape Cubic or Quadratic, NURBS definition with degree superior to 2) have an additional setting called "Sampling". Procedural curves such as Bezier or NURBS curves must be sampled in our engine, the sampling defines the granularity of the curve used in the engine : the smaller the sampling, the more points will be used to define the curve.
Raw spectrums using NURBS definition
When the Expert Mode is enabled, raw spectrums can be defined using either a Bezier or a NURBS definition.
NURBS are a generalization of Bezier curves in which the degree defines the number of nearby control points that influence any given point on the curve. In addition, each control point has a weight that controls its impact on the curve : a point with a weight of 0 will have no impact on the curve. The weight of a control point can be edited inside the curve view by right click and dragging on a control point.
