| Type | Readable | Writeable | Constant |
| float | Never | In the final section of coloring algorithms | No |
Coloring algorithms use this predefined symbol to return a color index. The range 0..1 for the index value corresponds to the entire gradient when all controls in the Inside or Outside tab of the Layer Properties tool window are set to their default values (Density = 1, Transfer = Linear, Offset = 0). If Repeat Gradient is set to true, the gradient "wraps around", so the index value 1.1 actually corresponds to 0.1.
Before executing the coloring algorithm, the index value is set to 0, so that is the value that will be used if the coloring algorithm doesn't change it.
Example:
#index = 0.5
See #z for an example on the usage of #index.
See Also
#solid (predefined symbol)
#color (predefined symbol)
Writing coloring algorithms