A Feature-Based Transformer is one which processes one feature at a time, in isolation from all other features.
Some examples of Feature-Based transformers are:
- AreaCalculator and LengthCalculator: These transformers perform calculations on only one feature at a time. The result of measuring one feature has no impact on the measurement of another.
- CenterPointReplacer: – Each “center of gravity” (geographic center) calculation is unique and independent of other features.
- 3DForcer: Each feature is given Z values to its vertices, but one at a time and without affecting the Z values of other features.
- Feature-Based Transformers don’t always need to process each feature in the same way. The use of attributes for parameter values means the process can vary with the attribute - for example, using an attribute value in the 3DForcer elevation parameter.
- Aggregates: Each aggregate is considered a single feature; for example the measurement of the area of a multi-polygon feature returns a single value, not the value of each component of the aggregate.