Processor Guide

Use this guide to choose the right processor for your use case.

Summary table

Processor Best for Speed Geometry scope Notes
AlignerGeometryProcessor (default) General use Medium Auto-selects by context Recommended default entrypoint
DieussaertGeometryProcessor Polygon-to-polygon alignment Fast Polygon/MultiPolygon focused Usually best first choice for parcel-like workflows
NetworkGeometryProcessor Generic point/line/polygon network behavior Slower Broadest support Use when network-like behavior is required; supports OD strategy behavior for polygon-reference coverage
DirectedNetworkGeometryProcessor Network behavior with one-way constraints Slower Broadest support Forces directed routing (network_use_directed_graph=True); no synthetic component fallback in directed no-path cases
AnchorGeometryProcessor Line workflows where route should follow thematic anchor points Slower Point/Line (+ polygon via delegation) Anchor-guided routing: start/end + angle anchors + periodic anchors; supports directed/one-way parameters; can route over full reference lines after local anchor match
DirectedAnchorGeometryProcessor Anchor-guided lines with one-way constraints Slower Point/Line (+ polygon via delegation) Thin wrapper over Anchor processor with directed mode forced
TopologyProcessor Shared-boundary consistency between neighboring features Slower Topology-aware arc workflow Experimental and specialized
SnapGeometryProcessor Direct vertex/edge snapping behavior Case-dependent Depends on snap strategy Good for explicit snap-driven workflows; OD strategy effects are relevant with polygon-reference coverage

Practical recommendation

  1. Start with AlignerGeometryProcessor (default).
  2. If your scenario is polygon-to-polygon and speed matters, prefer DieussaertGeometryProcessor.
  3. Switch to NetworkGeometryProcessor when mixed geometry types or network behavior are required.
  4. Use AnchorGeometryProcessor when you need anchor-driven line routing (preserving thematic turning structure).
  5. Use DirectedNetworkGeometryProcessor or DirectedAnchorGeometryProcessor when one-way/directionality is a hard requirement.
  6. Use TopologyProcessor only when preserving shared topology across thematic features is a strict requirement.

Directed routing behavior

Directed processors follow one-way metadata from reference features using:

  • network_oneway_field
  • network_oneway_forward_values
  • network_oneway_reverse_values

Practical semantics:

  • If no valid directed path exists, processors keep safe fallback behavior and do not invent artificial reverse paths to bypass direction constraints.
  • Connector edge behavior in directed mode is controlled by:
    • network_allow_connector_edges_when_directed
    • network_directed_connector_penalty_factor

Note on Descriptor

Besides processor selection, Aligner also has a descriptor strategy. The default AlignerDescriptor builds the observations and metadata output fields for each ProcessResult. This is independent from processor selection and can be replaced separately.