Scan Geometry Errors

The Scan Geometry Errors algorithm scans an input vector polygon layer for specific geometry and topology defects and outputs a Point vector sink layer representing exact error locations and audit metadata.

Access

• Processing Toolbox: GMD Pipeline → GMD Toolkits → Scan Geometry Errors
• Algorithm ID: gmd_pipeline:scangeometryerrors

When to Use

Use this algorithm when:

• Auditing polygon layers for topological errors prior to boundary management or processing.
• Generating a standalone spatial Error Layer (Point geometry) for styling, visual inspection, or GIS report generation.
• Performing automated batch validation of polygon layers across project folders or scripts.

Parameters

Parameter	Type	Description
Input Polygon Layer	Vector (Polygon)	Target vector polygon layer to scan.
Check Null Geometries	Boolean	Detect features with null geometry objects (True/False).
Check Empty Geometries	Boolean	Detect features with empty geometry shapes (True/False).
Check Invalid Geometries (GEOS)	Boolean	Detect features failing GEOS validity tests (True/False).
Check Self Intersections	Boolean	Detect features with self-intersecting polygon boundaries (True/False).
Check Wrong Geometry Types	Boolean	Detect non-polygon geometries in the layer (True/False).
Check Duplicate Geometries	Boolean	Detect features sharing exact duplicate geometries (True/False).
Error Locations (Point Layer)	Vector Sink (Point)	Output point layer containing precise error locations and metadata.

Output Error Layer Schema

The resulting Error Locations point layer includes the following fields:

Field Name	Type	Description
source_fid	Integer	Feature ID of the source feature containing the error.
layer_name	String	Name of the source layer scanned.
error_type	String	Type of error (e.g. Invalid Geometry, Null Geometry, Self Intersection).
description	String	Detailed explanation of the detected issue.
is_autofixable	Boolean	Indicates whether the issue can be automatically resolved by the Repair algorithm.

Next Steps

Use the generated Error Locations layer to inspect issues visually in QGIS or pass the target layer to the Repair Polygon Geometries processing tool to fix selected error features.