Convex hull

A convex hull step replaces each feature's geometry with its smallest enclosing convex shape (ST_ConvexHull). Attributes are kept; row count is unchanged.

This is per feature, not one hull for the whole layer. For a single combined outline of every feature, use Dissolve (attributes dropped) or Group by with empty keys when you also need aggregates.

Inputs

• Source layer. Any geometry type. Null geometries are skipped. The step has no parameters in the derived-layer builder.

Output

One row per non-null input geometry:

• Geometry: convex hull of that feature (point / line / polygon depending on the input).
• Properties: copied from the source row.

How to use it on its own

From Analyze (guided)

1. Open a data layer and switch to the Analyze tab.
2. Click Convex hulls for this layer.
3. Optionally edit the title.
4. Click Create derived layer.

The portal creates a private derived layer and opens it. Expect a short server job, not an instant browser result.

From the new-item wizard

1. New-item wizard → Derived layer.
2. Pick a Source.
3. Add a Convex hull step.
4. Save.

Examples

• Fill concave parcels. Source: parcel polygons with bays. Output: each parcel as its convex outline for a simpler selection target.
• Point cloud per-cluster hulls. After you already have one multipoint (or multipolygon) feature per cluster, convex hull turns each into a polygon footprint. Building those clusters is a separate step.

Notes

• Per-feature only in v1. There is no "hull of all input features" switch on this generator.
• Points and short lines. A single point stays a point; two points become a line; three or more become a polygon.
• Multipart inputs produce one hull of the combined parts.