Current location:

Simplify

Applicability:

Cadcorp SIS Map Modeller
Cadcorp SIS Map Editor
Cadcorp SIS ActiveX Modeller

Ribbon Group:

Edit-Clean/Simplify

Conditions for use:

Item Class: All item classes
Minimum number selected: 1
Minimum item status: Editable

Description:

Simplify simplifies the geometry of the selected items.

Note: Using this command before exporting data which is to be used in other software programs will increase the chance of the data being read correctly by the other system.

The OpenGIS Simple Features Specification describes the rules for simple geometry, here is a summary:

A Point item is always simple.
A LineString item is simple if it does not cross itself, and it does not touch itself, except possibly at its end-points.
A Polygon item is simple if its loops do not cross, and its interior is a single connected region. So a doughnut is simple, but a Polygon with disconnected islands is not.

The rules for MultiLineString, items are as follows:

All the components of the multi-item must be simple.
The interiors of each component must not intersect any of the other components.
In a simple MultiLineString, every junction between component lines must have at least three paths leading out of it.
All the Polygons of a simple MultiPolygon must only touch at points.

When you simplify an item, SIS modifies its geometry to follow all of the above rules, changing it as little as possible.

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