Understanding The ActiveX Object Model Introduction

AutoCAD Land Desktop ActiveX & VBA

Understanding The ActiveX Object Model Introduction


The ActiveX Object Model for AutoCAD Land Desktop exposes features and provides access to project data through an object hierarchy. This hierarchy provides a convenient and consistent programming interface to your projects.

The object hierarchy can be grouped into the following categories:


Plan alignments can be defined from tangent, curve, and spiral objects. You can also manage Station Equations.

Project Management

This includes extensions to the AutoCAD object model so that you can manage Land Desktop Projects. It also provides access to Preferences and Project Prototypes.

COM Wrappers for ARX Objects

These are provided for the Point, Contour, and CurveText ARX objects that reside in your drawings. You can modify existing objects, or add and delete objects from the drawing. In addition, programmatic access to the ContourStyle dictionary object is provided so that you can manage the appearance of Contour objects.

Coordinate Geometry

These objects allow you to manage your Cogo Point database, Point Groups, and Description Keys.


Terrain management is exposed through a collection of surfaces that have inputs and generated outputs. You can define a surface from Point Files, Point Groups, Boundaries, Breaklines, Contour data, or DEM Files. You can build a surface and a watershed model. The generated Tin Points, Edges, Faces and Elevation Contours are provided as outputs.


Parcel objects can be defined from line and curve objects. Properties such as area, perimeter, centroid, and name can also be accessed.

Profiles, Cross Sections, and Superelevations

The ActiveX Object model provides access to profiles, cross sections, and superelevations. You can also access the profiles and cross section blocks in the drawing for custom drafting.

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