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Albion GIS / CAD Interaction

A great deal of the flexibility and ease of use of the Albion CAD/GIS combination lies in the fluid interaction between CAD and GIS environments. What essentially happens is that the GIS objects are rendered into CAD layers, and these can be manipulated alongside regular CAD objects. Possessing a grasp of how this mechanism works can help you understand certain limitation that you may find during geometric data manipulation.

CAD Layers and GIS Layers

Every GIS layer is rendered to one primary CAD layer, and optionally to a secondary labelling CAD layer. Thus, at most two CAD layers will ever represent one GIS layer. The CAD layers associated with GIS objects have certain restrictions. You may not rename them, and certain operations are not allowed on them. If need be, you may completely dissociate a CAD layer from its GIS roots. Keep in mind that one project is associated with one drawing. This is dealt with more extensively in the Projects topic.

Limitations

When you perform graphical operations on GIS objects, the CAD mechanism facilitates the interaction, and then passes the result on to the GIS. This mode of operation can sometimes enforce limitations on what you can do in a single command.

Sometimes you may receive the error 'This command can only be executed on a single GIS layer'. This means that you may not execute this operation when GIS objects from more than one layer are selected. It should be noted that many of these limitations are artificial and conservative, so if you believe that lifting a restriction of this nature would improve the program's quality, then drop us a line.