Frequent tipster Danny Korem explains how to to lock your geometric data with constraints to preserve relationships in your AutoCAD design.

"Engineering disciplines differ from one another in the creation of two kinds of data: clone and univalent-spatial. In the world of manufacturing, each part and assembly designed is definitely clone data, as it is designed to be manufactured in thousands of copies. In the world of AEC and GIS (geospatial information solutions), each parcel and lot is univalent, because it’s located and 'anchored' to univalent coordinates. Buildings, neighborhoods, and cities are all anchored to this globe. In geospatial applications it's obvious that once a map is imported into a scene, it's impossible to move it to another location, exactly as in the real world.

"We architects lack the privilege of anchoring while creating data in CAD environments, but lately we have received some tools that give us a similar ability to anchor our data. You can combine the fix parametric constraint with the Infer Constraints setting to create anchored data. For example, the line (which could represent a map, a surveyor’s map etc.) has an endpoint coincident with a point that has been constrained by the fix parametric constraint. As a result, one cannot move the geometry (both the line and the point) unless the constraints are deleted intentionally.

"In the same way, one can lock building cores to column grids, attached xrefs to specific insertion points, and so forth."



Notes from Cadalyst Tip Reviewer Brian Benton: AutoCAD has parametric constraints — tools that can fix your data in place, and therefore ensure that you retain your linework’s geometric relationships properly. You can add constraints manually, or you can add them with the Infer Constraints setting as you draw.