An anchor links an AEC object to another object or to a layout curve or grid. You can create anchors between objects and also remove anchors from objects. AEC objects can be anchored to each other, to AutoCAD objects like lines and circles, or to layout curves or grids.
Automatic and user-defined anchors enable you to use anchors for many different purposes.
Automatic anchors are set by the program. Certain objects are by default anchored to other objects. For example, doors and windows are usually anchored to walls. Curtain wall units or window assemblies might be anchored to curtain walls. Although these anchors are inserted automatically, when you place the objects their behavior can differ slightly. For example, a door that is anchored to a wall can be moved to an unconnected wall. The door cannot, however, be moved outside a wall and stand alone. To do this, you must remove the anchor between door and wall. The anchor of a column to a column grid behaves differently: you can move the column inside the grid, but you cannot move the column to another grid without first removing the anchor.
User-defined anchors are manual links that you can create between two objects. Most anchors are used with layout curves, layout grids, or volumes. You can also attach anchors to other AEC objects or AutoCAD objects.
Anchoring objects to a layout curve can be useful for positioning washbasins along a wall or rafters along a roof. Anchoring objects to layout grids can help you to position columns on a column grid, planters on a sidewalk grid, or tile accents on a floor tile grid.
There are six different types of anchors that you can use to attach objects:
| If you want to… | Then… |
|---|---|
| attach AEC objects to other AEC objects | use object anchors. |
| attach AEC objects to the base curve of other objects, such as lines, arcs, circles, mass elements, polylines, roofs, or walls | use curve anchors. |
| attach objects to nodes on layout curves or grids with leaders | use leader anchors. |
| attach objects to nodes on layout curves or grids | use node anchors. |
| attach objects to cell positions on 2D layout grids and 3D volume grids | use cell anchors. |
| attach objects to volumes on 3D grids | use volume anchors. |