Video: Understanding Constraints
Constraints are non-view specific elements that can function independently of dimensions. Constraint elements appear as blue dashed lines in all views in which their references are visible; dimensions are view-specific. You can modify and delete constraints independently of dimensions or remove them when you delete dimensions.
In Revit, elements can reference each other in many ways, including the following:
- Explicit constraints (such as locked alignments and dimensions) guarantee that the defined relationships will be maintained. Conflicts cause errors and must be resolved.
- Looser constraints (such as dimensions and alignments that are not locked) are often maintained unless a conflict occurs, in which case these constraints may be removed without notice.
- Implied constraints (such as a wall attached to a roof, or 2 walls joined at a corner) are also maintained unless a conflict occurs.
These explicit and implied constraints require that each element knows about the other. That is, one element must reference the other element.
Constraints and Worksets
Constraints belong to the worksets of the elements they constrain. In order to add a constraint, the worksets of all the elements that can be moved by the constraint must be editable.