Parametric and Nonparametric Relations in Offset Entities
The two entities of an offset sketch maintain a parametric relation or a nonparametric relation.
Nonparametric Relation
When you offset sketch geometry within an active sketch group or in the top-level sketch, the resultant sketch geometry is created with an offset dimension, but without an offset constraint. The resultant sketch geometry and the original sketch geometry maintain a nonparametric relation. As there is no offset constraint between the original and the offset geometry, you can independently modify both these geometries.
Parametric Relation
When you offset a sketch geometry that belongs to a sketch subgroup within an active sketch group or top-level sketch, the resultant sketch geometry is created with an offset dimension and an offset constraint with respect to the original sketch geometry. The resultant sketch geometry maintains a parametric relation with the original sketch geometry, and is fully defined by the offset dimension and offset constraint. Similarly, if you offset an external geometry, the resultant sketch geometry maintains a parametric relation with the original geometry.
You can break the parametric relation between the original geometry and the offset sketch geometry by deleting the offset dimension. When you delete the offset dimension, the offset constraint is automatically deleted, making the offset sketch geometry independent of the original geometry.
If the resultant sketch maintains a parametric relation with the original sketch, the resultant sketch is updated accordingly in the following cases:
• When you modify the original sketch by removing and adding entities.
• When you replace an entity within the original sketch.