Model-Based Definition > Model-Based Definition > Creating Various Annotation Types > Dimension Properties > Reference Dimensions > About Reference Dimensions
About Reference Dimensions
Reference dimensions appear on models or in drawings for information only. Therefore, they are read-only and cannot be used to modify the model; however, they are automatically updated during regeneration if changes are made to the model. You can include reference dimension created between edges in Annotation features.
You can use reference dimensions in place of some relations. For example, instead of defining a side of a triangle with the relation
DIAGONAL = SQRT ((D3/2)^2 + D1^2)
- you can use
Reference dimensions can be created in Part, Assembly, and Sketcher modes. They can also be created in Drawing mode, but only if you have a Detailed Drawings license.
Reference dimensions are distinguished from standard dimensions in either of the following ways:
They are followed by the notation REF
To have them appear in parentheses as the default, set the configuration file option parenthesize_ref_dim to yes.
The parameter symbol for reference dimensions is rd# (or rsd# in the case of Sketcher).