Attachment and Associativity

Before adding detailing to your designs, it will be important to understand the following regarding detail attachment and associativity:

• An associative dimension is one that has sufficient geometric information to derive the value it displays. Dimensions are fully associative in both Layout and Model Modes. The stringency of dimension associativity is defined through the Dimensions tab of the Tools>Options dialog. Note that if the displayed value of a dimension is edited, the dimension effectively becomes non-associative.

• Text positions and arrowhead locations are associative.

• By definition, a Detail Symbol is non-associative.

• You can choose to have a dimension revert to its true value by using the Settings dialog sequence (see Detail Options).

Dimension Attachment:

Attachment is determined by the integrity of a dimension’s connection to an entity. A dimension based off of, or positioned from, geometric positions on an entity is an attached dimension. For instance, a dimension attached to two endpoints of a line is an attached dimension. A dimension whose positions are cursor selected, or placed using key-in, is un-attached.

Dimension Associativity:

A dimension is non-associative if the program cannot determine its value, or if any entity required to determine its value is deleted. For instance, a dimension whose value is accurate and updates in accordance to changes made to the entity to which it is attached is considered an "associative" dimension. As a result, dimensions’ whose values have been manually applied or modified are not associative.

NOTE: All non-associative dimensions are also un-attached.  

Tools>Options>Dimensions:

The associativity and attachment status of dimensions is driven by the settings located in the Dimensions tab of the Set Configuration Options dialog, accessible from the Tools>Options pull-down menu. Because you can enable/disable these settings, the integrity of dimension associativity will require a fair amount of discipline on your part. Making dimensions attached to their referenced geometry will allow both dimensions and detail entities to move automatically with the modified geometry upon which they are based. This will make for quicker and more efficient design and revision of files containing dimensioned geometry.

NOTE: None of the settings contained in the Tools>Options>Dimensions dialog will be selectable when a file is loaded (including New File).