Variable Driven Modeling and Constraints

When adding a constraint to a feature, you can bind the dimensional value to a variable. When variables are used in this way, you can "redesign" the element simply by changing the active values of the model's variables. This results in the element being regenerated with the new values applied to the constraints for the features. Similar effects can be achieved by binding the value of an element property to a variable. To constrain to the assigned variable value, you can select the available variables from the drop-down menu that appears in the value field while applying the constraint.

While creating a parametric element or adding a feature to an element, you can derive the values of the different dimensional settings from available variables. You can use the button corresponding to the field in the tool setting window to assign a variable or create a new variable to assign. You can also create a new expression to assign to the value. button indicates that a variable is already assigned to the value.

Variables and Parametric Cells

While placing a model as a parametric cell, you can choose which variables and variations to use to define the cell. To enable the placement of a model as a parametric cell, you must set the model’s Can be placed as Cell property to True and its Cell Type to Parametric, in the model's Properties dialog.

Note: A model which has variables or variations but does not meet these requirements cannot be placed as a parametric cell. A model which meets these requirements, can be placed as a parametric cell regardless of whether or not it defines variables or variations. But useful parametric cells usually define either or both.

The variables of a placed parametric cell can be fixed (not editable) or free (editable) depending on the Scope setting set in the Variables dialog. Also, the visibility of the variables of a model placed as a cell, can be controlled with the Display setting in the Variables dialog. Typically, intermediate variables which are used to generate geometry but are not considered useful outward properties of the object being modeled should be set as Hidden.

Set Scope to Instance, if you want the variable editable after placing the cell | Set Scope to Definition if you want the variable to be fixed.

Remapping Variables and Variations - If you try to delete a variable that is assigned to an element, the Confirm Delete alert opens. You can choose to remap the reference to another available variable or confirm to delete:

If (None) is selected (default), you will lose all the references to that variable.

Let us take a scenario where you had a Door model, placed it as a cell, then you (or the administrator in your organization responsible for maintaining cell libraries you use) edited the original model to include a knob and maybe added a variable which controls the knob offset. In this situation, you can update your cell definition (and cell elements) to reflect these changes by using Update Parametric Cell dialog. This dialog will help you remap the variables and variations of the outdated wooden plank model to that of the updated door model as below:

Search and Sort Variations in Properties Dialog

You can now search for variations and sort them in an ascending and descending order within the Properties Dialog. A list of variations are listed in the drop-down menu to select from.