Variable Formulas

In this Task

• A dimension will been added and a Formula controlling its relationship to other constraints will be added.

 

Before you Start

• Auto Constraints activated. See bottom left corner of graphics editor.

Take Note

• Updates to variable values may conflict with other variables. Always input variable values which make good design sense.
• Menu options for the Default menu and workspace, the Ribbon and Palettes are provided directly under the Command Name heading.

 

Variable Formulas

Calculator Palette

Formulas are used to define the relational values between objects and to create predictive behavioral patterns when associated constraints are modified.Simple formulas are used to fix an object’s position in relation to other objects and are commonly referred to as a Design Rule.

 

Using the Orthogonal dimension tool, insert a horizontal dimension shown in the illustration below. Take care to insert this dimension from the left vertex to the vertex defined by the constrained point in the center of the arc.

Dimension vertex to vertex

This dimension will now be displayed in the Variables palette as Var5. The design rule of this constraint is that the center of the circle must always remain one third of the overall length distance, regardless of what that may be.

Click into the Formula field next to Var5 and input =Length/3. This will maintain this relationship after the Length variable is changed.

Creating a formula for a variable

To test this, in the Variables palette, change the Length variable from 120 to 150. The new variable automatically retains its relationship to the Length variable, shown below.