Terminology

Parametric Patterns

Parametric Patterns are patterns that are based on variables. Some pattern dimensions are set equal to a variable, while some will be more advanced, using equations and expressions to relate dimensions to variables.

Template Points

Each start, end, or insertion point becomes a Template Point. Users can attach controls between any Template Points.

For convenience, interior points on polylines and splines are not normally used as Template Points. This lets Templates replace splines and polylines with their geosim after the endpoints have been re-positioned. If you want to add controls to interior points, go to the Controls tab and click on Expose Interior Points.

Controls

Controls are the instructions users will either attach to Template Points or between Template Points. Controls can be associated with a Variable or Parameter.

Expressions

Expressions are algebraic equations associated with parameters.

Variables

Measured values that the finished patterns need to fit. These are the simplest, lowest level of control measurements, usually measured in the field on a physical object.

Text inside a pattern can be used as a variable, allowing you to change it when you generate new patterns. Put your text inside angle brackets (< >) and Templates will automatically add it to your variables list.

Parameters

A Parameter is the name given to a control. It can then be associated with a constant or an expression to determine its numeric value.

Positioners

Controls will generate dX, dY, or dD Positioners on template points. The positioners are used by Templates to move template points to their new position based on the current values of the variables.

Degrees Of Freedom

Degrees of Freedom for a coordinate system refers to the number of directions a point can move independently. A point in a 2D plane can move in X without affecting its Y value, or in Y without affecting its X value, giving it two degrees of freedom. Alternatively, you can substitute Distance from another point for one of those directions (X or Y). The possible combinations of degrees of freedom in a plane are:

Each Template Point starts with two available Degrees of Freedom (DoF). Each Control that ends on a Template Point reduces that point’s DoF by one. No more than two Controls can end on a Template Point. 

Each control’s endpoint will move that point in the X, Y, or Distance from the startpoint direction. More than one control in the X or Y direction would conflict with each other, so Templates won’t allow that. The possibilities for any Template Point are:

There is no limit to the number of Controls that can start on a single point.

Geosim

Geosim stands for Geometrically Similar. A geosim is a copy of an element with the same geometrical properties as the original, with a different overall length.