Using Parametric Design

Using the parametric design environment consists of several basic steps:

1. Load a parametric template file, including browsing for a design.
2. Select an object or objects.
3. Select parameters, either from the design editor or the CAD view.
4. Altering the parameter values.
5. Unfold the design (modify the layout if required).
6. Generate output - via printing, CAD export or file output.

One or all of the objects in the design may be preselected, depending on the options settings. When an object is selected it is normally colored white and when unselected it is colored red. When an object is selected all parameters (i.e. dimensions) associated with that object appears in the property editor (to the left of the main wiindow). Individual objects can be selected either using the mouse cursor to point to objects or by using the drop down combo box on the command dialog panel. If an object is selected via the combo box then this becomes the only selected object in the view. If the mouse pointer is used in the CAD view then the nearest object to the mouse click (within a tolerence) is selected. This has the effect of toggling the selected state of the object. If the object is initially unselected then it becomes selected, and if initially selected it is unselected. At any time all the dimensions (or dimension groups) relating to the selected objects appear in the property editor.

The parameters in the property editor appear in groups, denoted by a small '+' or '-' to the left of the group name. The parameters are grouped into 'object group' parameters associated with the individual selected object only, and 'link group' parameters that apply to the relationship between the selected object and another object to which it is connected. Where a connection exists both objects may have a 'link group' relating it to the other. They may also hold similar parameters (e.g. both may have a Beta angle for the relative angle of each object to the other). However the parameters in a link group tend to be directional. The object owning a link group tends to treat itself as the datum and any alteration of a link dimension moves the other object relative to it (in cases where movement occurs), so the two link groups are fundamentally different even though they represent the relationship between the same objects.

To see the actual parameters in the groups it may be necessary to expand the groups by clicking on them in the property editor. Clicking on the group opens up the group so the parameters become visible (or close it if already open). Also if there is a visible dimension associated with a parameter the dimension will appear in the 3D view. A parameter can be selected for modification by either selecting it in the property editor, or by selecting the dimension associated with it in the 3D view. When the dimension is selected it becomes the currently editable parameter in the property editor and the highted dimension is the CAD view. Normally highlighted dimensions are colored yellow and unhighlighted colored cyan (light blue). Only one parameter/dimension can be selected at any one time.

Parameters are altered by simply typing new values into the property editor and pressing the enter key. The altered dimension may adjust the objects size or position. Each time a parameter is altered the whole design is rematched according to its match relationships. This means parameter values may be automatically adjusted to maintain the matching state of the connected objects. The match settings of a parametric design cannot be changed or interrogated using the Lite version of the software.

When a value is entered the design in the 3D editor is automatically updated to reflect the change. If the change was large then it may be necessary to zoom the view to the extents to make the design centrally visible in the view (press F2). Alternatively an option can be set to force the design to Auto Zoom each time a parameter changes. By default the Auto Zoom is turned off because it is easier to appreciate the effects a parameter adjustment if the view scale does not change.

Another option exists to Reweld a design when a parameter changes (Parametric Reweld option). If this option is not set then all objects always return to their Outline form when a parameter value changes. If set then the design is rewelded and displayed in Welded form. A further option exists to limit the time taken to regenerate the welded design when a parameter changes. If the design takes longer than the set period (default 3 seconds) then the design is returned to Outline form for purposes of efficiency.

In a complex design if all object are selected at the same time the view can appear cluttered and confusing. In most cases it is better to select one object at a time to keep the view clear. The easiest way to do that is to select the object using the combo box on the left of the dialog panel.

Conversion Of Units

The original size of a parametric design many limit its use in other units. For example a design originally create in millimeters may be well oversized for specifying parameter values in inches. In these cases use the 'Scale' command in the Tools menu to alter the overall initial size of the design. For millimetres to inches a scale factor of 0.04 should be used. Or from inches to millimeters use a factor of 25. This effectively gives a coarse adjustment. Typing in the parameter values will then give the fine adjustment of the design.