New parametric design templates can be created using the 'File|Convert to Parametric '
command in the
3D CAD designer menu. This command converts the current 3D CAD design into a parametric design and
copies it to a new parametric design window.
A new parametric design has parameters attached to the design and grouped into object groups and link
group. Each object has its own object group and a link group for each object to which it is linked. The
object group holds parameters that are specific to the individual object and independent of any other
object (e.g. section diameters, length etc). The link group holds parameters that apply to the relationship
between the object and the linked object (e.g Beta angle - relative angle, Offset - center line offset).
Some parameters are associated with a visible dimension that appears in the CAD view. Others have only
the numeric representation and don't appear in the CAD view at all.
The parameters that appear in a converted design are those that survive the automatic parameter
filtration process during conversion. The filtration rules determine which parameters survive. After the
conversion it is then possible to manually filter out even more of the design parameter until the parameter
set is reduced to those required to define the particular design. Having completed the manual filtration the
new design would then normally be saved to a file, which may be an addition to the design library. These
parametric designs can then be re-loaded and reused as required. All designs in the parametric design
library were created using this process.
Parametric Design and Matching
When a design is converted from a CAD design to a parametric design the matching
relationships that
have been established using the CAD system matching commands are preserved. Each time the user types
a new value into a parameter field the design is adjusted, then it rematches all matched objects using
these match relationships. Match relationships and matching options cannot be adjusted from the
parametric environment.
Conversion Rules
The conversion process applied by the program consist of analyzing the design and attaching all possible
parametric to the design. It then filters out all parameters that are determined to be irrelevant to the
design according to certain rules. To use the parametric conversion facility effectively requires some
understanding of these rules used to make the conversion.
Generally these rules are as follows:
1. Some parameters are filtered out when they have a value of zero.
2. Some parameters are filtered out when they have a non-zero value.
3. Some parameters are filtered out when they have an equal value to another parameter.
4. Some parameters are filtered out when they are not equal to another parameter.
5. Some parameters are included only if another parameter has been filtered out.