## Constructing a Curve

Construct Curve dialog box

There are two types of constructed curves (Independent Curves and Dependent Curves) available in PC-DMIS. The following table displays the two curves, along with their necessary inputs. All curves require a set as input. The set can be a measured set, a constructed set, or a scan. The input set must contain at least four features (or input points in the case of a scan).

CONSTRUCT FEATURE TYPE | SYMBOL IN EDIT WINDOW | # OF INPUT SETS | INPUT #1: | COMMENTS
Dependent Curve | DEPENDENT | 1 | Set containing at least 4 inputs | Curve will update as input feature changes Note: Editing a curve will change dependent curve to independent curve.
Independent Curve | INDEPENDENT | 1 | Set containing at least 4 inputs | Uses input feature for construction only. User can manually edit control points of curve.

The Edit window command line for a sample Curve Construction using a dependent curve type would read:

feature_name | =FEAT/CURVE, DEPENDENT, num_control_points, num_input_feats, thinning_parameter CONSTR/CURVE,INPUT_TYPE, input_id

For an independent curve type the Edit window command line would read:

feature_name | =FEAT/CURVE, INDEPENDENT, num_control_points, num_input_feats, thinning_parameter CONSTR/CURVE,

num_control_points = This is the number of control points defining the curve. More control points allow the curve to more closely pass through the features, but too may cause unexpected behavior

num_input_feats = This is the number of features that the curve is attempting to fit.

Note: These two parameters are not editable in the Edit window.

input_id = This is the ID of the set containing the features to be fitted.

thinning_parameter = This is described in the "Thinning Parameters" topic described below.

Note: The actual Edit report will be displayed in all CAPS

More:

Constructing a Dependent / Independent Curve

Determining the Length Between Two Points on a Scan