## Constructing a Line Feature

Construct Line dialog box

There are many methods to construct a line using PC-DMIS. The following table lists the various types of constructed lines, along with their necessary inputs. Some features may require no inputs while others may require three inputs or more. The term 'Any' in the table below indicates that the construction can take any type of feature as input for construction. PC-DMIS allows the features to be selected in any order.

CONSTRUCT FEATURE TYPE | SYMBOL IN EDIT WINDOW | # OF INPUT FEATS | FEAT #1: | FEAT #2: | COMMENTS
Alignment Line | ALIGN | 0 | - | - | Constructs line through alignment origin
Best Fit Line | BF | At least 2 inputs are needed. | - | - | Constructs best fit line using inputs
Best Fit with Recomp Line | BFRE | At least 2 inputs are needed. (1 must be a point) | - | - | Constructs best fit line using inputs
Cast Line | CAST | 1 | Any | - | Constructs line at centroid of input feature
Intersect Line | INTOF | 2 | Plane | Plane | Constructs line at the intersection of 2 planes
Mid Line | MID | 2 | Line, Cone, Cylinder, Slot, Plane | Line, Cone, Cylinder, Slot, Plane | Constructs a mid line between the input features
Offset Line | OFFSET | At least 2 inputs are needed. | Any | Any | Builds line through first feature and offset from second feature by specified amount
Parallel Line | PLTO | 2 | Any | Any | Constructs line parallel to first feature and passing through second feature
Perpendicular Line | PRTO | 2 | Any | Any | Constructs line perpendicular to first feature and passing through second feature
Project Line | PROJ | 1 or 2 | Any | Plane | Using 1 input feature will project line to work plane
Reverse Line | REV | 1 | Line | - | Constructs line passing through input with reversed vector
Scan Segment Line | SCAN_SEGMENT | 1 | Scan | - | Constructs line from a part of a Linear Open or Linear Close scan.

Note: If you select inappropriate feature types, PC-DMIS displays "Cannot construct [feature]. Combination of input features not accepted." on the Status Bar.

To construct a line:

1. Select Construct from the menu bar (Insert | Feature | Constructed | Line).

2. Access the Construct Line dialog box.

3. Input the desired features.

4. Select the method of construction. Available options include:

- Auto Line

- Alignment Line

- Best Fit or Best Fit Recompensate Line

- Cast Line

- Intersect Line

- Mid Line

- Offset Line

- Parallel Line

- Perpendicular Line

- Projected Line

- Reversed direction Line

- Scan Segment Line

- Offset Line

5. Click the Create button.

The Edit window command line for this option would read:
feature_name=FEAT/LINE,TOG1,TOG4
THEO/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,length
ACTL/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,length
CONSTR/TOG2,TOG3,...

If TOG2 = LINE and TOG3 = BF or BFRE then the command has the following format:
feature_name=FEAT/LINE,TOG1,TOG4
THEO/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,length
ACTL/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,length
CONSTR/LINE,TOG3
OUTLIER_REMOVAL/TOG5, stdDevMultiplier
FILTER/TOG5, WAVELENGTH=cutoffWavelength

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

TOG1 = POLR or RECT

TOG2 = LINE

TOG3 = ALIGN / BF / BFRE / CAST / INTOF / MID / OFFSET / PLTO / PROJ / PRTO / REV / SCAN_SEGMENT

TOG4 = BND / UNBND

TOG5 = OFF / ON

Length = This value represents the theoretical or actual length of the line.

stdDevMultiplier = This multiplier value determines whether or not a measured point is an outlier. If the point from the line is further than the standard deviation multiplied by this, then it is an outlier and will be removed if you have selected the Remove Outlier option.

cutoffWavelength = This value controls the amount of data smoothing. The longer the wavelength the more smoothing there will be.

The first three lines displayed in the Edit window will be the same for constructed lines. The fourth line will be slightly different, according to the type of feature being constructed. You can switch between the different types of lines by placing the cursor on TOG3 and pressing F7 or F8. (See "Command Mode Keyboard Functions" in the "Using the Edit Window" section.)

When two or more features are involved, PC-DMIS automatically determines the necessary order of the input features. This improves the accuracy of the measurement process.

AUTO is the default method of construction. See "Auto Line Construction" | The following topics describe the available options for constructing a line:

More:

Variations

Auto Line Construction

Constructing an Alignment Line

Constructing a Best Fit or Best Fit Recompensate Line

Constructing a Cast Line

Constructing an Intersect Line

Constructing a Mid Line

Constructing a Parallel Line

Constructing a Perpendicular Line

Constructing a Projected Line

Changing the Direction of a Line

Constructing a Line from Part of a Scan

Constructing an Offset Line