### Constructing a Line from Part of a Scan

A line can be constructed from a segment of a Linear Open or Linear Close scan. PC-DMIS will create a line from part of the scan. The details of the construction are included further in this discussion.

To construct a Scan Segment Line:

1. Access the Construct Line dialog box (Insert | Feature | Constructed | Line).

2. Select the Scan Segment option.

3. Select a previously created Linear Open or Linear Close scan.

4. Click the Segment Data button. The Scan Segment dialog box will appear.

5. Select either the Best Fit or BF Recomp option.

6. Select the portion of the scan used in the construction from this dialog box.

7. Type the number of points to potentially discard by entering values in the Discard Start and Discard End Maximum boxes.

8. Type a distance from the best fit line into the Discard Tolerance box. This tolerance is a form tolerance; it allows you to control what end points are accepted as part of the line. If the distance from the scan point to the best fit line is greater than this tolerance value, then the end point will be discarded.

9. Input the Approximate Start and End Points of the scan by marking the Select Points check box, and then clicking in the Graphics Display window to fill in the X, Y, and Z fields. You can click anywhere in the Graphics Display window, however, PC-DMIS will place the point on the scan nearest to where you clicked. You can also edit the point values by using the keyboard.

10. Click OK to accept the data and close the Scan Segment dialog box.

11. Click Create to construct the line from the scan.

The Edit window command line for this option reads:

CONSTR/LINE,SCAN_SEGMENT,fit_type,feat_1,start_x,start_y,start_z,end_x,end_y,end_z,discard_start,discard_end,tolerance

If you want more than one arc or line from a given scan, then you will need to add another command for a different section of the scan.

More:

Determining the Data Used to Construct the Line