Constraining lines to a spline

The Point-on-Curve Constraint command enables you to constrain entities in a profile such that a selected point lies on a target curve. The following steps give a quick introduction to the command. This procedure tries to attach 3 lines to 67 a spline, where 2 lines are attached at each ends of the spline while the third line is at an arbitrary position on the spline.

1 In the profile mode create 3 lines in any random order. Do not pre-select any line. Also create a spline curve using Insert Curve Control Points.
 
2 Start the Point-on-Curve Constraint command —  Insert Profile Point on Curve.
 
3 From the selection list of the command, select the sequence to Multiple.
 
4 Now, click on the spline curve, to select it. Select the Fix at Parameter option and enter 0 in the mini dialog box.
 
5 In the selection list another selector — Point — will appear. Click an end point of a line you have created. We are going to snap this line to the start point of the spline.

Note
Please note that the Fix at Parameter mini-dialog box might hide the point you need to click at. In that case hit the F7 key to temporarily hide the mini-dialog box, perform your selection and hit F7 again to unhide the mini-dialog box (see Hide Minidialogs for details).

6 The Point on Curve constraint is now applied. The line is attached to the start point of the spline.
 
7 Change the value for Fix at Parameter to 1 and select one end point of the second line you have created. We are going to snap this line to the end point of the spline.
 
8 Change the value for Fix at Parameter to an arbitrary value between 0 and 1. Let it be 0.35.
 
9 Select one end point of the third line you have created. We are going to snap this line to a point on the spline where its parameter value is equal to 0.35. Note that this will be a "near middle" point on the spline.


 

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