Align Polyline onto another polyline

[tpcc79]

Hi

Was wondering if anyone knows a way I can align a new polyline to a reference polyline (orig polyline).

The 2 polys will be generally the same length, however, the number of vertices will differ.

Also I need to mantain the same distance between the vertices on the new poly and the new and reference poly won't follow the same direction.

Looking for any help thats out there.

Thanks

[gjrcmb]

See if the ALIGN command will do what you are looking for?

[tpcc79]

No the align command is for a simple straight line adjustment. This isn't what I'm doing.

I'm looking for a way for the the new polyline to 'lie' directly ontop of the reference poly, without the overall length of the new poly changing and the distances between distances between th vertices staying the same.

[Joe-Bouza]

read the command line and answer in the negative to scale objects

[tpcc79]

Once again, it is not a simple straight line adjustment, so the align command doesn't suit.

The 2 polys are generally the same length, with different numbers of vertices and different distances between vertices.

I need the new polyline to align - as close as possible - to the reference poly in all directions and at all vertices, not simply the start and end points.

[gjrcmb]

The parameters, criteria, and how you would go about implementing a solution seem pretty confusing.  Depending on the polylines you are wanting to align to each other the parameters change,  so how do you define a standard way of handling it, even if the polylines are somewhat similar.

So I think that maybe you have to take a stepped approach.  Just speculating here!  Maybe you could use the "Create Line By Best Fit" to fit a line through each polyline possibly using the regression analysis to adjust the fit, then use the "Align" command to align one polyline-fitted line set to the other by using the fitted lines, and then move or adjust one of the polylines along the Align fitted line so that the beginning or ending match up the way you want to.  Does that make any sense?

If not perhaps a drawing would help?

[Joe-Bouza]

How bout a picture?

When you say align, the inference is that you want to correlate two or more points in space to two or more point in a different space that share congruency. If the poly lines are not congruent then how can you expect them to align?

What are you asking to do? Post a picture

[Chasethewind]

I have this exact situation, and would like to know if there is a way to accomplish this task.  Here is a pic.

The polyline that is gripped needs to be aligned with the red line.  I typically grab the grip and move it perpendicular to the red line.

Note*  I am aware of the straighted command under pedit, but that removes verticies.

Thanks

[Joe-Bouza]

If I understand correctly, the only way I know is manually:

Lets take the left side first: Hot grip your linefrom the vertice on the red line away from the arc, when you get to the end hold the last grip with the ctrl key; now pull the last grip toward the red line. If the line is equal to or less than the red line snap to it. If your line is longer than the red line: use the extension snap or draw a construction line before you begin.

Why is it not easier to redraw this geometry?

[BrianHailey]

Oh! I wish I had Civil 3D on this computer, it would make answering this so much easier!

Let's see if I can find the command in the help system...

Here we go, perhaps THIS will help you out.

[autoMick]

So have I got this right? You want to:

- determine the distance between each vertex on your original polyline

- scale these distances, so that the total length is the same as your target polyline?? Or keep them the same? (is the target polyline always longer than the original ?).

- then draw in vertices on your target polyline at the scaled distances determined in the steps above?

what about vertices that already exist on the target polyline?

I don't have an exact solution, but I can't help thinking that the solution is somehow going to involve creating alignments from the polylines and using station distance to create the new points.

[fcernst]

"I typically grab the grip and move it perpendicular to the red line."

Is this what you are looking to do? Perpendicular projections of the polyline vertices, that are then used to create a new polyline on top of the reference polyline?

[Chasethewind]

The link only goes to the help menu in Civil3D 2012.  Can you tell me what command you found please.

The gripped line is actually a shape file that I have to edit, so redrawing the shapefile is out.  I would lose too much information the field crews collected.

Cory

[Chasethewind]

"Is this what you are looking to do? Perpendicular projections of the polyline vertices, that are then used to create a new polyline on top of the reference polyline?"

This is what i would like to do, but I do not want to create a new polyline, I want to have the original line "Projected" to the reference line.

Cory

[fcernst]

If you guys have to do this frequently, I would recommend contacting Terry Dotson at DotSoft, this routine is right up his alley of offerings.

[david.zavislan]

Map 3D (and Civil 3D) has a rubber-sheet transformation command:  ADERSHEET.  It allows the selection of multiple from-to point pairs. 

[Chasethewind]

This command is similar to what I want, but still I have to select every vertex and tell it to go perpendicular to the reference line.  Unless I am missing something.

Cory

[TerryDotson]

Thanks, I've began experimenting with some geometry based on Chasethewind's ALIGN.JPG.  If I understand correctly, the points of the original polyline (black) would be projected to the red polyline and would take on the locations of the circles.  The bisector of two vertices would determine the direction, then intersect at the target vector.

If this is all there is to it, it's about an hours work.

[fcernst]

Yes, move the vertices on the original polyline to the projected locations on the target polyline.

Would want to do all this, in only two-clicks, one click on each polyline.

[TerryDotson]

After some thought, the tool needs a Perpendicular option as well.  So you could use Bisector/Perpendicular.  Yes, two picks would do it and it's not radically different than our existing Polyline Midway tool.