how do I add nodes to a polyline?

Hi,

I found when I searched under "grips and nodes" the question posed

"How do I insert a new grip or node in to an existing polyline? "

and the answer

"PEDIT command"

now

my question is this: what do I do to add more nodes with the PEDIT command options?

we are using 2005 auotcad.

if this works it will save my boss a huge amount of time....

Have you tried the PEDIT command?

Just follow the prompts.

Pedit, select your polyline, Edit, Insert.

rkmcswain,

In PEDIT

The only option ( that I see ) under edit is , edit vertex, when I did that and then inserted, my whole line moved when actually I just want to add more nodes and not move anything....

...when I did that and then inserted, my whole line moved when actually I just want to add more nodes and not move anything....

Then pick your new points on the polyline. Use the NEA object snap.

If you are trying to densify one or more polylines, then you will need to purchase or write your own routine. By densify, I mean adding many vertices based on some criteria, like one vertex every "X" units, or "X" number of vertices total in a given polyline...

Author Message

rkmcswain

"If you are trying to densify one or more polylines, then you will need to purchase or write your own routine."

that's exactly what I'm trying to do.

By purchase a routine , do you mean purchase a program that layers the nodes close together? And by write my own routine , you mean that I would hand click each node so that they are layered so close together?

you could try dividing the original polyline into however many nodes you want, this will give you points that you can then draw a new poly line between from piont to point,

Hi!

I've got another idea..

Use break command to divide and then pedit to join together and you'll have vertex in every break point.

Przemo

Yedan & Pefi,

what I'm looking to do is have as many nodes as I can, layered as closly together as I can.

Our Cnc machine is half way broken and doesn't understand curves right now. The only way the machine can draw a curve is by reading where the nodes are placed . If there is a gap in the nodes that peice of the wood doesn't get cut.

Right now we are drawing in autocad and then having to transfer the image to another program that places the nodes as close as it can together.

I'm trying to cut out that last step. Each of these suggestions would work in there own way but it's still more work than transfering to the other program.... I'm hoping to be able to find something in autocad that allows me to automaticly have those nodes placed there ; laying there as neighbors as close as can be for a clean cut...

Yedan & Pefi,

 

what I'm looking to do is have as many nodes as I can, layered as closly together as I can.

Then you are looking for a "densify polyline" routine. You should have stated this up front instead of saying "How do I insert a new grip or node in to an existing polyline?" - which made it look like you only wanted to insert a single node on a single polyline....

This functionality s not included with vanilla AutoCAD.

You need a 3rd party routine.

You can write something yourself if you are so inclined, or purchase a supported program, or look for an unsupported freebie.

Here are a few of leads:

http://www.dotsoft.com/polylinetools.htm

http://www.4d-technologies.com/geotools/manual/polyline_tool_set_1.htm

http://tinyurl.com/eqffn

rkmcswain,

I misunderstood what my boss wanted me to find out originally, I guess that's what being human is all about; learning

thanks for the links and thanks to all who contributed their knowledge and time

I misunderstood what my boss wanted me to find out originally

No problem. Post back after you find a solution so we will know what worked for you.

http://www.4d-technologies.com/geotools/manual/geotools_manual.htm

"...This command can be used to add extra vertices into polylines based on a specific inter-vertex distance. After running GT_DENSIFY, there will not be any two vertices in the polyline spaced apart farther than the value specified in (1) below...."

150 $ if you need it fast...

Przemo

rkmcswain & pefi

I checked out several of the sites, they look promising.

I've gotta check with my boss about accually buying a program though, you know money and all that stuff..

Thanks for the help

A "poor man's" approximate method might work for some applications:

Use the "measure" command, where the block is a very short line segment aligned with the polyline. Say you want vertices at increments of 0.1, your block would be a single horizontal line 0.1 long, base/insert point at middle of line.

After measuring the block along the polyline, at a spacing equal to the length, explode all the blocks back to line segments.

Edit line segments as needed at ends of polyline and sharp corners.

Join lines into a single polyline using PEDIT>>Multiple>>Join with a fuzz factor of say 0.01 or more as needed and segments will join into a single polyline.

i guess this will depend if the pline is meant to be 'curvy' but here's something you can try...

make sure the pline is a bit longer then what you need...in the pedit command "Spline" it if it hasn't been done already...then draw a line near the end to trim the polyline...once trimmed you will notice that the polyline has many more vertices...this is also true if you offset a 'splined' pline too...

if the 'resolution' needs to be denser select the pline, pedit, 'Decurve' and then 'Spline' it again...do another trim and you will note even more vertices...it is important to decurve it first and spline it again or else the trim function will not add any more vertices...

i guess if it's a closed polyline then a combination of pedit/spline/exit... offset...pedit/decurve/exit...pedit/spline/exit...offset would also do the trick... :wink:

ps. i'm an up-to-acad 2002 user but trust it works w/ newer versions but you never know...

just be carefull as i know CNC programs dont like splines.

I know in some cases even polylines can pose an issue.

We run a Biesse CNC router. we draw up the requireed shape, then export it out as a dxf [v12] and then tool it up using Biesse's Edit Tech program.

Issues we have come across are things like text. CNC machines like Points of reference, Radius and Arcs. Trying to get a curved shape using a poly line can be done provided you use the ARC option when you draw the polyline.

Post up a pic on what your doing. it would be good to see what your tryig to do

G

Anna,

you can always replace the curved portions of the Polyline by lets say 1000 side polygons. Use the center of the Arcs to center the polygons, cut them, then explode the polyline, erase the real arcs and join the new geometry wit PEDIT Join.

I use this technique when I try to create a circular wipeout since it doesn't allow arcs for this kind of objects.

Cheers.