Polylines and Splines get an Overhaul…


Have you always like the capabilities of using Polylines and Splines because of being able to have them connected as one entity, but hated to have to go through the maze of editing options to modify them later? Good news, they have added some great dynamic grip editing to Polylines that let you edit them similar to the boundary lines of hatch. You simply use the new edge grips in combination with the control key cycle through to add new vertices, or convert them into Arcs with out having to redraw them. Even Splines have added more functionality by being able to add “kinks” for a sharp corner. But that is just a few things that have happened to Polylines and Splines, so let’s take a deeper look into each one of these modified commands.

Polylines

Polyline objects in AutoCAD 2011 now have extra grips to make editing them easier than ever. In addition to the familiar primary grips located at the end of each polyline segment, there are now additional secondary grips located at the midpoint of each segment. These grips, like the new Hatch grips, are multifunctional. The available functions can be seen by hovering over a grip, and you can choose an option directly from the menu that appears.

Direct manipulation polyline tools

You can also activate the grip by clicking on it. Then you can cycle through the available functions by pressing CTRL, or choosing one of the options from the right‐click menu. Icons next to the cursor indicate the active function. Sub‐selection for polylines has been refined in AutoCAD 2011. To sub‐select one or more segments of a polyline, hold down CTRL while left‐clicking on the polyline.

Polyline sub‐object selection

Grip behavior for sub‐selected segments is identical to the behavior when the entire polyline is selected. You can now use the JOIN command to connect lines, arcs, and polylines to 3D polylines, as long as they are all contiguous (in other words, they share a common endpoint). You must select the most complex object first (in this case, the 3D polyline), and the objects to be joined do not need to be coplanar.

Splines

Splines have been updated in AutoCAD 2011 to provide more flexibility and control. You can define a spline using fit points or control vertices (CV). CV splines are more appropriate if you will be using them with 3D NURBS surfaces.

Fit spline and Control Vertices spline

When drawing a fit spline, you can specify additional settings for its start and end tangencies, tolerance (how close the spline must come to the fit point), and knot parameterization (controlling the shape of the curve as it passes through the fit point). The only option for CV splines is Degree, which controls how many bends the spline can take in a given span.

CV spline Degree C

Easily switch methods, add and remove points, or edit endpoint tangencies using intuitive grip menus.


Spline tangent direction

The SPLINEDIT command also has several new options, including improved Edit Vertex options. You can now easily add “kinks” or sharp corners to a spline.

Spline kink

You can use the JOIN command to connect lines, arcs, polylines, 3D polylines, and helixes to splines, as long as they are all contiguous (in other words, they share a common endpoint). You must select the most complex object first (in this case, the spline), and the objects to be joined do not need to be coplanar.

So there you have it, useful tools that are easy to use and not hard to modify. I sure you will enjoy these new enhancements, and especially enjoy not having to use explode any more. I’m Isaac saying have fun, and thank you for your time.

Isaac is the go-to guy for the AutoCAD skills that lie at the foundation of AEC software tools and increased productivity. And you’d be hard pressed to find someone who knows more than he does about how to be more efficient in AutoCAD. Isaac can present best strategies and tips for productivity because he understands his audience and what they do. He has a high number of repeat customers who like his dynamic style and keep returning to learn more from him.

2 thoughts on “Polylines and Splines get an Overhaul…

  1. Can you explain step by step how to add kinks? I’m using 2013 but I”m sure it’s the same. I’ve followed the steps I have in my text book and nothing happens. Is there a special way to exit to get it to create the kink once the points on the spline are marked?

  2. Hi Debra, Sorry for the delay, (they only let me out of my box once in a while.) When you do the SPLINEDIT command, Choose Edit Vertex, and then ADD, Now pick the Vertex (blue dot) and it will kink it at that point. Now you must out by just hitting the enter key (since it is the default) until the SPLINEDIT command is completed. I hope you were able you get it to work prior, if you still can’t let me know.

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