Dynamo Creates A Circle Out of a Curve


I have a Dynamo Script that should take a polyline, chop it up into sections, and then offset the sections to create a dashed line on either side of of the parent polyline. The script works great except if one of the chopped segments contain both a line and a curve; in this case Dynamo reads the segment as a line and circle. This is not the output I want. Is it possible to keep this geometry as curve?

Hi @mparks8G2XN,

Segments that only contain lines or arcs should be treated as curves, and then segments with a combination of the two should be polycurves. Are you exploding or otherwise breaking the curve down into its components before splitting?


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It’s one polycurve until it’s split. Below is the output.

Can you upload a screenshot of the graph?

You bet!

This is an issue with geometry scaling. As a rule of thumb, never change the geometry scaling from the default setting of “Medium” even though it gives you the warning. This issue comes up all the time using Civil 3D because we often work in real-world coordinates. Unfortunately, doing what Dynamo tells you to do can result in several issues when performing geometric operations including distorted solids, branching PolyCurves, etc. If you search around the forum, you’ll see numerous posts about issues that arise after changing the geometry scaling settings.

So you have a couple options:

  1. Leave the settings alone and deal with the warnings (most common)

  2. Use a Function.Apply node to effectively “swallow” the warnings

  3. Shift the Dynamo geometry closer to the origin, perform all the operations you need, then shift it back to original coordinates before sending to Civil 3D

  4. Upgrade to Civil 3D 2023, which ships with Dynamo Core 2.13 and gives the ability to dismiss/ignore specific warning messages


Gotcha. Thanks so much! I can live with the warnings.