topic Re: How do I measure the loop length of a 3D Sketch and set it as a parameter? in Inventor Forum

How do I measure the loop length of a 3D Sketch and set it as a parameter?

JohnRambo4 — Fri, 12 Sep 2025 18:49:25 GMT

How do I measure the loop length of a 3D Sketch with splines and set it as a parameter? For example I want the total length of a hose to be saved as a parameter to show up the Description or QTY field on a drawing. Obviously you can measure it with the Measure tool, but how to set the length to a Parameter? Thanks.

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

kacper.suchomski — Fri, 12 Sep 2025 18:57:40 GMT

This is a question for @bradeneuropeArthur

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

andrewiv — Fri, 12 Sep 2025 19:15:42 GMT

You will have to have an iLogic rule to accomplish this. Here is a rule that used to use for this exact purpose. I would set this rule to run on the geometry change trigger.

Dim oDoc as PartDocument Dim se As SketchEntity3D Dim oParameters As Inventor.Parameters Try oDoc = ThisDoc.Document se = oDoc.ComponentDefinition.Sketches3D("3D Sketch1").SketchLines3D(1) oParameters = oDoc.ComponentDefinition.Parameters oParameters.Item("HOSE_LENGTH").Value = ThisApplication.MeasureTools.GetLoopLength(se) Catch Ex2 As Exception MessageBox.Show ("ERROR, HOSE LENGTH VALUE WILL NOT UPDATE" & vbCr & vbCr & vbCr & Ex2.Message, _ "SKETCH LOOP LENGTH ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error) End Try

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

johnsonshiue — Tue, 16 Sep 2025 03:56:49 GMT

Hi! Another approach is to use an iLogic rule to get the volume of the tube and divide it by the tube cross section area. The result should be the length.

Many thanks!

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

JohnRambo4 — Tue, 16 Sep 2025 12:41:11 GMT

This worked. I just needed to create a HOSE_LENGTH parameter before running the code, and checking the Export box in Parameters. Now I can have the length populate in the part description. Thanks. How do I get it to auto update on geometry change?

Strange there isn't a way to dimension the whole length in a sketch but whatever.

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

bradeneuropeArthur — Thu, 18 Sep 2025 20:02:32 GMT

Would something like @kacper.suchomski may mention help you?

https://youtu.be/zN06eaBr2eY

And please vote the idea if you think this is a good addition for future releases of Inventor.

https://forums.autodesk.com/t5/inventor-ideas/sweep-length-to-parameter/idi-p/13005488

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

JohnRambo4 — Thu, 18 Sep 2025 20:04:15 GMT

That tool looks great. Did you make it available somewhere?

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

bradeneuropeArthur — Thu, 18 Sep 2025 20:17:11 GMT

Could you send me a private message maybe we can have a look at the possibilities.

Re: How do I measure the loop length of a 3D Sketch and set it as a parameter?

andrewiv — Thu, 18 Sep 2025 23:09:18 GMT

To have it update whenever the geometry changes you just have to add the ilogic rule to the the event triggers. Just put it under the part geometry change trigger and then it will update the parameter any time the part is changed.