Issues with Extrude Along Path command

[symo]

Hi All

 

Im having a lot of issues trying to recreate this kind of shape using the Extrude Along Path Command:

I first start by creating NURBS curves for profile and path. Profile on the left, path on the right. I start by creating polylines, then convert to NURBS:

 

 

I then select both NURBS curves and select the Extrude Along Path command, but this normally fails:

 

 

I try to rotate the path NURBS curve so that it resembles the shape I want but this fails too.

 

Please let me know what Im doing worng, or if theres is a better way to do this.

 

Cheers in advance.

 

Symo

 

[markdd]

Here is my explanation. I should say that the direction of the path geometry is also important.

 

There are other ways to create the same 3D object using the Shell Tool and the Fillet Edge Tool but this should give you the techniques to complete the object you have shown in the image above.

 

 

 

 

 

 

 

Edited March 7 by markdd

[line-weight]

@symo the EAP tool can be quite infuriating, because when it fails it doesn't generally tell you what has gone wrong.

 

The VW documentation for it is rather poor:

 

https://app-help.vectorworks.net/2024/eng/VW2024_Guide/Shapes2/Extrude_along_path.htm

 

In particular it's very confusing to understand what those two tick boxes in the dialogue do

 

 

@markdd's video shows that you should tick the "fix profile" one. In the explanation above, what exactly does "the profile is moved and rotated with respect to the path" mean? There needs to be some clear graphical explanation of exactly what these tick boxes do. They are only very briefly mentioned at the very end of the video on that page but they are quite critical to whether the operation produces the intended result.

 

I'm going to tag @Kristin Bailey here because she responded proactively to another thread about help documentation. I've complained before about the EAP help page but with no response.

 

Going back to what was happening to your attempt, I think it was failing because without selecting that tick box, it'll try and run the "profile" along the "path" using the centroid of the "profile" as the point that intersects with the path. This produces self-intersecting geometry, which the EAP tool doesn't like.

[VIRTUALENVIRONS]

3 hours ago, symo said:

Im having a lot of issues trying to recreate this kind of shape using the Extrude Along Path Command:

Lots of great help here and knowledge on EAP.  I would suggest the main reason for your problem is your project is not really an EAP solution.  This is a 3D box, 3D fillet, Shell and finally split tool solution. 

Using the above tools, it would take under a minute to create the tube with the correct thickness.  The flange at the front would be a subtract solids operation or some other. 

 

There are many ways to make this.

 

EAP is a great tool.  Essentially loft with one rail, only more accurate.  As it can be used with almost anything that creates a path, it does not always respond the way you think it will.  That is probably because VW's converts the path to a NURBS curve and how it does that is up to the application.

So, I always start if I can with a NURBS curve.

[bcd]

1 hour ago, VIRTUALENVIRONS said:

I would suggest the main reason for your problem is your project is not really an EAP solution.

yes

[symo]

Thank you everyone for the very helpful responses. I can see now that the EAP command isnt the best way to go about my 3D shape. 

[symo]

Many thanks @markdd for that very helpful video, much appreciated.

[Kristin Bailey]

Thanks for tagging me in, @line-weight. I'm still doing some "re-entry" (AKA digging through piles of messages and prioritizing what's next) after some time off, but have also seen this issue discussed in-house. I'll add this to our to do list for help, and see what we can learn and clarify.

[VIRTUALENVIRONS]

So often I focus on the users problem that "I don't see the forest for the trees".  I imagine we all do.  I was working on something and I realized this could be an EAP solution if we just reversed the curves.  My "duh' moment below.