Change polyline/AEC Polygon origin point

[faugustom]

There is a way to change a closed polyline origin?

Context: I'm using Autocad Architecture AEC polygons to hach floor plans, but they don't have a good origin control. So for change a polygon origin, I could convert it to a polyline, set a new origin, and then convert back to an AEC polygon, this time with the correct point of origin.

- the origin point will always be in a vertex of the polyline;

- if I could change the origin of AEC polygon itseft it would be great! 

Thanks 

[john.uhden]

I'm guessing you meant hatch, not hach.

I've always been curious about changing the origin of a hatch (but never tried it via AutoLisp), which is what I think you want to do.  Polylines have start and end points (which would be the same if closed) but not origin points.  But of course you are using what we used to call Architectural Desktop or ADT, which like Civil 3D has a mind of its own and makes custom objects that hide any way to deal with them on your own except by changing some cumbersome style.

So, can you do a HatchEdit and change the origin?

[faugustom]

Hi John!

Hatch, that's it!

- the AEC polygons has a fill property, like a hatch, but can't be editet by HatchEdit;
- yes, the "origin" is the start/end point of the closed polyline;

When a polyline is converted to a AEC Polygon, it's fill property uses the polyline start point as it's origin; So, if I can change the polyline start vertex to another vertex, I can then convert to a AEC Polygon with a new origin for it's fill.

[faugustom · Accepted solution]

Thank you John!

Correcting the syntax, found the answer:

https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/change-polyline-start-point/m-p/2154...

[john.uhden]

That's a lot of code.

I recently wrote a POB program, which is a whole lot simpler than that.  It's at work; I don't have it here at home.

But my guess is that the AEC app won't let you treat the polygon as a polyline, in the same way that C3D won't let you programmatically alter components of its custom objects.  For your sake, I hope I'm wrong.