Curves - Map a Sketch on a Surface

[daffyduck]

Hello,

I am using FreeCAD 0.19 v24291 on Windows 10.

I am trying to project a curve onto a complete surface. I've researched the function a little and even found a Youtube video. However I am having no luck. I have imported a curve generated from a DXG and converted it to a sketch. I have also imported my mesh and converted it to a shape.

I cannot get past the error 'Part.LineSegment' object has no attribute 'Construction'

I edited the Sketch and bound it with a blue construction rectangle.

I've attached screenshots for reference.

Any help would be greatly appreciated.

Thanks.

[Cekuhnen]

the screenshot did not make it

[chrisb]

It sounds as if you need the Curves addon workbench and you should use the Map sketch to Face function.

[daffyduck]

Thanks for your replies. I have the Curves WB added.

I will try to add the screenshots again.

Best regards.

[daffyduck]

Workflow Steps:

• Import Mesh
  Create Shape From Mesh
  Import DXF (lines)
  Convert DXF imported BSpline(s) to Sketch
  Open Sketch
  Enter Construction Mode
  Bound Sketch with a blue rectangle
  Open Curves WB
  Choose the Shape and the Sketch
  Map a sketch to a surface
  Open Sketch properties
  Set support to be the Shape
  Set Map Mode to Deactivated

I've also tried different variations of this workflow.

Error is showing as a Popup in the first screenshot posted

[Chris_G]

At the end :
- Set support to be the Shape
Not the whole object ! You must select the target face in the 3D view.

[daffyduck]

ah ok. Thanks Chris_G. I have a lot of small triangles. Is there an easier way to select a region, other than CTRL+Clicking each triangle? I tried SHIFT+B with no luck.

[daffyduck]

If I understand corrrectly, I created a new test and replaced the SET SUPPORT TO BE THE SHAPE with one face. I still have the error. However I feel like I'm getting close!

[Chris_G]

A triangle is a face.
The sketch on surface tool can only work on a single face.
It cannot spread over many conitguous faces.
So it won't work on that kind of meshed input.
And the error message seems to indicate that your CurvesWB installation is not up-to-date.

[daffyduck]

I think it might be easier to explain what I am trying to accomplish. I am sure FreeCAD has a better way to accomplish my task.

What I would like to do is project a curve onto a surface. I could also create the curve directly onto the surface as an alternate approach. (A complex surface like shown in the attachment below. It is a 3D leaf). I would then like to export the projected curve as a DXF. Then I will import it into CAM software to create a tool path along the curve. I will engrave (shallow cut) along the extruded path to create the leaf "vein".

Is there a better approach to accomplish this task?

Thank you.