Curves WB: Map sketch on surface

[drmacro]

I get, to me an unexpected result when I use Map sketch to surface.

I padded a cylinder and made a sketch of a hexagon. Selected them and clicked Map sketch to surface.

The hex is the correct shape. But, why is it below the cylinder (-Z)?

HexOnSurface.png (30.79 KiB) Viewed 640 times

[Chris_G]

Because your surface is parametrized in [-100, 0] in V direction :

Code: Select all

>>> f1.ParameterRange
(0.0, 6.283185307179586, -100.0, 0.0)

The easiest way to use this tool is to simply select the target face and activate the tool.
Since there is no sketch selected, it will create a default one, with the face boundaries included.

[drmacro]

Because your surface is parametrized in [-100, 0] in V direction :

Code: Select all

>>> f1.ParameterRange
(0.0, 6.283185307179586, -100.0, 0.0)

The easiest way to use this tool is to simply select the target face and activate the tool.
Since there is no sketch selected, it will create a default one, with the face boundaries included.

I'm a bit confused. where did the -100 come from, the padding of the circle? (and V direction?...)

And, if I select the surface of the padded cylinder only and activate the tool I get:

Code: Select all

onChanged : Sketch_On_Surface003 -> Proxy
Face update : (<PartDesign::Pad>, ['Face1'])
onChanged : Sketch_On_Surface003 -> ConstructionBounds
onChanged : Sketch_On_Surface003 -> Scale
onChanged : Sketch_On_Surface003 -> Label
Part::FeaturePython / Sketch_On_Surface003: Links go out of the allowed scope
***** execute *****
Sketch bounds = (1.7976931348623157e+308, -1.7976931348623157e+308, 1.7976931348623157e+308, -1.7976931348623157e+308)
Face update : (<PartDesign::Pad>, ['Face1'])
Surface bounds = (0.0, 6.283185307179586, -100.0, 0.0)
to2D : []
onChanged : Sketch_On_Surface003 -> Shape
<Part> ViewProviderExt.cpp(1324): Cannot compute Inventor representation for the shape of HexOnSurface#Sketch_On_Surface003
----- execute -----

[Chris_G]

OK. I just pushed a couple of fixes.
Please update Curves WB and retry.

[drmacro]

OK. I just pushed a couple of fixes.
Please update Curves WB and retry.

How does it know which sketch to map...

Cuz, I updated Curves, and no error, but the Mapped_Sketch is empty...

[Chris_G]

It should contain Construction Lines that are the face boundaries.
Then you can add some geometries, that will be mapped on the face.

[drmacro]

It should contain Construction Lines that are the face boundaries.
Then you can add some geometries, that will be mapped on the face.

So, I don't create a sketch and draw what I want, then activate the tool?

Different topic: With the new version. I selected the face of the cylinder and activated the tool. Now I see the construction loines you note when I open the resulting sketch.


Also, the boundary construction lines are 100mm x 6.28319mm (The later remarkable close to 2PI...) The cylinder is 100mm tall, but 2PI?

[Chris_G]

Easiest workflow :
- select target face in 3d View
- activate tool
- 2 objects are created : Sketch_on_Surface and Mapped_Sketch
- edit Mapped_Sketch to add geometries

Also, the boundary construction lines are 100mm x 6.28319mm (The later remarkable close to 2PI...) The cylinder is 100mm tall, but 2PI?

This the default parametrization of cylinders in FreeCAD ([0, height, 0, 2*pi])
But if Scale property of Sketch_on_Surface is True, you can resize the blue boundary box of Mapped_Sketch to your liking.

[TheMarkster]

This the default parametrization of cylinders in FreeCAD ([0, height, 0, 2*pi])
But if Scale property of Sketch_on_Surface is True, you can resize the blue boundary box of Mapped_Sketch to your liking.

Can also add construction lines as boundaries on pre-existing sketch?

[Chris_G]

Yes. And set Scale and ConstructionBounds properties to True.