Expand stroke alters pressure stroke

[mar&co]

I am trying to expand a pressure stroke. The result looks different from the original.

In the upper rectangular you see the original strokes in vector and outline viewing mode. In the lower rectangular is the result after applying Layer/Expand Stroke command. I expect both to be visually the same. The result though is much slimmer graphic element after expanding the stroke.

 

[Sean P]

Hi mar&co,

Would you be able to attach a copy of the strokes you're trying to expand please?

[Mihkel]

I have exactly the same issue, on MacOS and iPad. 

To reproduce on iPad (because there I can apply pressure with pen):

1. create a file
2. select vector brush tool
3. from Brushes select Pens > Solid pen with pressure (must be this one, most other brushes are not expandable and do not give any feedback on that so heres actually another issue )
4. set Controller to Brush defaults
5. draw a stroke with varied pressure
6. tap on the ... menu button and select Expand stroke
7. toggle undo-redo to see the difference in width, zoom in to see it better

This also affects svg export where lines drawn with "Solid pen with pressure" are automatically expanded and show up thinner in the exported file – badbadbad .

I tried expanding the stroke both on iPad and on Mac – same results.

If I draw with mouse (no pressure) on my Mac or on iPad with Controller set to None then the stroke expands correctly. So surely related to pressure.

[MEB]

Hi Mihkel,
Welcome to affinity Forums
Thanks for your report. This is a known issue that's already logged to be looked at.

[Mihkel]

great, looking forward to the solution

[reneromero08]

This happened to me also while working with a client. I still don't know how to solve it, they need the vector file but I must expand my strokes! I hate going back to Illustrator!

I painted some hair brush strokes with pressure on and expanded stroke. Then used the add function and it got even worse!

Is there a legacy version that works? I needed this yesterday :s

I took screenshots but the attachment button is stuck on loading.

[Mihkel]

One solution would be to just try to figure out how much the line with shrinks when expanding. Then create a copy of your design, make the strokes wider by the amount they shrink during expanding and then expand. Should work in theory. If there are multipls stroke weights involved and you do not want to scale them one by one then you can play with scaling the whole artwork up and down while playing/toggling with scale stroke with object option. Should work in theory...

[jdkn]

The difference in thickness between the desired and expanded curves is neither constant nor proportional to the thickness of the desired curve. See screenshots pre and post expansion, source afdesign file attached:

It's also interesting to me that this curve doesn't taper down to 0 width, since the pressure profile does. This curve was created with the vector brush tool and then modified. The same curve created with the pen tool with the same pressure profile does taper down to zero width and does expand properly.

expand_stroke_pressure.afdesign