Inkscape.org
Beginners' Questions Trace Does Nothing
  1. #1
    MaxHugen MaxHugen @MaxHugen

    First time newbie. I imported a diagram, selected it in the new page, opened Trace, left settings as they were (single trace), clicked Update and then OK.

    Nothing seems to happen. Advice on what I'm doing wrong would be most appreciated.

  2. #2
    Polygon Polygon @Polygonāš–šŸŒ¶

    Well when it's multi-coloured try multiple passes instead for instance.

  3. #3
    MaxHugen MaxHugen @MaxHugen

    Thanks, there are a couple of colours, so tried the multiple scans (8), didn't help.

    I've attached the img I used if that's any help?

    Foil Geometry
  4. #4
    Tyler Durden Tyler Durden @TylerDurdenāš–

    I'd be inclined to hand trace that image. It will give better results.

    Looks more like a CAD job...Ā What kind of work will be done on this?

  5. #5
    Polygon Polygon @Polygonāš–šŸŒ¶

    I'd expect the source is already kind of vector based. Maybe you can request a vector based fileĀ instead of a screenshot or raster image?

  6. #6
    MaxHugen MaxHugen @MaxHugen
    *

    I got this image using the Windows 10 Snipping Tool, from a pdf on the AC75 Class Rules for the next America's Cup race. Saved it as a png file.Ā  It's a wild yacht design by the Kiwis, who won the Cup last time, of a monohull yacht with canting foils.

    It shows a cross section of the yacht hull (purple) and the defined area that a [hydro]foil must be within - ie the shaded area.

    I was hoping to use that shaded design "box" as a sort of template, and rotate it anticlockwise until the bottom of the box is horizontal, and then play around with various foil shapes within that box.

    I'm a complete amateur at both design... and using a drawing program. Just interested in design, as a hobby.

  7. #7
    Xav Xav @XavšŸ‘¹

    A common cause of confusion with Trace Bitmap is that the traced version is placed directly on top of the bitmap, which can sometimes obscure the fact that something has happened.

    After tracing check the status bar at the bottom of the window before you do anything else. If it says 'Path xxxx node in Layer...' then the trace has completed and the resultant path is placed on top of the bitmap. If, on the other hand, it says 'Image ...' then the trace has not happened and your problem lies elsewhere.

  8. #8
    Polygon Polygon @Polygonāš–šŸŒ¶

    ... and I'd try to load that certain page from the PDF into Inkscape to check if there's any vector data maintained. If so there's no need to autotrace, just some cleaning up.

  9. #9
    MaxHugen MaxHugen @MaxHugen

    Thanks Xaz, you're right, I watched the status bar, and as you said, it is there. 😊

    It's a "Path", so I need to do some reading and find out what that is, and probably what "layers" are as well. I think I have to "break it apart"...but I'll read up first.

    Thank you to all for your help!

  10. #10
    Tyler Durden Tyler Durden @TylerDurdenāš–
    *

    As PP notes the diagram already exists in vector format within the PDF.

    To make life easier, I've done some of the grunt-work to get closer to the fun stuff:

    Opened the page in Inkscape

    • Used the Deep Ungroup extension to extract the vectors from a bazillion groups made by the pdf
    • Used select-same stroke color to remove the 101 hash-shading objects
    • Combined the magenta outline vectors of the shaded region into a closed path and filled with wavy pattern
    • Saved as Inkscape svg.

    There are still all the dimensions and extra bits to delete orĀ hide on other layers. Plenty of learning there, in fiddly work and tedium.

    Chime back if you get stuck. :)

    Ā 

    Foil Geometry
  11. #11
    MaxHugen MaxHugen @MaxHugen
    *

    Many thanks Tyler!Ā  It's awesome.

    Looks like I have a bit of homework to do. :)Ā Ā  Still, I taught myself programming decades ago - with assistance from a very helpful forum, so why not!

    One question, how did you open one "page" from a pdf with heaps of pages?

    Cheers.

  12. #12
    Tyler Durden Tyler Durden @TylerDurdenāš–
    *

    When opening a pdf in Inkscape, the import dialog offers choice of page.

    Ā 

  13. #13
    MaxHugen MaxHugen @MaxHugen
    šŸ‘

    Thanks.

  14. #14
    MaxHugen MaxHugen @MaxHugen

    Hi Tyler, in the svg you kindly provided me with, I made a copy of the foil area (with the wavy fill) on the same page, but when I tried to copy it to a new document, it wouldn't paste!

    While following some tutorials, I've made objects in one doc, and I could copy and paste those without issue to my new document.

    Could you advise me what I'm missing pls?

  15. #15
    Tyler Durden Tyler Durden @TylerDurdenāš–

    Ah... my bad. The object is still clipped. I'd use Menu: Object>Clip>Release before other operations.

    Chime back if there are other issues.

  16. #16
    MaxHugen MaxHugen @MaxHugen

    When I did Object>Clip>Release on that object, a large black rectangle covered everything... maybe the area of the original pdf...

  17. #17
    Tyler Durden Tyler Durden @TylerDurdenāš–

    Yes. The black rectangle can be deleted. (de-select all before selecting and deleting the rectangle.)

  18. #18
    Tyler Durden Tyler Durden @TylerDurdenāš–

    Pdf files can have all manner of groups, clips and masks that can be discarded to get at the vectors.

  19. #19
    MaxHugen MaxHugen @MaxHugen
    šŸ‘

    Great, that did the trick!Ā  Thanks Tyler.