Hi,
I am new to seamly2d and created a draft block pattern piece for the front without seam allowance and it worked out fine. I followed the same process for the back bodice and when I removed the seam allowance the entire block was filled with grey dots. I was unable to identify the issues since I followed all the steps like going clockwise, non-overlapping nodes etc. Will appreciate if you could guide me. I am attaching screenshots for reference.
In Piece working space click on the piece with dots and check properties or press “P”
Go to “Paths” tab
Now check the “main path”
Such piece often happened if the hole piece is inside out, maybe they are also other reasons
Thank you for sharing feedback! To the best of my understanding, I have gone through all of those steps and couldn’t pinpoint the issue. Including a screenshot of the main path tab in pattern piece with seam allowance included. One of the only thing I can think of is that I moved the location of the A9 and A32 node after the back bodice was drafted when I spotted an error. I then connected A9 to A34 and A35. I still followed the clockwise selection but not sure if that has an impact on my current issue?
Welcome to Seamly!
Sometimes moving the last object in the path to the front will fix things like that. More often a curve handle is pointing in a wrong direction.
If you post the pattern & measurement files, one of us will be happy to give it a gander.
Please post your pattern and any measurement file and we can fix the patttern.
There is either an issue with the main path, a curve in the wrong direction, or with incorrect control handles in a curve. The path has to be continuous in a clockwise direction or the SA get’s mixed up.
Hi Douglas and Pneumarian,
I am uploading the two files used to create the individual pattern. Thank you for your help!
Base38_ABCup_FitA-StraightBodice.sm2d (29.5 KB)
Base38_ABCup_FitA-StraightMeasurements.smis (728 Bytes)
So the issue is that I do not want the seam allowance included. When I exclude the seam allowance, the back bodice is filled with grey dots. The same thing doesn’t happen with the front bodice piece.
Open the pattern piece properties and change the default seam allowance to 0.00001 to exclude the seam allowance:
Or remove the checkmark at “Show cut line”. This way, you can leave the seam allowances at their original settings and just toggle the cut line on & off depending whether you want to see the cut line or not:
I hope this helps you.
Thank you so much Grace! The 0.00001 works for me but still the dart legs of A55 A54 and A56 gets covered in grey dots.
For the show cut lines, if I turn it off dart A55, A54, A56 doesn’t show the dart lines. Am I doing something wrong? It appears like those dart legs could be the issue.
I got the same results in either case… on Windows.
@neytiri19 - What OS are you using? I need to know as there has been a similar issue report when using the macOS. version.
That is interesting..I am using Mac Tahoe 26.2. I even have issues getting the notches in, sometimes it works and sometimes it refuses to show up.
Yeah… someone else reported a similar issue when using a “0” default SA. The fact that using something like .00001 fixes the issue leads me to believe it’s a floating point fuzzy math issue. It’s probably related to how the M chips handle the floating point math differently than the x86 chips. I also have a macBook with an M3 and it displayed the same issue the other user had. I will try your pattern later and see if I get the same result as you. I will also look into if there is something I can fix with the SA routines which I suspect are using some fizzy math routines.
Thank you for looking into this, Douglas! The issues come up in the Piece section for both SA and/or adding notches. It randomly throws off the nodes path. Atleast, appears random to me.
It’s random because of the geometry. Sometimes even changing the size in a multi-size pattern can throw the SA off. The SA and notches are all based on extending lines and finding intersections. Think of putting in golf… where if the hole was the size of the ball… you would have to dead on (equal to zero) to sink the ball, where as with a larger hole you don’t have to be as accurate (.00001 works). The issue with the mac is like I said probably related to the hardware. It could also be related to Qt changing how it handles floating point math with later versions of Qt 6. There’s been a bunch of issues that popped up when we switched to Qt 6.8 that were not there in Qt 6.5. Which is probably something else I could check on the mac.
Hmmm… Just remember that using 0.00001 still is a milli-fraction of a unit, so there is still a seam allowance. By using the Built-In option, it shouldn’t have any seam allowance or a negative seam allowance of the value. The grey dots between the dart legs could be that the dart legs are too close together, as well.
However, if you don’t want to see the ‘grey dots’, you can change the settings of the pattern piece to give it a Solid, White fill:
I’ve dragged it over the front piece so that you can see that it’s no longer without colour.
This is what it would look like without the fill:
I did a deep dive into the issue… and there are several overlapping issues.
and one I suspected as an issue 4) Pattern units… metric units (cm & mm) have an error rate 25.4% higher than inches. Inches convert to pixels (DPI) with no noise while cm create noise converting to DPI.
All these can manifest many of the random issues that pop up in the SA. In my investigatgion I have ideas to fix and quard against many of these edge cases.
