A few other potential issues: Path directions can change, eg flip a component horizontally Rounding can become an issue, especially if going small or thin Subsetting is a potential issue, depending on the method Also worth knowing that any component with a transformation (scale, rotate, flip, skew, etc) is automatically decomposed when the font is generated.

Thank you Frederik, your script help me find the culprits easily. After fixing those 3 glyphs in the master, the interpolated instances generate successfully. Solved!

Nice - the code will be super helpful and that's so good to know about the settings. Thank you very much!

here’s a different approach using representations to cache the interpolated glyphs — this may help in terms of performance…

Thank you for the responses. I wondered if yellow was simply advisory, but happy to have confirmation. Much appreciated. Cheers

There is also an update for DesignSpaceEditor, v1.9.2 available from Mechanic2.

Awesome thank you so much!

Thanks for weighing in! Just to be clear, I'm not necessarily expecting things to stay magically compatible – I only am looking for a way to remove overlaps, but leave any points intact that are on the exterior of that combined shape. I think you understood my meaning already, but my initial image was pretty ambiguous, so this shows my general hope better: So, it sounds like the way the Remove Overlap functionality works, it's not that these points are removed as an extra step, but rather that their removal is a core part of the function? And there's no way to "turn that off"? As a simple temporary solution, I have found that I can at least have a visual of missing points by duplicating the glyph to an "overlap" layer, then turning that layer's visibility on. You could run a pre-overlap code getting points that are going to be removed... and add them back in a post-overlap script Is there some kind of accessible list of points to be removed (that doesn't seem very likely), or would I have to find a way to loop through points, and mathematically determine if they're on a straight path?

Ah cool. Thank you!

there is a big difference between being compatible for interpolation (aka fontMath) and for variable fonts. Variable fonts requires (out of my head): same amount of point both oncurves as offcurves same amount of kerning pairs same amount of kerning groups same amount of glyphs

Here's a small script that guesses the weight value of UFOs and tries to make a designspace for them. Lots of dowsing and talking to spirits, but maybe useful for some projects. https://github.com/LettError/makeDesignSpace

thank you!

This seems to fix my problem, thanks so much! One more thing, what would be the name of the observer for if a glyph is modified?—so that I can update the preview as you make changes. Is there a list somewhere of all the built in observers? Cheers!

He Ben If you have a python package installed in the current python on your local machine, that package will be accessible in RoboFont. RoboFont is adding the site-packages of the current python to the sys.path. So if you have a python package that can read from a serial port it must be possible to access that package in RoboFont good luck!