Problem with interpolating sidebearings and ‘Spacebar’ plugin


Sometimes I’m getting weird results when I choose ‘reinterpolate metrics’ and even weirder results from the ‘Spacebar’ plugin (trial).

I’m working on a Glyphs-file with one axis (weight) and three masters: 100 - 500 - 999 (light - normal - black). No brace or bracket layers.
For one glyph I set the right sidebearing for both light and black at 70 units. Then, when I choose ‘reinterpolate metrics’ for the normal weight the value is set at 89(!), while it should of course be 70 as well…

To make things even stranger the Spacebar plugin from @yanone shows this rather funny graph of all the interpolated sidebearings.


And here’s another example that’s even funnier.


Is this a Glyphs ‘thing’ or a Spacebar thing? Or am I doing something wrong?


Hi there. Thanks for the notification. I’m on vacation for another week now and will have a look at this once I’m back. I will need your glyphs file for this. If you could please mail it to post at yanone point de ? If the behavious shows up across all glyphs, you can delete all but one glyph, if you want. Thanks for your help.