Variable font won't export due to TrueType curves

I was previously able to export my file with a single weight axes, but after adding a width axes, I’m receiving the following error:

Can't convert to compatible TrueType curves.
Glyph "Aacute" is not compatible.

If I turn of export of that character it will seemingly randomly pick another character and give me the same error. All characters interpolate successfully across all weights and widths when exported as OTF or TTF files. I’m not seeing anything abnormal between masters and I’m not getting master incompatibility errors anywhere.

Currently running 2.4.3 (1064) on macOS 10.12.6 (16G29).


Can you send me the .glyphs file? And what version do you have?

Try the latest cutting edge.

In non-OTVar setups, TT conversion happens after interpolation. With OTVar, it is the TT outlines that need to be compatible. Very often the culprit is an inflecting curve.

It stops when it meets the first TT incompatibility. There can be many in the file, of course.

Currently running 2.4.3 (1064) on macOS 10.12.6 (16G29).

Where should I send the .glyphs file to?

And I’ll install 2.5 and see what happens.

Just gave it a try in 2.5 and getting the same error.

There are a lot incompatibilities. In ‘G’, the first master has different path direction and in ‘Odotbelow’ the order of the components are wrong (again in the first master).

There is a bug in the code that checks the compatibility if an ‘Axes’ parameter is present. So temporarily disable (rename it to ‘Axes_’ it and reopen the file. Then you will get the red bars in a lot glyphs.

I fixed the problem.

And you might need to have the same set of masters in both condensed and extended.

I tried with a copy of the file where I cleared everything except the 3 matching sets of condensed/extended masters and I was still getting the same error, so I assume it’s due to the incompatibilities in individual glyphs.

Removing the Axis parameter didn’t help, and although I’m still getting the TT export error, I’m not seeing any red triangles, only seeing red bars inside individual glyphs. Can’t figure out what the issues. And this has now shifted to figuring out interpolation issues on a glyph and not an app bug with variable fonts, so I’ll be quiet on this thread for now.

Thanks for the help.

The red triangles appear in Font view, the red bars in Edit view, but they indicate the same thing: incompatibility of interpolating paths. Please read the Multiple Masters chapter in the handbook, and the Multiple Masters tutorials. Both also explain how to fix incompatibilities.

I uploaded a new versions that will correctly flag the incompatible glyphs.