Using B-splines to draw italics

ivan louette

I am just curious : does some of you use B-splines to draw italics ? And which type drawing program propose it as a step in drawing ?

I just ask it because at the moment I am stunned by the ease they offer to draw the more organic shapes suited to italics.

Here is an example of what they can do in Inkscape, which remains my main drawing program. I don't show it to ask critics on this shape which is a very early and rough step, but to illustrate this interesting technique.

Peter Baker

I spent much of the morning playing with Inkscape because of this post, and I agree that B-splines are amazing, and not only for italics. I'm not sure they're better than spiros, but both aim to solve the problem of it being difficult to create (as opposed to edit) outlines with the usual cubic splines, and they work very well. Inkscape also converts very cleanly to cubic, and if you save as "plain SVG," that can be reliably imported into FontForge.

Glyphs has trouble importing some of those SVGs, but they can be opened in Illustrator and then copied and pasted into Glyphs. (I suppose that FontForge could also export something that Glyphs could open.) Sounds awkward, but not a lot of trouble actually.

As to whether other apps use B-splines, I haven't found any. The Illustrator "Curvature Tool" produces what looks to me a lot like spiros.

Anyway, thanks for mentioning this. It's very good to know.

ivan louette

@Peter Baker I am glad it was useful for you ! On my side I work on Linux (Kubuntu), I copy and paste all my drawings from Inkscape to FontForge. That's quicker than saving to SVG (or even to SVG font) and importing it to FF. And after copied the B-splines are automatically converted to Bézier inside the clipboard, thus you don't have to convert them in Inkscape before. Then you can add extremas in FF, remove some nodes and adjust precisely the curves (that's better if you paste a copy of your drawing on another layer and use it as reference for adjusting after fusioning curves).

Perhaps you could use PDF to transfer your drawings to Glyphs ?

Another program which used B-splines was Creature House Expression. But If I remember well you can not manage them there so easily. For example in Inkscape you can change curve tension at every node in B-splines : simply Shift-move the handle.

Igor Petrovic

I've just googled "draw b-splines online" in order to see what they are and how they behave. I found this:

http://nurbscalculator.in/

It feels very intuitive and makes nice smooth curves easily. Why don't we have this in font drawing apps?

Peter Baker

It is very intuitive! I updated my old Linux box, had the latest version of Inkscape going very quickly, and found that using B-splines speeded up drawing a good bit. The workflow I've settled on is a _bit_ tedious, but worth it: rough in an outline (it's also very good for tracing) and paste it into FontForge (thanks for the tip about pasting, @ivan louette!). When I've done as much as I want for the day, generate a cff-flavored font, move it over to the Mac, open in Glyphs, and copy the new outlines over to the master file for later refinement.

ivan louette

@Peter Baker In order to work flawlessly with Inkscpape after 0.92 the best is working with 750 pts fonts, which correspond to 1000 UI in FontForge (or you may multiply that).

The only problem I have is when I use my exported fonts in LibreOffice which has a bug (reported some years ago but not solved at the moment) : it slightly moves away vertically start or end node and that create a step in the curve. This problem doesn't occur in Word, InDesign and QuarkXPress. However it disappears while you change the UI of your font in FF. perhaps is that due to my copy and paste process which preserves a zero length segment between start and end nodes (this is apparently a part of  the SVG specification).

ivan louette

@Igor Petrovic That would be nice if type drawings apps had this functionality. As B-splines are part of Bézier curves they are very easy to convert afterwards and add extremas.

WAY KYI

Thank you very much to all of your suggestions. Seem like moving glyphic drawing part to Font App will solve all the problems. Because, it is WYSIWYG ( what you see is what you get ). I will need to start doing it in font app, instead of two apps. Thank & happy New Year everyone.

Franz Gratzer

I had never considered using something other than classic Bézier curves with tangent points yet because I always felt that they offer the most predictable outcomes and best control over curves.

But nice to see that others here are also using FontForge and Inkscape. (Maybe some day I can contribute something useful with those tools. I stick with free software for ethical reasons and I believe in other areas too an open approach to works can be much more beneficial than most people expect. I am glad that CC and the SIL OFL do exist.)

So far I had the impression mostly professional type designers are here. I have been reading here for some time now and only today decided to finally register.

Christian Thalmann

Maybe I should just give it a try and see for myself, but from what I see in screenshots and videos, I don't see the point of b-splines. I can easily create a shape like the one in the OP in Glyphs in short order, and actually decide for myself where the extrema are going to lie (unlike in the image above). The points seem to have very little to do with the resulting curve, and I'm confused as to why the second and third arch should have such different point distributions for what looks like two very similar shapes.