Is there a pressure sensitive powerstroke?

[HeroicNate]

Hi,
Long time admirer, first time poster. I've really been digging into Inkscape and am starting to love it. I especially enjoy the powerstroke feature but what I haven't been able to find out is if I can tie the powerstroke to my pen's pressure. Is it possible to draw a freehand stroke that records my pen pressure into a power stroke?

I've found that the calligraphy/brush tool works nicely with pressure but if I need to adjust the a curve I might as well just redraw the line. I also end up running a simplify on almost every brush stroke as it adds a lot of seemingly unnecessary points. I say unnecessary because the simplified version looks virtually identical.

Essentially what I'm hoping to find is something that combines all of these things. Free hand stroke + pressure sensitive brush + simplification + powerstroke. So it is like the Calligraphy brush style pressure records and simplifies the powerstroke that is applied to the free hand drawn stroke. Is that a thing?

THanks for the amazing program!
 

[brynn]

Welcome to the forum!

I don't think it's possible to combine all of those.  Because it doesn't work to apply the powerstroke to a closed path, which is what a Calligraphic line is - a closed path.  I'm not sure if that's a bug or not.

If you use the Pencil tool, with the Triangle In or Out shape applied, the Powerstroke LPE is automatically applied.  And plus, new with 0.92 (or might have been 0.91) there's an option to automatically apply the Simplify LPE (which is a live version of the regular Simplify).  So that gives you 3 out of 4.  Except that you might not necessarily what the triangle shapes.

If you draw just a simple path, with Pen or Pencil (with no shape added), you can apply the Pattern Along Path LPE (PAP can work like Calligraphy, in a way), Powerstroke, and Simplify LPE.  That gets you 3 out of 4 too, and you choose your own shape (the pattern of PAP).

The problem is that only the Calligraphy tool can provide pressure sensitivity.  I suppose if it were possible to make the Pencil tool have pressure sensitivity, you'd have it all at once, without the conflict between Calligraphy and Powerstroke.

I don't know how that would go over as a feature request.  But I don't see why it wouldn't work.  I mean, that's been a complaint from the very beginning about the Calligraphy tool, is the excessive nodes it creates.  I wonder why it was chosen for pressure sensitivity, over the Pencil, in the first place?  (Actually the Pencil tool can create oodles of nodes as well.)  Maybe because that was the only way to get a variable width?  But now that we have the powerstroke.....

Well, I'm not a programmer.  But if Calligraphy was chosen for pressure sensitivity, because is can create the variable width.  And if we now have powerstroke, which can create variable width for the Pencil or Pen.....  Well, I don't see why not make the Pencil available for pressure sensitivity, and use powerstroke to create the variable width.  Like for example, place a pink node where the pressure is greater, maybe??

Since Inkscape is open source, anyone can make a feature request, you're certainly welcome to do so.  Now you've got me so curious, I think I'll ask on the mailing list whether it would even be possible.  I'll let you know what they say.

[HeroicNate]

Cool! There's definitely ways to achieve desired looks. The caligraphy tool, pattern along path, and powerstroke are pretty great on their own. It would just be great for pencil to have a pressure sensitive powerstroke like we're talking about. So something like the below screenshot.



Then you could possibly even change the powerstroke "width" by altering all of the points relative distance. That way you could retain the pressure sensitivity information but also have a modifiable curve and stroke width. I still need to investigate if there's a way to adjust pressure curves, but the current support works pretty well.

[brynn]

Well, there's more good news!  The developer who has created all the LPEs (as far as I know) answered my message, and said it should be fairly easy to do, to give pressure sensitivity to the Pencil tool using powerstroke.  However, he's asking questions that I can't answer, since I don't use this kind of feature.

Would you like to subscribe to the mailing list, so that you can discuss it directly?  Here, you can read the archives without subscribing:  https://sourceforge.net/p/inkscape/mailman/message/36005048/.  But I'm pretty sure you'll need to subscribe, to be able to post a message.  https://inkscape.org/en/community/mailing-lists/  It's the Devel list that you want.

[HeroicNate]

Cool I will subscribe!

[HeroicNate]

Tonight I'll send a message after I can get some examples together. I have ideas around the preview in that it could use the calligraphy style just for preview purposes, even if it actually just discards that info. I'm going to put something together when I get to my own system.