Problems with inexact dragging of nodes locks Inkscape up.

[fantomx11]

Many times, when I am trying to drag a node, I will accidentally click on the path and drag it. It tries to move the path instead of the node, which usually works fine, but when I grab it so close to the node (because I was actually trying to grab the node itself) it almost always locks Inkscape up as it tries to adjust the path to incredible lengths. Unfortunately, I am unable to replicate this intentionally, but Inkscape locks up almost every time I accidentally grab the path right beside a node. Is there any way I can make the nodes bigger or disable grabbing the path?

[brynn]

Welcome to the forum!

Yes, that happens to me a lot too.  Unless your file is very large, or you're working at high zoom, it shouldn't lock Inkscape up.  But I guess the secret is just to try and be careful about grabbing the node.

There is a setting to make the nodes larger.  But personally, that tends to annoys me more than the difficulty grabbing the smaller nodes.  But if you want to try it, it's Inkscape Preferences > Input/Output > Handle Size.  And possibly the mouse sensitivity settings there could help you (the smaller number, the closer you have to be, to grab it).

This often happens to me when I'm just trying to select nodes, instead of grab and drag them.  For that, you can drag a selection box around the node (or nodes) instead of clicking on them.

Other than that, I guess it's just slow down a little and be careful.

I can say that this problem only started for me sometime in the last couple of new versions of Inkscape.  I wouldn't know exactly what changed that causes this, but it IS annoying.

[Moini]

That bug has been fixed, as far as I know. Update to 0.92.3 (http://wiki.inkscape.org/wiki/index.php/Release_notes/0.92.3#Important_bugfixes)

[brynn]

Hhmm, I'm not sure if it has actually been fixed.  It just happened to me the other day, and I'm using 0.92.3.  But I'll pay more attention next time, so I can report if it happens again.

Edit
Oh I see.  They fixed the crash part, but apparently not the tiny movement making the huge path.  Seems odd not to fix the whole problem, but I'm certainly no expert.

[Moini]

I'm not sure how that can be fixed - people may actually want to grab the path in that place. Any suggestions?

[brynn]

For me, the problem is that a tiny movement of the mouse extends the handle of the node by sometimes a couple of whole screens -- way, way, way off the visible part of the screen.  Yet I only moved the mouse by an eighth or quarter of an inch!  I was trying to click the node, but being in a hurry, I clicked too soon, so that the mouse was still moving when the click happened, and it dragged the path by the tiny amount which I missed the node by.  But the handle went off into space!

I would have assumed that exponential movement was causing the crash.  But it sounds like they just somehow blocked it from crashing, but still allow the exponential movement of the path.  To be honest, when it happened to me the other day, the handle didn't go as far as before.  It still went off the screen, but only by a little, instead of by 2 or more screens away.  So maybe they partly fixed it.  But still, the mouse only moved a tiny bit, compared to where the path went.

I've never actually had a crash when this happens.

I'm not sure....I don't think I knew that there was a bug report for this, or else I would have posted a comment.  But I'll watch for the next time it happens, and make a report if I need to.

[brynn]

Ok, it just happened again.  The mouse moved at most a quarter of an inch after I clicked prematurely.  The path itself became about 2 inches longer (well, it developed an elongated loop actually), and the handle went off the visible screen, to become approx 5 inches long.  There was no handle before, since it was an end node, in this case.

So not as extreme as 2 or 3 screens long.  But to me, that still seems like inappropriate behavior.  If I drag a path by a quarter of an inch, I think I should expect it to move somewhere in the neighborhood of a quarter of an inch.  I wouldn't even complain if it moved a half inch.  But 2 inches is 8 times the dragged distance.

Since that bug is marked as Fix Released, should I go ahead and post another comment to it?  Or should I make a new report and link to it?

Like fantomx 11, I would find it hard to capture it in a video, since it happens by accident.

Hey, is there some acceleration feature for the mouse in Inkscape, which I could opt out of?  An acceleration feature would explain this, but I wasn't aware Inkscape had something like that. 

I think my mouse has some acceleration, but I wonder why it only seems to happen in this situation.  I mean in Inkscape.  If Inkscape were using ( by design or not) the acceleration from my mouse, I wonder why it doesn't happen every time I use the mouse, and not only in this situation?  As hard as I try, I can't make it happen on purpose.  The only thing I can see that affects it, is the closer I am to the node, the worse the exaggeration is.  If I grab halfway between 2 nodes, the path behaves as expected.  It's just close to the node where this happens.

Oh, I think I can reproduce it!  Very close to the node, and also, the direction is important.  If the drag goes in the direction of the path, the exaggeration is maximized.  If the drag is perpendicular, there is no exaggeration.  I'll make a vid for the report.  I'm just not sure whether to make a new one or not.  Or should I show the video before I make a report, in case this is somehow expected behavior?

Edit
Oh, the speed of the drag matters a lot too.  If I drag very slowly, I get very appropriate behavior.  But if I drag it fast, like a jerk (I mean a jerking motion, not like acting like a jerk ), which is exactly what happens when you're in a hurry and miss the node - the faster I drag, the longer it gets!

[fantomx11]

The amount each of the handles move when you grab a path is related to how close to each node you grabbed the path. I assumed that the extreme movement is because I am only one or two screen pixels off of hitting the node in the first place, so where I grabbed the path is very close to that extreme. Likewise, the difficulty in duplicating it is because at such small increments, it does not take much to be out of the extreme zone (not knowing the math of how splines work, but it would seem being 4 pixels way from the node instead of 1 would lead to the handle only moving 25% for the same mouse movement).

Also, I have upgraded to 0.92.3 so hopefully that will at least keep it from crashing on me.

[brynn]

"Splines"?  I guess I've heard some people refer to vector curves or paths as splines.    But if you're using the Pen (or Pencil) tool in Spiro Spline mode, that could really, really exaggerate the already exaggerated effect!  There's a nice big bug with spiro spline mode, which would explain the extreme behavior here. 

(I haven't tested this in spiro spline mode.)

[fantomx11]

Spline is just another term for bezier curve, which is what all vector curves in Inkscape are. Spiro Spline makes a more circular curve (the spiro part) out of the existing curves, but all of them are still splines.

[Lazur]

Spline is the general term. Coming from the drafting past where they used steel rods&wood strips to lay down courves on paper.
spline in action.

Bézier splines are just one of the regular ones.
Bézier splines

Inkscape's basic paths are cubic splines. However there are the options to use spiro and B-spline too.
Latter being closer to NURBS which was meant to be used in cad softwares.
But those two are achieved by path effects, the core is still about Béziers -performing some Boolean operations converts them to regular paths suggests so. Although NURBS theoretically could retain their structure way better.

[brynn]

Thanks for the info.  I tried to read and understand, but it's mostly over my head.  But I will remember that it's reasonable to call them splines.

I just wanted to clarify if this behavior is seen using spiro-spline or b-spline mode features, that could (potentially) make the problem even worse.