Extra nodes are being added somehow

Inkscape related questions, tips and topics can be posted here
Post Reply
Bigdogbro1
2.5 Star Member
2.5 Star Member
Posts: 101
Joined: Tue Aug 18, 2015 9:20 am

Extra nodes are being added somehow

Post by Bigdogbro1 »

Just recently I have a problem with either Inkscape or Sheetcam where I create a file in Inkscape such as an oval using the oval tool with only three or four nodes and a curved cut line. When I import the file into Sheetcam the oval has many more nodes and the cut line is no longer curved but instead many straight lines connecting the 50+ additional nodes. Letters seem to not be affected. The piece cuts this way as well. The file is .svg.

What has changed in Inscape or Sheetcam to cause this?

Thanks
User avatar
acourtjester
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 7796
Joined: Sat Jun 02, 2012 6:04 pm
Location: Pensacola, Fla

Re: Extra nodes are being added somehow

Post by acourtjester »

Have you tried to use the simplify command under the path tab.
Just select the path you want to change and click on simplify, if you don't like the change just click on edit and click on undo and its back to the original path.
DIY 4X4 Plasma/Router Table
Hypertherm PM65 Machine Torch
Drag Knife and Scribe
Miller Mig welder
13" metal lathe
Small Mill
Everlast PowerTig 255 EXT
Bigdogbro1
2.5 Star Member
2.5 Star Member
Posts: 101
Joined: Tue Aug 18, 2015 9:20 am

Re: Extra nodes are being added somehow

Post by Bigdogbro1 »

Thanks, but the simplify command not only simplifies and reduces the amount of nodes on the line but it also changes the shape.

I want to hear the reason why all these extra NODES and straight line segments are now being added by one of these programs.

Besides...this issue just recently manifested and not sure what is causing it. All was fine a week ago with curved line files being generated in Inkscape and imported into Sheetcam.
Bigdogbro1
2.5 Star Member
2.5 Star Member
Posts: 101
Joined: Tue Aug 18, 2015 9:20 am

Re: Extra nodes are being added somehow

Post by Bigdogbro1 »

From what I have been reading it seems to be a BUG in Inkscape.
User avatar
WyoGreen
4 Star Member
4 Star Member
Posts: 897
Joined: Tue Mar 04, 2014 8:36 pm
Location: Cheyenne, Wyoming

Re: Extra nodes are being added somehow

Post by WyoGreen »

I have found that different versions of (AutoCad)DXF file saving can cause the extra nodes/straight line segments problem. CorelDraw gives you the choice of saving as a DXF anywhere from AutoCad version 2.5 thru AutoCAD 2008-2013. Some versions save the lines as splines, some as polylines, some are nice and round, some are the segmented lines you mention. I don't know if Inkscape gives you the choice, but might be worth checking into.

Steve
Precision Plasma gantry
CommandCNC Linux controller w/Feather Touch & PN200 hand controller
HT-45 plasma cutter
Plate Marker
Router
Laser
Chris Linetty
1 Star Member
1 Star Member
Posts: 21
Joined: Fri Mar 04, 2016 2:01 pm

Re: Extra nodes are being added somehow

Post by Chris Linetty »

I'm having the same issues. Scaling is all jacked up too! Frustrating!
Arc Light 48x96
Hypertherm 45a
Inkscape, sheet cam, Mach3
New as crap on this stuff, but having a blast!!! :D
User avatar
acourtjester
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 7796
Joined: Sat Jun 02, 2012 6:04 pm
Location: Pensacola, Fla

Re: Extra nodes are being added somehow

Post by acourtjester »

I'm not sure if this will help I set inkscape to have inch scale and then when I save it with SVG and open that in SheetCam I change scale 1 to 1 and it is correct. I see that SheetCam normally opens a SVG in like 1 to 25 scale which is really big way oversize for the display.
DIY 4X4 Plasma/Router Table
Hypertherm PM65 Machine Torch
Drag Knife and Scribe
Miller Mig welder
13" metal lathe
Small Mill
Everlast PowerTig 255 EXT
User avatar
Capstone
4 Star Member
4 Star Member
Posts: 1015
Joined: Fri Sep 13, 2013 8:42 am
Location: Washington D.C. Metro
Contact:

Re: Extra nodes are being added somehow

Post by Capstone »

Inkscape to SheetCAM scaling is definitely supposed to be 1:1 for all SVG files.

Anyone who's used to DXF, you will just have to remember that fact when bringing in .svg.

My scaling results going all the way from page to final cuts (provided you have accurate kerf settings) has been reliably dead-on to the point that I trust my measurements shown in Inkscape over what the customer may have called out on drawings. Just yesterday I was copying some drawing on some gauge panels and the scaling clearly showed where the customer had written down the wrong measurements. He was really happy that I caught this during my conversion and the final results were within 1mil on the critical gauge openings.

As for the extra nodes, I too see this, especially after I use the "union" command a lot while putting together personalized pieces with names etc. I think that, and I'm no coding expert, Inkscape is the culprit, leaving 2 nodes for every intersection of a weld point in the design. It's a really big problem when going from a dxf file already created to Inkscape. There are dozens of threads here talking about the "hundreds of nodes" problem in SheetCAM on certain drawings that start out as large dxf files.

My "fix" has been to select small portions of the design nodes and either re-combine or use the "join selected nodes with a new segment" command and then using Union again until the double nodes are eliminated.
Phil
It's all relative...
CNC Metal Design
Instagram CNC Metal Design
JD Squared 4x8
HT PM45, Miller 251 MIG
Post Reply

Return to “Inkscape”