I have a question about the SVG format. My understanding is that there is a pixel/inch resolution setting and different programs export in different resolutions. For instance Inkscape uses 90 px/in and illustrator uses 72 px/in. What resolution is used with LibreCad?
I'm using a cam program, makercam, to generate tool pathing for a CNC so in order to make cuts at the correct dimensions it needs to know what the resolution is.
"My understanding is that there is a pixel/inch resolution setting and different programs export in different resolutions."
My understanding of SVG is that it has no resolution cause you can scale it up like you want.
So I don't know if there is a "SVG Export" resolution.
"For instance Inkscape uses 90 px/in and illustrator uses 72 px/in. "
You can use the exported SVG (from LibreCAD) and open it in Inkscape.
This way you can use the resolution you told.(as you are talking about "SVG Export" I gues you are already using LibreCAD 2.0.0, cause I don't know if the 1.0.3 version does have a svg export option)
As you can see in the export dialog, you can choose a resolution. This resolution is multiplied with size of parts to export. For none-vector formats the image gets this calculated size. When you export a SVG image the size is set to the original size.
So I think you could understand the resolution set in the dialog as the resolution per choosen unit (normally millimeters).
@cantcode: Your right. I added the svg export about one year ago and it was released as part of version 2.0.0.
If I create a 100x100mm square in LibreCAD and export as an SVG what resolution should it be set to? If I try "auto" and open it in FreeCAD it measures 102.305mm. If I try resolution "1" FreeCAD shows 31.750mm. Inkscape seems to show roughly the same numbers as FreeCAD, I'm just not as familiar with it as FreeCAD. Also changing the border seems to change the size of the square. And after trying different resolutions now when I go back to auto it's showing up as 31.711mm in FreeCAD.
"Inkscape seems to show roughly the same numbers as FreeCAD..."
That's strange. When I draw a 100mm x100mm square and set the resolution to auto and the borders to 0,
I get a "35,631mm" rectangle.
When I do (in Inkscape) Path->Object to Path, the length of the upper line is "35,278mm" (the thickness of the line/cap is not included here).
Can you please tell, what version of LibreCAD 2.0.0 you are using (rc1,rc2, beta,...)?
And what operating system you are using (also if 32/64bit).
A simple workaround is to open the exported svg file and set the width/height (should be the second line of the file) to the size you want. But you should take the thickness of the line/cap into acount.
<svg width="35.2778mm" height="35.2778mm"
I opened the file and set it to <svg width="100mm" height="100mm" and now FreeCAD shows the correct measurements. It may be a simple workaround to fix a 100x100 box, but what do I do with more complex files that have different shapes of different sizes.
"...but what do I do with more complex files that have different shapes of different sizes."
The same. :)
You have to remember the width/height from the export window in LibreCAD(resolution should be 1 or auto and the borders 0) and change the values in the svg file to the values you remembered.