Inkscape 1.xx slow on iMac Catalina OS

OK since I’m a newbie I can ask this question. Why would you need to have the path going clockwise or counterclockwise and why would that matter for the GFUI?

Well I bit the bullet and dropped down the 35 bucks for AD. Since it was 30% off I took it advantage of it. I ended up printing out or cutting out (it should be really called?) an iPhone stand. Below is a pic of the front and back.

I ended up having to scale a second cutting since the first cut was for thinner material. The material I cut was 0.13”. So in AD I had to do a little math and scale up the second cut. I measured with calipers the gap where the two pieces slide together in the original first cut and it was 0.079”. To make the stand work with my 0.13” material I had to scale by a factor of 1.392. The math goes like this:

0.079/0.13 = 0.608 (ratio of thin to thick material)

1 - 0.608 = 0.392, then to scale up from original size to my material thickness it would be 1 + 0.392
= 1.392.

The 1.392 value was then entered into the transform dialogue box in AD to scale up by a factor of 1.392 and voila the correct fit on the second cutting. In AD you enter the equation:

• = 1.392 (for multiplying by the scale factor)

Well kind of a correct fit. It was a tight fit, and I had to force the two pieces together. I have to admit I did not consider the kerf of 0.008 (newbie mistake). And I’m not sure but if someone could chime in. Do you have to multiply that kerf by two since there is two edges of the two pieces coming together?

Here is a pic of the two different sizes with the assembled piece being the larger of course:

Anyway great thread info so far…

The direction of paths only affects which parts of a shape are filled when using the non-zero fill rule (which Glowforge always uses when importing SVGs). It’s part of the definition of the non-zero fill rule. (And of course fills only affect engraving; scores and cuts only look at where the path is, not what’s filled.)

Affinity Designer usually uses the even-odd rule, where direction doesn’t matter. And if you export from AD to PDF format, even-odd works fine and you don’t have to worry about it. The only time it’s a problem is if you use SVG and the Glowforge converts all all your shapes using the even-odd fill rule to use the non-zero rule, at which point the wrong parts of the shape may be filled.

Inkscape/Illustrator users don’t run into this as often because those programs default to non-zero fill so you don’t get any surprises when loading those designs into the Glowforge.

AD users do tend to run into this because AD defaults to using the even-odd fill rule. It’s not a big deal, you just need to do one of three things to fix your files when you run across it:

1. Convert shapes to use the non-zero fill rule and then manually reverse paths as needed to make the correct areas fill. (This is very tedious and I do not suggest you actually do this in most cases!)
2. Export as PDF instead of SVG. (This is the easiest solution and is what I do most often.)
3. Rasterize shapes that you intend to engrave. (But then you have to worry about things like the document resolution. In some cases this may be the best solution, but usually exporting as PDF is going to be easier.)

AD isn’t the only program to make heavy use of the even-odd fill rule. Corel Draw is the same way. But because the people at Glowforge seem to only bother testing their product using files from Illustrator and Inkscape they haven’t shown any interest in fixing the problem with the even-odd fill rule in SVG files.

Thanks for the input tim1724. A lot of great info there.

Since you seem to know quite a bit about GF and vector graphics I’ll ask an unrelated question. On this forum do you happen to know how people reply to to others in this forum with a gray box quoting the other persons reply to reference your own reply. For example your reply to mine:

Thx

Highlight the text you want to quote then click the “Quote” button that appears next to the selected text. Like this:

2 Likes

Maybe a fix;

1 Like

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