I filled out their support form 2 weeks ago and received no response. Maybe their form is broken, so I’ll ask here.
I was doing some experimentation with engraving slate coasters. I engraved using this SVG
But where lines crossed it would not engrave yet it looks fine in inkscape and the UI. Any ideas?
There is a known issue where overlapping/duplicated lines don’t cut or engrave. This looks like a variant of that. I think the general “best practice” (and what I do in most cases) is to export graphics to be engraved to PNG first.
Thank you. Sorry to ask, is there a repository for all “known issues”?
Looks to me like the same thing that happens when text letters don’t get ‘welded’ or joined…which happens most often in a cursive text. I don’t use Inkscape, but there must be some way to do that with this design.
Those aren’t “lines”, they are filled shapes. They appear to form a complete shape because they are the same color, but the actual object the GF sees looks like this:
Because the vector engrave function only supports the “even/odd” non-zero process (edited, thanks tim), it will flip from engrave to ignore as the beam crosses each object’s perimeter, resulting in the un-engraved area you have seen.
You need to merge (Path/Union) the individual elements to form one solid path. Like this (I got bored so only this portion is done, but you can duplicate, flip horizontal, then Union the two halves…)
Or just convert to bitmap and engrave that, but I prefer to do it “right”…
This forum is pretty much it. It is not explicitly organized for that, but you can often find the relevant information with a search or two. For instance, searching on “overlapping lines,” I see that some of the posts in the first screen of results talk about this:
https://community.glowforge.com/search?q=Overlapping%20lines
If you post a problem that is caused by a known issue here, you will generally get a reply from a Regular about it.
There is also a sort of F.A.Q. maintained by one of the community members:
Wouldn’t control/cmd-a, path->union have done it?
You would think so, but something about that design prevented it. It didn’t matter enough to me to figure out why.
I think this one will do what you want.
Then again, maybe not. Something is weird here too. Sorry.
Thanks, I’m more interested now in learning more about this comment and understanding this even/odd process. Is it documented anywhere?
:
Because the vector engrave function uses an “even/odd” process, it will flip from engrave to ignore as the beam crosses each object’s perimeter, resulting in the un-engraved area you have seen.
It’s not officially documented, but was observed here from the beginning and discussed frequently.
It’s also often the reason objects don’t engrave at all - a duplicate of the same object is stacked on another, so that area is simply ignored.
Most vector formats (including both SVG and PDF) support two different rules for how to fill an object, the even-odd rule and the nonzero rule. Here’s a description of how the fill rules work: Understanding the SVG fill-rule Property — SitePoint
The Glowforge software only supports the nonzero rule in SVG files. In PDF files it supports both rules (even-odd and nonzero) so you may be able to fix your problem by converting the file to PDF before uploading it.
I first discovered this bug back in 2017. I used to report it annually but I gave up after a few years. Here’s one of our past discussions on the topic: Glowforge still doesn't support the even-odd fill rule in SVG files as of January 2020
My rule of thumb is to never do vector engraves. You can either learn all of the bugs and workarounds, or just rasterize. There’s a trick in Illustrator at least where if you apply a rasterize effect, it remains fully editable but gets rasterized on output, so it’s kind of the best of both worlds. (I made a video to demonstrate this a few years back)
