Filters in action, filters in pack

[Lazur]

@Brynn: He means it's the most convenient way to laser-burn (or otherwise plot,cut,etch,...) a photo into an object, simulating different shades of gray by line thickness. The file that the laser (or other machine) would use would be the svg turned to gcode or any other cnc-machine-readable format.

Yes, that would be it although I'm not familiar with operating cnc tools.

On a second thought, making "smarth paths" would be a fitting idea.
Assuming the cnc router carries like an airbrush for example and can control the width of the stroke, it'd come handy if the width data was assigned to a core path which the machine could follow.
Tried to look up some lettering examples drawn striped in the same manner but couldn't find.
This is similar:

[brynn]

@Brynn: He means it's the most convenient way to laser-burn (or otherwise plot,cut,etch,...) a photo into an object, simulating different shades of gray by line thickness. The file that the laser (or other machine) would use would be the svg turned to gcode or any other cnc-machine-readable format.

So you're saying that CNC can be used to print (more or less)?  Because I've only heard of CNC for cutting generally dense material.  I've never heard of it used for printing.

Because I'm thinking of that message, some time ago (https://forum.inkscapecommunity.com/index.php?topic=636.0), where the guy had a photo of his dog  and he wanted to use gcode to make sort of a 3d portrait.  I haven't re-read it, but I seem to recall we referred him to Blender. 

So were we wrong there?  Or is this some new technology since that message?  Could he convert the photo of his dog into the halftone hatch paths, and cut them?

[Moini]

What the poster wanted was a 3D image, so blender was a good choice.

Wikipedia about CNC: https://en.wikipedia.org/wiki/Numerical_control
You will be surprised to learn that even embroidery machines are CNC machines.

[Lazur]

Halftoning means the greyscale levels are represented with black&white only. Yes, that could be engraved but the result wouldn't be as expected in that other topic. Either "bump" or "hole", no elevation/emboss in between.
I thought gcodetools/cnc software could generate a fill pattern for the router based on a solid filled area.
Surely it'd need further tweaking if the cutter didn't just produced a stencil as intended by the user. For that matter it doesn't take bridges into account so it's rather theoretically.
Maybe that line better be edited out to avoid confusion.
Which I did actually, but also remove the rest...
As described before the use process is a bit different, might worth a separate article.
-mentioned template is here-

By the way, the filter editor got some developer focus in the latest hackfest and now a node editor is at least conceptually getting developed.
In the mean time, made a screen recording of this random filter chain, to showcase how to use the current editor effectively:




And, here is the (rather rough/"ineffective") result after a bit of further tweaking:


-Both objects have the same filter chain applied on, but bit different parametres.

[brynn]

Off-Topic: show

I had actually looked at that very same page, to try and figure this out.  But short of really perusing it, doesn't seem to mention anything like printing.  The closest thing I see is 3d printing.  And I have a hard time thinking of 3d printing as laying down the halftone hatch lines.  And except for 3d printing, everything mentioned there is about cutting something out of a generally dense material.  I don't see anything about printing or painting or spraying something.

I'm not really surprised that cnc can be used for embroidery.  But I can't see it stitching out the halftone hatch lines either.  Maybe, I suppose it could do it, but I'm not sure.

Suppose we should make this discussion off topic.

[Moini]

@Lazur: I didn't understand this mockup, but maybe you do: https://inkscape.org/en/~doctormo/%E2%98%85very-rough-mockup-of-filter-editor

[Lazur]

An "in-action shot". Would fine-tune it more however it took two and a half hour to export it -and it was the third time at least.
Probably it is wayyy more effective (time and effort wise) to use raster textures.

-Having technical problems with embedding the image so check the image source.-

[Lazur]

An update to the halftone concept.


^-da image, probably needs further editing for the embedding


^-ocal thumbnail of the same sized png

[Lazur]

Just finished a sayagata/swastika pattern that can make a good use with a halftone template.
Also it was a perfect source for testing woodgrain textures.

[Lazur]

[brynn]

Off-Topic: show

I have an idea I want to try, but I need a file which contains the actual filter (so I can use as a guide).  It looks like you've removed all but the final paths (probably for saving space) for most of these.  Do any of these have the filter still in the file?

I tried message #317, and it has a filter in the file, but I can't seem to bring it into another file.  I apply it to an object, then copy or cut, and paste into a new file, but the filter stays behind.

Could you give me a shortcut to an SVG file which contains a halftone filter (any of them, doesn't matter, just want a guide to try and make my own).

Oh yikes - do we have a new bug?!   I know in the past that I've copied objects with a filter, and the filter is pasted into the new file.  At first I thought it was something funky you did with that file.  But I can't seem to copy a filter into a new file, by just using one of the built-in filters.

Aah, I see.  It converts the filtered object into an embedded raster image!  That seems too complicated to be an accident (i.e. bug).  Wait -- maybe a new pref (new since last time I tried this) ?  Hhmm, not that I can find....

Ok, how the heck can we copy a filter into a different file?

[Lazur]

These halftone filters uses the image filter primitive to pull in a "screen pattern" -pattern filled objec inside the document.
Copy/pasting the filter to another file breaks the link. Maybe copy/pasting the pulled in object work with the filter, although who knows if the id-s will be the same in the new document.

Besides that, the halftone templates have the filter applied to a whole layer as part to being funky.


Here are the templates that can work:

diagonal

wave

sayagata

wave-dot

For a bit mor info on the usage, check the descriptions at ocal and/or in this post.


These are traces of photographs and with ocal's no raster policy I couldn't upload them in an "in action" state.
Can be used on whatever objects but just cannot find a simple AND shaded image with preferably no filters and a wide range on the luminance levels, details etc. that is vector only.


Another note that the pattern object pulled in limits the size of the raster image you can "trace" this way.
With the wave screen pattern it is 8000 px because the object pulled in was only 16000px/16000px and the origin counts from the top left corner of the page (bug?).
If feeling limited, unhide and open the locked layer to resize the rectangle inside.

[Moini]

@brynn: perhaps this one: https://bugs.launchpad.net/inkscape/+bug/1480686

[brynn]

Yikes!  Well I'm on Windows 7.  But I can confirm that everything I try to paste from one doc to another becomes an image!  (posted a comment to the report)

[brynn]

Off-Topic: show

Well, while I can avoid that bug by using 0.91, for most objects, it seems the filter still doesn't come through.  The sample rectangle is pasted, but it has no filter.

Hhm, but according to the Filter Editor, it has a filter, but the filter isn't being displayed.

You'll have to use Ctrl A to find the rectangle in my attached file, the "to" file, but it's there.  I made a  new layer in your file, hoping to avoid any kind of funky stuff you might have done to the file.  I drew a simple rectangle, and filled it with the only filter I could find in the file.  But maybe the new layer wasn't enough to avoid it?

Any chance you could make me a file with a halftone filter in it?  Or show me another file with no weirdness in it?

[Lazur]

Ok, four halftones with different screening of Fuji in one post:









templates used:

diagonal

wave

sayagata

wave-dot

cross

Off-Topic: show

Getting exponentially harder tracking all the collections and tags with this at openclipart. And still haven't put the pixabay links in the descriptions :/

[Lazur]

Any chance you could make me a file with a halftone filter in it?

here is a sloppy as hell video:


Check the description for further details.
With all seriousness, why don't you use the template as it is? Was set up that way for a reason.
Already noted that the filter pulls in another object into the filter chain with the image filter primitive.
Such pulled in objects cannot be embedded right inside the filter chain. Even if it was possible theoretically -didn't dig into the svg specs but have doubts since why would they have the image filter primitive at first place then-, inkscape doesn't have a gui part you could "feed"-embed- objects inside.
It would be a nice feature though to have patterns and gradient fills accessible into a filter chain but that's not a feature either.
Also some scale factor indicators. And ways to break apart/stitch filtering chains. And to setup other vector options in the chain, so that trace bitmap could be used on one hatch filtered object for tracing layered hatching strokes.
The image filter primitive is the only way to achieve these.

Therefore if you managed to copy/paste the filter, you need to copy/paste the pulled in object with it OR pull in another object of choice.
That is selecting the object, and clicking the select svg element in the filter editor at the hatching filter's image filter primitive's settings.
If you do the latter, keep in mind the filter pulls in the object from the top left corner of the page (had commented that at Xav's related topic somewhere). So it needs to be placed at the top left corner of the page and needs to be larger than the object you want to filter.
Too bad it is now covering the page area right?
Well it's better to put it onto a hidden layer. Preferably locked and untouched. Like in a template file.

[Lazur]

collection of templates

[Lazur]

-Berwick upon Tweed upon houndstooth pattern.

[Lazur]

Found this old rss box which however had a raster image embedded which is a no-go at openclipart. So threw in some filters:

[brynn]

Off-Topic: show

With all seriousness, why don't you use the template as it is? Was set up that way for a reason.

Yes, I understand that.  But I wanted to make my own design.  I thought if I could see your filter, I might be able to use it as a guide, to make my own design for the halftone.  I just had the idea to have some kind of geometric image, make a filter with the same geometric design, or similar, and put them together with the halftone tracing.  Like maybe a tesselation or fractal image, with the halftone that is one unit.  Or have a halftone design which complements the image - like you just did with the wool, or houndstooth with sheep.  Like I was thinking to make a peace sign halftone, and put it on a photo of the earth - something like that.

I tried copy/pasting the whole object, not just the filter.  But apparently I'm having that bug, for pasting anything from another file into 0.92.  I think it might be just for 64-bit, but I was falling asleep the other day.  The other day, I was even having trouble with 0.91, although today, 0.91 is ok. 

Oh, nice surprise!  Today pasting is no problem, even in 0.92!  Strange....  Let's see if I can get that filter today....  Oh yay, I got the filter today!  Hhmm, but no I don't think I'll be able to figure it out.  The Component Transfer primitive is WELL over my head, haha!  I didn't realize it was such a complex thing.

Actually I saw your "swastika" made with 4 paisley, joined at the point, and thought of making a paisley halftone and apply to some paisley image (either one I find somewhere, or just make myself).  But I don't think I'll be able to figure it out, even with yours as a guide.

But thanks anyway 

[Lazur]

Like I was thinking to make a peace sign halftone, and put it on a photo of the earth - something like that.

Then you need to draw an actual peace-sign screening pattern. Needs to be repeating, needs to be greyscale with smooth transitions -ie. built up from black-white gradients-. It can even come from a raster image if that's easier.
Most importantly it's best to have all lightness values cover the same percent of the pattern (as much as possible).

Setting up the filter right after is just a few clicks away.

Making the screen image good is the harder part -took me quite a while finishing that pattern pack even if there is nothing fancy inside.

So does this mean you are drawing pattern fills now? Do you have work in progress images?

[brynn]

No I didn't start drawing patterns.  I was just going to try it once.  If I like it, maybe more.

When you say "built up from black-white gradients" do you mean like when you made images, such as on the front page of the gallery, sort of like with many smaller slices, put together to make the whole?  Or do you just mean feathered by some particular ratio?  Sorry, I know I'm not describing it correctly.

Oh ok, I just downloaded the pattern pack.  I guess there must be some reason to create the images with bits and pieces, instead of just blurring black paths?

[Lazur]

Blurring could work too... but would it be stabile to convert a group of filtered objects into a pattern fill?
Not only that but then the filter editor would be loaded with filter definitions of the blurring which is a bit confusing.

[brynn]

Ooohh right!  Because blurring is a filter itself.  You'd have to group it before you went on with the rest of the new filter.  And considering  everything else that happens, it's probably unnecessary added complexity.

Still might try it, just for fun.  We'll see.  Thanks