Hi!

Please check if http://hopey.nervo.org/~gwidion/marble_1.png is close to what you want.

And tell me whether you have pygimp (Shows up as a Python-fu menu option) installed.

Regards,
JS
->

On Wednesday 15 June 2005 17:23, Giles wrote:

Hello.

As I alluded in a previous message, there's a reason I'm lurking about on the gimp-developer list and it isn't that I'm a gimp developer. I've used Linux since 1994, and the GIMP for ... several years. Not sure how long.

In 2003 I went to Venice and fell in love with marbled papers. I would really like to be able to recreate those papers with the Gimp, preferably with wrap so they would tile. There are some parts of the process that you can pull off with the Gimp as it is now, and some you can't.

The best book I've found on the process is this one:

Marbling Paper and Fabric by Carol Taylor, 1990. Sterling, New York.

Unfortunately I haven't found a good photographic record of the process of creating marbled paper online. There are plenty of other books though. You can see examples of marbled paper at http://www.gilesorr.com/Venice/marbled/ - these are scans of part of each of the papers I brought back with me. You could also take a look at what I consider two of my more successful Gimp attempts:

http://www.gilesorr.com/images/200305/VenetianMarble05.html http://www.gilesorr.com/images/200305/SlideUpwards02.html

Or just look at that whole lot, http://www.gilesorr.com/images/200305/ to see a bunch of my Gimp tiles and a lot of not-so-good marbled paper attempts.

The parts of the process that would need to be recreated in Gimp plugins follow:

- adding paint - essentially localized spraying/spotting (different size of dots, not perfect circles, random scatter) - some way to vary brush size (ie amount of paint, size of dots) - needs wrap
- since it's paint on size (a form of paste on top of the water), it needs to _push_ other dots rather than just overlaying them - combing (or single stylus)
- I would like wrap, stroke path, and by hand - specialized combs - boquet comb in particular, two rows of alternating teeth
- again, the way it pulls the paint should mimic the physical world - shaking the tray
- blowing on it as with suminagashi (http://www.suminagashi.com/ - this process isn't a priority for me)

I've been planning to offer a bounty for this, but my $50 is sounding fairly small compared to the recently posted Gnome bounties. I assume the Gnome bounty code is released GPL, and that's what I'd expect here.

So, questions: is anyone interested in working on this? Should I separate the parts and offer bounties (they'd have to be smaller) on each of the individual parts? How could all of this be handled? Is there somewhere else I should post a request like this?

-------------------------------------------------------------- Giles giles@dreaming.org http://www.gilesorr.com/
--------------------------------------------------------------

On Thursday 16 June 2005 04:23, Giles wrote:

The parts of the process that would need to be recreated in Gimp plugins follow:

- adding paint - essentially localized spraying/spotting (different size of dots, not perfect circles, random scatter) - some way to vary brush size (ie amount of paint, size of dots) - needs wrap
- since it's paint on size (a form of paste on top of the water), it needs to _push_ other dots rather than just overlaying them - combing (or single stylus)
- I would like wrap, stroke path, and by hand - specialized combs - boquet comb in particular, two rows of alternating teeth
- again, the way it pulls the paint should mimic the physical world - shaking the tray
- blowing on it as with suminagashi (http://www.suminagashi.com/ - this process isn't a priority for me)

So, questions: is anyone interested in working on this?

I'd be interested in seeing it happen, but have very little time and approximately zero ability with "real world" artistic media.

My wife used to use a graphics package under MS-Windows 3.x a decade or two ago, which had been ported from the Mac. The package (name eludes me) understood how things like charcoal, chalk and watercolours were supposed to work (crumbliness, spatter, the way things tend to slide rather than stick as the force goes up (and eventually crush), brush-hair lines in the paint trail, the ability to _twist_ the applicator, that kind of thing). Simply recreating that ability would be a very noble goal and would bring a phalanx of artists aboard GIMP starting the day after it was released, no worries.

Of course, since GIMP has layers and the original did not, you could assign arty values to specific layers such as viscosity, dryness, absorbancy, graininess and various kinds of "alpha" such as being-pushed-around-alpha, influencing-the-texture-alpha, perhaps being-wet-alpha, so you could do things like paint onto a "silk screen" or "flywire" and then remove the screen, leaving the grid and the brush-hair-tip flicks and so on behind, or simulate the effect of varying "absorbency texture" (think of a half-dried leaf, which absorbs more of the pigment in the thinner areas) on a "wet" paintbrush.

I'd be interested in adding USD$50 to a bounty for any significant part of that - more if I had it, I think the original package was worth ~AUD$1200 at the time. (-: /ME dreams of clicking "Layer -> Physics -> Thin Wet Oil Paint on Galvanised Iron" or "L->P-> Burnt Stick on Rammed Earth", or drawing with sky-blue charcoal :-)

Cheers; Leon

On Wednesday 15 June 2005 10:13 pm, Leon Brooks wrote:

My wife used to use a graphics package under MS-Windows 3.x a decade or two ago, which had been ported from the Mac. The package (name eludes me) understood how things like charcoal, chalk and watercolours were supposed to work (crumbliness, spatter, the way things tend to slide rather than stick as the force goes up (and eventually crush), brush-hair lines in the paint trail, the ability to _twist_ the applicator, that kind of thing). Simply recreating that ability would be a very noble goal and would bring a phalanx of artists aboard GIMP starting the day after it was released, no worries.

You might want to have a look at krita which is part of the upcoming KOffice 1.4 release. It is designed specifically to do the types of things you are talking about. It is still under heavy development and is currently in what is probably a beta state.

On Friday 17 June 2005 04:22, Hal V Engel wrote:

On Wednesday 15 June 2005 10:13 pm, Leon Brooks wrote:

My wife used to use a graphics package under MS-Windows 3.x a decade or two ago, which had been ported from the Mac. The package (name eludes me) understood how things like charcoal, chalk and watercolours were supposed to work (crumbliness, spatter, the way things tend to slide rather than stick as the force goes up (and eventually crush), brush-hair lines in the paint trail, the ability to _twist_ the applicator, that kind of thing). Simply recreating that ability would be a very noble goal and would bring a phalanx of artists aboard GIMP starting the day after it was released, no worries.

You might want to have a look at krita which is part of the upcoming KOffice 1.4 release. It is designed specifically to do the types of things you are talking about. It is still under heavy development and is currently in what is probably a beta state.

Thanks for that! The Krita page here...

http://www.koffice.org/krita/

...mentions that Krita (apparently AKA KImageShop) was inspired by Fractal Painter - the program whose name I couldn't remember - which is now known as Corel Painter IX:

http://www.corel.com/painterix/home/

It also acknowledges The GIMP for inspiration (yay!) and points to this:

http://members.ozemail.com.au/~hodsond/gimpbrush.html

My New Financial Year (here in Oz, anyway) Resolution is to have a look at Krita and see what if any of its technology can be cross-pollinated into The GIMP (perhaps as a plugin to start with).

Failing anything useful eventuating by the end of July, please nag me to start mucking around with, what shall I call it? "Media" is too easily confised with other stuff, so perhaps "applicators?"

Cheers; Leon

-- http://cyberknights.com.au/ Modern tools; traditional dedication http://plug.linux.org.au/ Member, Perth Linux User Group http://slpwa.asn.au/ Member, Linux Professionals WA http://osia.net.au/ Member, Open Source Industry Australia http://linux.org.au/ Member, Linux Australia

Leon Brooks wrote:

It also acknowledges The GIMP for inspiration (yay!) and points to this:

http://members.ozemail.com.au/~hodsond/gimpbrush.html

Sadly, I've lost the prototype code that I wrote (although it shouldn't be too hard to rewrite). The tricky part is building a user interface that makes the whole thing usable.

On Fri, Jun 17, 2005 at 06:53:20PM +1000, David Hodson wrote:

Leon Brooks wrote:

It also acknowledges The GIMP for inspiration (yay!) and points to this:

http://members.ozemail.com.au/~hodsond/gimpbrush.html

Sadly, I've lost the prototype code that I wrote (although it shouldn't be too hard to rewrite). The tricky part is building a user interface that makes the whole thing usable.

i am curious if this could do the work:

http://pippin.gimp.org/image_processing/index.html examples of it working on a whole image can be found here: http://pippin.gimp.org/plug-ins/gluas/examples/

carol

Carol Spears wrote:

Leon Brooks wrote:

[...]
http://members.ozemail.com.au/~hodsond/gimpbrush.html

i am curious if this could do the work:

http://pippin.gimp.org/image_processing/index.html

No. If you read the link, you'll see that it's talking about processing the brush parameters, not the image pixels.

Hi,
leon-gimp@cyberknights.com.au (2005-06-17 at 0858.12 +0800):

Failing anything useful eventuating by the end of July, please nag me to start mucking around with, what shall I call it? "Media" is too easily confised with other stuff, so perhaps "applicators?"

You missed an interesting page:

http://www.levien.com/gimp/brush-arch.html

GSR

On Saturday 18 June 2005 03:33, GSR - FR wrote:

You missed an interesting page:

http://www.levien.com/gimp/brush-arch.html

True. A preliminary/general comment on that is that I think we do need all of the confusing bells and whistles spoken of, but also a much-simplified way of saying "I want to draw with this tool on this surface" plus maybe a handful of sliders for things like "wetness", "roughness" relating to the medium and "wetness", "crumbliness", "viscosity" etc relating to the drawing implement.

It might be interesting to be able to "dry/cure/harden" in real time to give an even more natural effect. Complete with things like a pause button to make up for the nonexistence of mobile 'phones in Renoir's day. Or possibly to do unnatural things like "un-dry" the paint, do some strokes, "dry" it again, do more strokes, "un-dry" again, etc.

The "higher-points-attract-more-pigment" surface model seems a bit simplistic to me, I'd expect steeper slopes to accumulate more pigment (a la Peter Mattis) and some pigment (especially for dry implements like chalk and charcoal) to accumulate in the lowest-lying regions, but it's probably good enough for most things, and certainly good enough for a start. Complicate things later.

One such complication might be a "paper angle" control to make tool dust fall and wet pigment run in different directions at different rates. It would be cool to be able to (not on by default) believably simulate ink dribble and paint-blob sag.

Curtis's watercolour simulations may no longer be too computationally intensive, now that eight years (!) have passed, or may have been improved upon. Certainly worth investigating. I think that rather than setting a specific wetness value, the brush should reduce the difference between the bursh's wetness and the medium's wetness - so in principle applying a dryish brush to a very wet medium should actually dry the medium out a little.

I think we need a single word for brush/chalk/charcoal/implement or whatever, and I think the correct, not-previously-used word is "stick". It has that slightly confrontational tone which should make it memorable and attract mention in reviews, but the basic idea is that it is either a stick of chalk/charcoal/crayon or a stick with a brush, pad or whatever attached to the end of it. Or possibly a hollow stick, if we're simulating a nib pen or straw.

Cheers; Leon

-- http://cyberknights.com.au/ Modern tools; traditional dedication http://plug.linux.org.au/ Member, Perth Linux User Group http://slpwa.asn.au/ Member, Linux Professionals WA http://osia.net.au/ Member, Open Source Industry Australia http://linux.org.au/ Member, Linux Australia

On Sat, 18 Jun 2005, Leon Brooks wrote:

On Saturday 18 June 2005 03:33, GSR - FR wrote:

You missed an interesting page:

http://www.levien.com/gimp/brush-arch.html

Curtis's watercolour simulations may no longer be too computationally intensive, now that eight years (!) have passed, or may have been improved upon. Certainly worth investigating. I think that rather than setting a specific wetness value, the brush should reduce the difference between the bursh's wetness and the medium's wetness - so in principle applying a dryish brush to a very wet medium should actually dry the medium out a little.

If you really want to know what can be done with todays hardware, watch the video's Bill Baxter has made available for his Dab and Impasto projects: http://www.billbaxter.com/projects

Boudewijn

On Sat, Jun 18, 2005 at 02:06:55AM +1000, David Hodson wrote:

Carol Spears wrote:

Leon Brooks wrote:

[...]
http://members.ozemail.com.au/~hodsond/gimpbrush.html

i am curious if this could do the work:

http://pippin.gimp.org/image_processing/index.html

No. If you read the link, you'll see that it's talking about processing the brush parameters, not the image pixels.

yeah, you caught me. i scanned the page you mentioned and then did that gimp developer trick to see if i could get people interested in gegl.

the well written original page probably more than deserves more of my attention.

/me looking for my thinking (concentration) cap carol