Xara brush is a scatter one. And if this kind of thing was implemented in Inkscape the Spray Tool would become obsolete for most of its features. However there are no clones in Xara and thus you cannot change all shapes at one time like what is possible with the Spray Tool. The latter also integrates a very usefull boolean union function !

In Xara the Stroke Shapes are only predefined ones and you cannot add other profiles than those which are integrated into the program. You cannot wrap other vector shapes around a skeletal stroke like you can in Expression. You can change locally the width of the scattering area with a pressure tablet or alternatively use these Stroke Shapes.

About bitmap objects stamping and scattering I would see also what could be possible with FeImage and FeTile SVG filters before thinking at a scatter brush. But these primitives aren't completely implemented in Inkscape at the moment. I think a good project for 2012 GSoC would be completing this implementation and adding some features to the Filters Editor.

Thanks a lot for the AI links !

ivan

De : Josh Andler <scislac@...400...>
À : Ivan Louette <ivan_louette@...48...>
Cc : Johan Engelen <jbc.engelen@...2592...>; "inkscape-devel@lists.sourceforge.net" <inkscape-devel@...1239....net>
Envoyé le : Mercredi 9 Novembre 2011 22h31
Objet : Re: Re : [Inkscape-devel] Re : powerstroke

On Wed, Nov 9, 2011 at 1:52 AM, Ivan Louette <ivan_louette@...360...48...> wrote:
> I could try to begin a blueprint (or to complete what already exists).

I don't know what already exists (if anything). If you want to start
an outline in the Wiki, I (and probably others) will help you flesh it
out. Before beginning though, I'd say it would probably help to keep
the vector and complex bitmap aspects separate. Functions like bitmaps
with a "scatter brush" would be fine since it's simply "stamping"
copies and not getting into complex manipulation calculations.

> I am not familiar with what AI does at the moment with brushes but I know
> fairly well Xara brush system (which doesn't work very well in XaraXtreme
> for Linux) and also Expression 3 (before it was bought by Microsoft). The
> latter was even available for free some years ago and I install it with Wine
> every time I install a new Ubuntu on my machines ; it works without any
> problems on Wine.

I installed Xara on linux to test out the brushes and the most
interesting aspect was the Stroke Shape / Pressure Profile widget. I
assume that you can add new shapes with pressure data from a tablet,
is that correct or just oddly named? I need to install Expression
again. I really didn't dig too deep in the past, but I recall from
tutorials the bitmap manipulation for brushes was impressive. A bonus,
since we have access to the source for Xara Extreme LX, their pressure
profile aspect can be looked into.

For reference, here is mostly current info about brushes in AI:
http://vector.tutsplus.com/tutorials/tools-tips/a-comprehensive-guide-illustrators-paintbrush-tool-and-brush-panel/

If Inkscape's implementation also includes the Scatter Brushes like AI
has, I think it probably deprecates the Spray tool.

This brush type is separate as it was just introduced in CS5:
http://vector.tutsplus.com/tutorials/tools-tips/create-a-painterly-apple-with-illustrators-new-bristle-brush/

> Xara system only align vector or bitmap elements along paths without
> deforming them (it only changes their individual size with pressure
> sensitivity) and adds some rotation, resizing, etc. There is no controls on
> pressure results after drawing a path and if you modify original objects the
> result isn't changed in the brush.

One challenge will be how to handle the pressure results given how
over-the-top complex the data can be (especially if factoring in
pressure and tilt/rotation). Perhaps we allow a complexity/smoothness
control similar to the pencil tool.

Before anyone gets too excited, no one has expressed a desire to work
on nor committed to working on this stuff. Right now we're just
looking to make a really awesome blueprint.

Cheers,
Josh