Re: [Gimp-user] Editing a stroke

[Steve Kinney <admin pilobilus net>]

On 02/09/2017 08:21 AM, akovia wrote:
> On Tue, Feb 7, 2017, at 07:46 PM, KayInFL wrote:
> > After I have created a path and applied a stroke, is it possible to edit
> > the
> > stroke (to change color, width, dash/dot, etc.)? I am annotating a map
> > and am
> > not sure what the best line characteristics should be, and won't really
> > be able
> > to tell until I have all the paths stroked so I can see how they all look
> > together.
> >
> > -- 
> > KayInFL (via www.gimpusers.com/forums)
>
> You can't dynamically edit the stroke effect (yet?), but as long as you
> are applying the stroke to a separate layer/layers and not on the map
> layer, you can change it as much as you want. Either use the undo
> (CTRL+z) if you don't like the results, or make a bunch of stroke layers
> with different effects and turn the visibility on and off for each so
> you can see the differences.

Another way:  Make your paths, and make them visible on the image canvas
by clicking in the left-most column in the Paths dialog dock - an
eyeball will appear where you clicked, and the paths you make visible
will appear on the image canvas as thin red lines.  This, so you can see
them and make sure they are all present and in the right places as you
proceed.

Then, add a transparent layer, and save your XCF file.  Save your XCF
file again, with a new name - i.e. add "-2" to the end of the name.  If
anything goes wrong with the steps that follow, you will be able to
reopen the first XCF file you saved per above, re-save it with another
name and proceed, with no work lost.

Add a transparent layer.  In the Layers dialog dock, left click and do
"Merge visible paths."  If some paths will have a different color,
width, or etc. than others, merge the paths in groups by making only the
one that are all going to have the same appearance visible.

Now you can stroke your paths (or groups of paths) on the transparent
layer (or different transparent layers for groups of paths), undo with
Control+z, redo with different stroke settings, etc., until you get the
results you want.

To change just the color of paths already stroked on a transparent
layer, go to the Layers dialog dock and lock the layer's alpha channel
(this toggles off and on via a small buton at the top of the Layers
dialog dock, with a checkerboard pattern on it).  Drag and drop your
color of choice from the color picker, and/or make adjustments with any
of the color tools (i.e. Hue-Saturation, or etc.).

The ability to edit the "stroke" applied to a path directly will not be
likely to appear in the GIMP any time soon, as that would require adding
a lot of code that is already native to vector editors like Inkscape.
In fact, Inkscape might be a better tool for creating line drawings (and
text) over a bitmap image; you could import the bitmap image of your map
into Inkscape, select it as an object, and adjust the Page to the size
of the selection.  Then create, manipulate, stroke and edit your lines
and text any old way you want.

Since you are already familiar with the GIMP, Inkscape might not be the
best option for your current project; it has quite a learning curve.
But if you do this kind of work a lot, it may be worth looking into.

:o)

Steve