Hi,
is there some easy way to achieve effect like this:

(this was created manually)

I have a line or curve and need to create something like envelope curve around my line in some constant distance from my curve. I tried various effects and extension but I am still unable to do, what I need.

any advice would be nice

thanks

This was done so:
1. Create a line - stroke, no fill, butt cap (not a clothing item!)
2. Duplicate (ctrl+d) and send to back, leave selected.
3. Change cap style to square. Increase stroke width as desired.
4. Stroke to path, change fill colour and give it a stroke (good dog!) as desired.



Works with curves as well, and, if you want round corners you can choose that option - as well as round caps - in the f/s dialog BEFORE doing the stroke to path.

You can do it with clones, too, and the clones will follow the original line.

Draw a line and set it's fill to none and stroke to unset. (it will disappear)
While selected do Edit->Clone->Create Clone and set its stroke to black, width to whatever you want (this makes the outer outline) say 10px and cap to square.
Select the original with shift-D
While selected do Edit->Clone->Create Clone and set its stroke to yellow, width two pixels smaller (this makes the yellow line)to get a 1 px black outline.
Select the original with shift-D
While selected do Edit->Clone->Create Clone and set its stroke to black, width two pixels (this makes the center line).

You can edit the line by clicking on any of the objects then shift D to get the original then edit it with the node tool.

-Rob A>

A little less precise, but Linked Offset would do it as well.
1. Draw curve or line. Convert stroke to path.
2. Path>Linked Offset, adjust to desired width and stroke/fill colors.

If you adjust the original path shape the offset will automatically adjust as well, but since you changed the original stroke to path you will probably need to grab two nodes at once to modify the original path.

(this was created manually)

I have a line or curve and need to create something like envelope curve around my line in some constant distance from my curve. I tried various effects and extension but I am still unable to do, what I need.

I'm not aware of an extension or filter that will do this automatically. But you could search the internet, because many are written which aren't included in the program. However I suspect that none exist

Why is it that you need this done via filter or extension? If you could describe your project, maybe we could come up with another way to meet your needs?

Edit
Unless maybe Extrude??? (Extensions > Generate from Path > Extrude). Oh great, of course Inkscape crashed when I tried to experiment. I will return with results.
Or maybe try your hand with Filter Editor??

brynn wrote:Why is it that you need this done via filter or extension? If you could describe your project, maybe we could come up with another way to meet your needs?

Thanks for reply,
in fact I am trying to make my graphs more attractive (I create them in Scidavis and then export to SVG) and convert the graph polylines to tube like structure. I created it once manually and it had a big success so I was asked to make it again. It is graph for just a global overview of the variable behavior so I do not need to be highly exact.

Aaaah....hhhhm....
Unfortunately, I think you may be stuck with "manually". Hopefully the suggestions presented by the other responders can help speed it up some. OH! Well you could probably get some interesting results with filters, but not exactly like your example....well, unless you made your own filter....
What about a tube or cord-like appearance? Here's a short tutorial from the Inkscape website: http://inkscape.org/screenshots/gallery ... D-rope.png.

Oh wait -- could this be done with pattern along path? It seems to me that it should, but I can't seem to get it to work. I always have trouble with pattern along path, and haven't learned yet what throws me off. But it seems to me that it should be possible??? Yes? No?

Oh, and another idea -- markers?

Watch out -- throwing ideas around!