I have run into an issue where I need to have vertical stroke diameters set to the same vertical diameter size everywhere on the stroke. Normally stroke diameters is the right angle diameter on any location on the stroke and this is constant. But what I want is to have the vertical diameter to be constant, and the right angle diameter to be flexible.

On the image below I show what I mean. The two objects strokes don't match when the objects paths are not horizontal. The more the difference in angle on the two the worse the issue becomes.

I want to do what a calligraph tool does with an angle of 90, only with strokes instead...

Is it possible to somehow set stroke width to become based on vertical diameter instead?





Using the calligraph tool with an angle of 90. I need to do this with strokes instead.

That doesn't exist in Inkscape, as far as I know. What is the use case where you need to do this? I mean, do you just need a couple of objects like this, or do you want to draw a whole large image with that kind of effect?

What happens when the line gets vertical? Does the stroke completely disappear?

brynn wrote:That doesn't exist in Inkscape, as far as I know. What is the use case where you need to do this? I mean, do you just need a couple of objects like this, or do you want to draw a whole large image with that kind of effect?

What happens when the line gets vertical? Does the stroke completely disappear?

It's for a car game, images of sloped platforms of 256px wide. I'm going to have hundreds of pieces like this. In the game I place the images side by side to form a consistent image of the ground the player drives on. If the vertical "diameter" (don't know what else to call it) were the same I would be able to mix and match almost any ground piece with each other. But because it isn't the slopes that are to angled to much won't match with slopes that are not (just as in my example image).

And yes an inherent effect of what I want is that if the line gets completely vertical the stroke would completely disappear and that's okay.

I found out that I could get the effect by using a combination of Stroke to Path and then Pattern along Path extension with parameters ribbon, repeated, 0px space. However it's a tedious process and prone to sometimes crash due to the number of objects that have to be repeated along the path(the objects have to be really thin, like 2px each else the "stroke" result is to uneven). The image below is created this way and the result is what I want.

What's wrong with the calligraphy tool ?

Did you try using transforms and set them preserved in the prefs (Shift+Ctl+P)?
Sounds odd but theoretically possible:

• set transformations preserved from optimised
• draw an infinite wide object on canvas
• group it (Ctrl+G)
• scale the group's width to ~~0
• enter the group, and draw your lines; preferably delete original object.

Adding a transformation matrix may also work via the xml editor (Shift+Ctrl+X), but maybe it will trigger rendering issues somewhere.

For filled paths instead of the pattern along path extension I'd also try the motion.

Lazur URH wrote:Did you try using transforms and set them preserved in the prefs (Shift+Ctl+P)?
Sounds odd but theoretically possible:

• set transformations preserved from optimised
• draw an infinite wide object on canvas
• group it (Ctrl+G)
• scale the group's width to ~~0
• enter the group, and draw your lines; preferably delete original object.

Adding a transformation matrix may also work via the xml editor (Shift+Ctrl+X), but maybe it will trigger rendering issues somewhere.

For filled paths instead of the pattern along path extension I'd also try the motion.

Thank you for the suggestion, however I couldn't make that work, got some weird stuff happen.

v1nce wrote:What's wrong with the calligraphy tool ?

It's much to hard to control for the purpose that I have described. Thickness of the "stroke" with the calligraphy tool will be too wide or too thin at some places, especially in the ends and would require a lot of manual edits to correct.

You can do something based on the following idea. Let's say you want your "vertical stroke width" to be 10px.
- draw a curved line with bézier tool
- duplicate it (Ctrl+D)
- move the duplicate up 10px (you can use eg. Object > Transform, or set the arrow step to 10px in Edit > Preferences > Behavior > Steps)
These two lines will have a consistent "vertical stroke width" of 10px.


To make them into one object:
- select both curves with
- activate node tool
- select two left end nodes and join them with "join selected endnodes with a new segment"
- do the same for the two right end nodes

bartovan wrote:You can do something based on the following idea. Let's say you want your "vertical stroke width" to be 10px.
- draw a curved line with bézier tool
- duplicate it (Ctrl+D)
- move the duplicate up 10px (you can use eg. Object > Transform, or set the arrow step to 10px in Edit > Preferences > Behavior > Steps)
These two lines will have a consistent "vertical stroke width" of 10px.

Capture.PNG

To make them into one object:
- select both curves with
- activate node tool
- select two left end nodes and join them with "join selected endnodes with a new segment"
- do the same for the two right end nodes

Thank you for the suggestion! I wish this would work though, but it seems you are only partly right. It only works right in the middle of the stroke, that is only for the actual path, which is in reality a line with no width. Measured right in the middle of the path the vertical width, from the first stroke to the second, is indeed the same everywhere with your method. But it doesn't work for the 'breadth' of the stroke though. The thicker the stroke and the bigger the angle difference the worse the offset becomes. As shown in the image below you can see the difference in my current solution (using Stroke to Path and Pattern along Path with ribbon effect) and your suggestion (duplicating and offsetting the path):

So you want both the stroke and the filled object to behave the same way -- 0 width at vertical, some defined width at horizontal? In that case, you'll have to create something like a custom stroke, which is really just another filled object. You'll have to duplicate the path from the right side of the filled object, to be used as the left path of the stroke object. Duplicate again, to create the right side. Essentially....well, literally, you'll use duplicates of the same path, for the whole thing.

So let's say you need a fill object (the light green part in your examples) with a dark green stroke on either side.

1 -- draw the path you need
2 -- duplicate
3 -- move it up or down by whatever amount you want for the "stroke" object
4 -- duplicate, but don't move
5 -- duplicate
6 -- move it up or down by whatever amount you want for the "fill" object
7 -- duplicate, but don't move
8 -- duplicate
9 -- move it up or down by whatever amount you want for the "stroke" object
10 -- now go back to the 1st path and the 1st duplicate and select both bottom nodes
11 -- click "Join selected endnodes with a new segment" button on the Node tool control bar
12 -- do the same at the top end
13 -- repeat for the other 2

Edit
PS -- Brilliant solution, bartovan!! I can't take credit for that. Just giving instructions based on his idea

Or just use the calligraphy tool

1 -- draw the path you need (with height = internal height) ; make sure ther's no stroke ; set the fill color as waht you want for "internal" color
2 -- duplicate
3 -- move it down by whatever amount you want for the "stroke" object
4 -- duplicate, but don't move
4 - change fill color for what you want for border color
5 -- duplicate
6 -- move it up by 2X whatever amount you want for the "stroke" object
7 -- select your last 2 copies
8 -- merge them = path / union (ctrl + + )
9 -- lower the selected object (page down)

voila.

toxigames wrote:

Lazur URH wrote:Did you try using transforms and set them preserved in the prefs (Shift+Ctl+P)?
Sounds odd but theoretically possible:

• set transformations preserved from optimised
• draw an infinite wide object on canvas
• group it (Ctrl+G)
• scale the group's width to ~~0
• enter the group, and draw your lines; preferably delete original object.

Adding a transformation matrix may also work via the xml editor (Shift+Ctrl+X), but maybe it will trigger rendering issues somewhere.

For filled paths instead of the pattern along path extension I'd also try the motion.

Thank you for the suggestion, however I couldn't make that work, got some weird stuff happen.

Yes there seems to be some rendering issues but it can work.

Transformed with scale(5e-4,1) parameters.
Stroke width indication is messed up, and some parts are chopped, but those issues can be worked out.

Oh wow some interesting methods and instructions you guys give here! I will certainly try those out tomorrow.

Thanks again

v1nce wrote:Or just use the calligraphy tool

1 -- draw the path you need (with height = internal height) ; make sure ther's no stroke ; set the fill color as waht you want for "internal" color
2 -- duplicate
3 -- move it down by whatever amount you want for the "stroke" object
4 -- duplicate, but don't move
4 - change fill color for what you want for border color
5 -- duplicate
6 -- move it up by 2X whatever amount you want for the "stroke" object
7 -- select your last 2 copies
8 -- merge them = path / union (ctrl + + )
9 -- lower the selected object (page down)

voila.

v1nce, which settings for Calligraphy tool do you use? Isn't it still hard to control with Calligraphy tool?

Did you say why you need this kind of effect? Just curious

brynn wrote:

v1nce wrote:Or just use the calligraphy tool

1 -- draw the path you need (with height = internal height) ; make sure ther's no stroke ; set the fill color as waht you want for "internal" color
2 -- duplicate
3 -- move it down by whatever amount you want for the "stroke" object
4 -- duplicate, but don't move
4 - change fill color for what you want for border color
5 -- duplicate
6 -- move it up by 2X whatever amount you want for the "stroke" object
7 -- select your last 2 copies
8 -- merge them = path / union (ctrl + + )
9 -- lower the selected object (page down)

voila.

v1nce, which settings for Calligraphy tool do you use? Isn't it still hard to control with Calligraphy tool?

Same settings as shown in #1