Hello,

Quick question : how is it possible to apply path effects so that the resulting path can than be sculpted ?

A bit more context :
I am trying to produce a schema similar to that one :


Notice the crimson-pink structure ? This is the one I am trying to reproduce, but from the top view.
So I used LPE to create a repeated rectangular pattern and a circular path. Now I would like to "apply" this effect to obtain a path of the repeated rectangles, which I would then edit with the tweak tool. Is it possible ? If not, is there an other way around to achieve this ?

Thank you for your time !
G.

Welcome to InkscapeForum!

Oh, great illustration, and very interesting problem!
Is there some reason that you want to use Pattern Along Path? Like for example, you need to use the pattern more than once for just this image? Because if you just need it once, I think I would just flat out draw it, perhaps like you've made the pattern. Oooh, I think I understand now. The pattern needs to go all the way around the nucleus, and not just in the area where we see it in the illustration?

I'm embarrassed to say that I've forgotten so much science that I learned so long ago. I don't recall exactly what the endoplasmic reticulum does, and at first didn't realize it apparently, if I understand correctly, sort of encases or contains the nucleus. Or maybe it's new science? I really don't recall a smooth and rough version....

Anyway, so you've drawn something like a section of brick wall type of pattern? And then you need it to stretch around the circle (using pap), and then use Tweak tool. That sounds like a good plan, except that I'm with you. I'm not sure if the Tweak tool can be used on the result. I have to admit that Pattern Along Path has given me fits over the years I've been using Inkscape. I'll have to try to recreate what I understand that you're doing, or at least some representative sample and try it myself, before I can say for sure.

Of course someone else may come along with that knowledge already at hand. But that's fine -- I just like to learn!
If no one else has replied by the time I figure it out, I'll let you know what I learn

Edit
Well, I actually got a working example done pretty quickly, lol!
So yes, Tweak can be used on the result, but it won't have exactly the effect that I think you want. The Tweak tool only affects the original circle path, so that the individual rectangles get tweaked pretty much as a whole. So for example, instead of something like on the left, the rectangles will be more like on the right:

There might be a couple of ways to get around that. One is that you could tweak the rectangles before you apply them as the pattern. Based on my quick tests, I think you might need to make the pattern repeatable, meaning that each pattern will merge into the next pattern, without being obvious that it's a repeated pattern. That could get tricky.

So the other way I'm thinking is instead of several "rows of bricks" for the pattern, it would just be one row (tweaked before applying as pattern), but that you would have several concentric circles. I think this would appear more random after finished. You could tweak the rectangles before applying as pattern, and you could also tweak the result a little bit. And after you have however many concentric circles (looks like it would be maybe 5 or 6?) each of them tweaked separately, it would really look random. Or you could tweak the circles first, instead of afterwards, tweaking each circle a little differently.

A couple of tips with the Tweak tool. Certain modes have a tendency to create enourmous quantities of nodes, which can potentially bog down Inkscape. I didn't get anywhere near that point in my test, but I just wanted to mention it. Ironically, I had to create extra nodes in my 4 node rectangular path to get the right effect.

OH! Or I just thought of another way to approach the whole problem! This is assuming that I do understand the problem correctly There would probably be more of a learning curve for this, though. But I think you could do a pretty good job using tiled clones, because there are settings for randomization. Edit menu > Clones > Tiled Clones. In Help menu > Tutorials > Tips and Tricks, there are instructions for making radially tiled clones. It sounds like there may be a few ways to accomplish it, but I've been fairly successful (not at this moment, but a week or so ago) making radially spaced clones, which leads me to think it might work. Hhhmmm....actually the tweaked rectangles would probably look very similar though, because the randomization settings affect placement, rotation, color, blur, and not the shape of the clone. You might be able to use 3 or 4 sets of radial clones, around the same center, using 3 or 4 different tweaked rectangles as originals. But by the time that you go to all that trouble, you might as well draw the whole thing from scratch. But it would be an interesting challenge to try

Anyway, let us know how it goes. (And especially if I'm not understanding the problem correctly )

i assume that you're making it simpler by using rectangles along multiple size circle paths..because the original has some bits that join up, somewhat like a letter H in a recurring pattern. For the simplified case I'd use create clones rather than pattern along path, to place repated rectangle along a circle parameter. Can you use the 'ol trig formulas for the positioning of each clone? Or is it just my brain melting at end of working day and it's much easier than that?
In any case if it works out using clones, you can then unlink clones and tweak individual bits manually. In LPE afaik there's no way to tweak individual bits..it's ALL a pattern along a path or nothing.

Wow !

First, thank you for your answers : they were both encouraging and enlightening.
You understood the problem well. My goal was to create a basic layout using PAP and then tweak it to have the desired look. I drawed a circle representing the nucleus, and then duplicated this circle in many concentric circles that would be my paths for each layer of the reticulum. This is what I obtained :


The red rectangle in the center is the pattern that is used for the path effect for the 2 circles enclosing the circle representing the nucleus.
Now, what I was trying to do, was to find a way to convert the entity "path+path effect" of the first level to a compound path. Like take a static snapshot of what is represented right now (the same way "object to path" works). It is quite difficult to explain, I must admit .
If you know a bit of Blender, this is how modifiers work. If you add a mirror modifier to a mesh you get a dynamic representation of mirror of this mesh : any modification you make on the mesh is reflected on the mirrored version of it. Now if you apply the modifier, then the mirrored mesh becomes part of the original mesh. And any modification made to the original part of the mesh is not reflected to the mirrored part of the mesh, since there is no mirror modifier anymore. This was what I was looking for.

But with the paving clone technique, I should be able to achieve what I am looking for (paving with an angle at each iteration, unlink the clones, adapt them).
So a big thanks to you guys, since you pointed me in the good direction (although I am not too comfortable with the clone paving technique )

As for the biology part, it's more than OK not to know/remember all this stuff. I do this scheme for my wife, for a presentation she has to do. So if it wasn't about that, I'm sure I wouldn't remember either
The role of the reticulum is to transport and mofify proteins that will be used outside the nucleus and the cytoplasm (in the membrane, usually), for what I have understood, but I would rather suggest to go through the Wikipedia article. But it is indeed fascinating

Thank you and nice week end to you !
glat'

Hi glat',
Oh, that's a great start! You can rotate the circles to make the individual "rectangles" partially overlap (instead of entirely overlapped). They would better represent the reference image.

I didn't know this yesterday, but since you asked specifically about turning the path effect into a path, I thought to try Object to Path. It does work! So select each circle of rectangles, and do Path menu > Object to Path. Now the tweak tool will do a better job on them. You could even do further, Path menu > Break apart to make them individual again (rather than compound). That would allow even better randomization.

And now that I know that, I think I would go back to the "brick wall" as a pattern. As I said before, it would be tricky to make it tilable. But since we now know that you can convert back into individual bricks, you can move them around slightly, and not need them perfectly tiled.

I'm not familiar with the "paving clone" technique that you mentioned. (Or maybe I just don't recognize that name for it.) There is SO much more to learn about Inkscape, lol! Anyway, while I was looking for it, I found this page: http://tavmjong.free.fr/INKSCAPE/MANUAL ... ricks.html, which sounds easier to me than the radial clones in the Tutorial that I mentioned.

So I guess it's going to come down to trial and error, and which technique gives the better result. I think you'll do fine with pap and tweak, especially now that we know that the effects can be made back into paths. For me, the tiled clones take a new learning curve everytime I use it, lol.

Anyway, happy drawing

Oh this is so good !

That "Object to path" trick was exactly what I was looking for ! Now I can roughly create my layout in a couple moves and then tweak it to be more natural.
Thanks a million, this really makes my day

Regarding the clone paving it was a mistake, I meant clone tiling. I think it was a memory of the french version of the clone tiling menu option ("Créer un pavage de clones")

So now I go back to the drawing. I must speed up : the plain version is for tomorrow evening !
Thank you for your time, I will post the result when it is over (in 2 weeks, I guess)

Good week end,
glat'

Awesome, I can't wait to see it