Polygonal designs and intersections

[grit]

I would like to make this polygonal designs. I know how to use line tool but is there a way
to place other shape (like dot, circle, cube) in center of intersection of 2 lines?

If I just draw circle of cube, it gets inprecise.

[rich2005]

Probably some dedicated graphics application, although it might be more general, using a vector application such as Inkscape. (someone will know    )

Using Gimp and some old scripts (attached)

   

First what do you know about Gimp and unicode. Every character has a code including those that are not on the regular computer keyboard. You can get these in Gimp by holding shift-ctrl-u then enter a code.

   

Lists of unicode categories https://www.compart.com/en/unicode/category

You will need to make your shapes using paths, which is not a bad idea anyway, various tools for that, I use the attached script shape-path.scm but Ofnuts has a comprehensive tool in http://sourceforge.net/projects/gimp-pat...s/scripts/  ofn_path_to_shape 

A quick video demo:





direct link https://youtu.be/v3dGGBr1xY8 duration about 4 minutes 30 secs

[Ofnuts]

I have a script (which I used to make the doc of ofn-path-to-shape) that put circles on the anchor of a path. Not too hard to change to put squares/diamond or any random brush. Of course you would need to have anchors on each intersection. Let me see what I can come up with.

[grit]

I didn't want to open new thread cause I have a similar problem.

I created this with ellipse tool and border. I manually placed another circle on bigger one and erased the arc of the bigger circle.
Is there better/faster more accurate way to do this with ofnuts path tools?

   

[Blighty]

(02-17-2019, 06:01 AM)grit Wrote: I created this with ellipse tool and border. I manually placed another circle on bigger one and erased the arc of the bigger circle.
Is there better/faster more accurate  way to do this with ofnuts path tools?

Do you need to do in Gimp? This is very easy to do in Inkscape.
If necessary, the Inkscape svg file can be imported into Gimp as paths.

EDIT: I have played with Gimp's paths and it is quite easy to do in Gimp
I will put something together.

[Blighty]

Create a circular path
There are various ways to this. There is the arakne path shape creator, but it does not work on my Gimp. So I use another one, shape-path.
It can also be done by creating a circular selection and then Select > To Path. Not as neat as using the path tools.

Create the second, smaller circle
Either work from scratch, or duplicate the first path and resize it with the Scale Tool set to path mode.

You now have something like this:
https://imgur.com/a/7wkuLIA

Move small circle into position
Use the Move Tool, set to path mode, to move the small circle so that the centre of the small circle is on the big circle.

Add additional nodes to the big circle.
In the Paths Dialogue, select the big circle. The path will change to red.
Ctrl-Click on the intersection an intersection of the big and small circle. This will add a new node.
Do the same for the other intersection.

You now have something like this:
https://imgur.com/a/KrWp4mZ

Delete portion of big circle
Using the Path Tool, click on the portion of the circle between the 2 new nodes to select it.
Shift-Ctrl-Click it to delete that portion.

You now have this:
https://imgur.com/a/jJxVv0o

If necessary, right click on a path in the Paths Dialogue and do Merge Visible Paths

Paths are now complete.
Use Edit > Stroke Path to stroke the path.

For more information on paths, see:
https://www.gimp-forum.net/Thread-Working-with-Paths

[Ofnuts]

(02-17-2019, 06:01 AM)grit Wrote: I didn't want to open new thread cause I have a similar problem.

I created this with ellipse tool and border. I manually placed another circle on bigger one and erased the arc of the bigger circle.
Is there better/faster more accurate  way to do this with ofnuts path tools?

With several functions in ofn-path-to-shape:

• Create a left-to-right line (this will be the line between the center of the two circles)
  
• Use it as the radius of a circle (Shapes>Segment>Circle)
  
• Create a small segment, that starts where the first ends: Shapes>Segments>Transform segments>Resize and use Start=100% and End=80% (100% should be on the Start for the next operation)
  
• Use that new segment as the radius of a circle.
  
• In the path tool, select the bigger circle and click on it to make its anchors appear
  
• Zoom in and Ctrl-click where the big circle intersects the small one to add two anchor to the big circle
  
• Ctrl-Shift-click the anchor of the big circle at the center of the small to remove it, and then Ctrl-Shift-click the segment of the big circle between the two anchors you add to remove it. 
  

   

[grit]

Thank you all.

Ofnuts, did you talk to GIMP developers? Maybe they can implement your path tools into one consistent UI tool section/module in GIMP 3x. This would be very nice.

[Krikor]

(02-17-2019, 09:25 AM)Ofnuts Wrote: With several functions in ofn-path-to-shape:

• Create a left-to-right line (this will be the line between the center of the two circles)
  
• Use it as the radius of a circle (Shapes>Segment>Circle)
  
• Create a small segment, that starts where the first ends: Shapes>Segments>Transform segments>Resize and use Start=100% and End=80% (100% should be on the Start for the next operation)
  
• Use that new segment as the radius of a circle.
  
• In the path tool, select the bigger circle and click on it to make its anchors appear
  
• Zoom in and shift-click where the big circle intersects the small one to add two anchor to the big circle
  
• Ctrl-Shift-click the anchor of the big circle at the center of the small to remove it, and then Ctrl-Shift-click the segment of the big circle between the two anchors you add to remove it. 
  

I had tried to reproduce this figure initially using the steps indicated by Blighty, but it was difficult to get the desired result as the segment always cut off the intersection between the circles (either before or after).
So I tried Ofn-path-to-shape. Since installing this script I never knew how to use it, and I had already forgotten about it, I even downloaded it again today to find that it was still installed.

Following the steps taken by Ofnuts was surprisingly easy, the seven-headed monster seemed friendly. But I caught in step 6:
"Zoom in and shift-click where the big circle intersects the small one to add two anchor to the big circle".

After insisting unsuccessfully, I experimented with ctrl+click (and voilà), and got both anchors at the intersection points of the circles and ended with ctrl+shift+click.

The result was perfect, very easy and the cuts being made at the intersections.

It would be nice if there were more tutorials on how to use this script.

I also found that I already had the shape-path.scm script when I followed the steps of Rich2005, only in a more current version (that's what I deduced).

So I will make this version available here for anyone interested. 

PS.: Sorry "Please correct the following errors before continuing:

• The type of file that you attached is not allowed. Please remove the attachment or choose a different type."
  
  
  
  
• Neither .rar nor .scm Files Seem to Be Allowed
  

PS02: This script can be found at http://gimpchat.com/viewtopic.php?f=9&t=...10#p238042

[Ofnuts]

(09-19-2019, 09:32 PM)Krikor Wrote: PS.: Sorry "Please correct the following errors before continuing:

• The type of file that you attached is not allowed. Please remove the attachment or choose a different type."
  
• Neither .rar nor .scm Files Seem to Be Allowed
  

PS02: This script can be found at http://gimpchat.com/viewtopic.php?f=9&t=...10#p238042

You should have tried ZIP (RAR is proprietary (no open source version) while ZIP is an "open" format).