Bi-concanve

Post questions on how to use or achieve an effect in Inkscape.
mmohaqeqf
Posts: 3
Joined: Sun Feb 28, 2016 8:05 am

Bi-concanve

Postby mmohaqeqf » Sun Feb 28, 2016 8:09 am

Hi everyone;
I am new to Inkscape !!
I am going to use it to draw some simple and elementary shapes for my journal article.
For now, I want to draw a 2-d biconcave shape representing red blood cell (like the lower one in the attached picture).
Any help would be appreciated.
I keep posting my questions as I go along :-)
Thanks
Attachments
RBC.jpg
RBC.jpg (8.69 KiB) Viewed 1201 times

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brynn
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Location: western USA
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Re: Bi-concanve

Postby brynn » Sun Feb 28, 2016 8:57 am

There are several ways this can be done.

For the lower image, I would suggest importing the raster image into Inkscape, and tracing using the Pen/Bezier tool. Tips:

-- zoom into until the shape fills the whole canvas
-- place nodes maybe 50 to 100 px apart (roughly) along the outline (click once with Pen/Bezier :tool_pen: tool to set nodes)
-- place them closer together in the tighter curves and further apart along the gentle or nearly straight curves
-- when you come back around to the 1st node, click once inside the tiny square, to close and end the path
-- switch to the Node tool :tool_node:
-- adjust any nodes that might not be exactly on the outline (just drag them with Node tool)
-- Ctrl + a (selects all nodes)
-- click "Make selected nodes smooth" button on the Node tool control bar (looks like Image)
-- add color (you can make it the exact same color using the Dropper tool :tool_dropper: )
-- zoom back out and admire your blood cell

If the document is too heavy (I don't know what else you plan to put in it), later you can use Path menu > Simplify to reduce the number of nodes. Why place so many to begin with? Because you can make the vector path fit very, very closely to the image. Simplify, if clicked only once, will only reduce the number of nodes. (If you click a 2nd time, it will distort the path. So only click once.)

Good luck :D

mmohaqeqf
Posts: 3
Joined: Sun Feb 28, 2016 8:05 am

Re: Bi-concanve

Postby mmohaqeqf » Sun Feb 28, 2016 9:18 am

Thanks for the reply;
I will try to do it to see what comes out . . .
But, is there anyway to draw half of the image and do a mirror operation?
Thanks

tylerdurden
Posts: 2344
Joined: Sun Apr 14, 2013 12:04 pm
Location: Michigan, USA

Re: Bi-concanve

Postby tylerdurden » Sun Feb 28, 2016 11:30 am

mmohaqeqf wrote:... is there anyway to draw half of the image and do a mirror operation?


I'd make a clone and flip it, snap the bounding boxes together.
Image
Have a nice day.

I'm using Inkscape 0.92.2 (5c3e80d, 2017-08-06), 64 bit win8.1

The Inkscape manual has lots of helpful info! http://tavmjong.free.fr/INKSCAPE/MANUAL/html/

mmohaqeqf
Posts: 3
Joined: Sun Feb 28, 2016 8:05 am

Re: Bi-concanve

Postby mmohaqeqf » Sun Feb 28, 2016 12:49 pm

Thanks.
I will keep posting my questions as I go along !

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brynn
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Joined: Wed Sep 26, 2007 4:34 pm
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Re: Bi-concanve

Postby brynn » Sun Feb 28, 2016 1:12 pm

Regarding the clone idea (which is a good idea) -- I'm not sure how realistic you need the drawing to be. But I'm just wondering if blood cells would be perfectly symmetrical. Yes, they're generally symmetrical. But precisely, I'm not sure.

Maybe that much detail doesn't matter?

tylerdurden
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Joined: Sun Apr 14, 2013 12:04 pm
Location: Michigan, USA

Re: Bi-concanve

Postby tylerdurden » Mon Feb 29, 2016 5:17 am

More for timesaving methinks.

It's pretty common in CAD to use mirroring when possible to speed up sketching and modeling.
Have a nice day.

I'm using Inkscape 0.92.2 (5c3e80d, 2017-08-06), 64 bit win8.1

The Inkscape manual has lots of helpful info! http://tavmjong.free.fr/INKSCAPE/MANUAL/html/

Lazur
Posts: 4717
Joined: Tue Jun 14, 2016 10:38 am

Re: Bi-concanve

Postby Lazur » Tue Mar 01, 2016 9:17 am

tylerdurden wrote:Image


Offtopic: can you tell me which program you use to screencapture to gif? Had no luck with the ones I tried. (Not recording, recording 50 frames only, not installing because requires refreshing to outdated dotnet framework, records but crashes when capturing filter editing, records but doesn't let you use the Ctrl key while drawing with inkscape...)

tylerdurden
Posts: 2344
Joined: Sun Apr 14, 2013 12:04 pm
Location: Michigan, USA

Re: Bi-concanve

Postby tylerdurden » Tue Mar 01, 2016 11:41 am

Lazur URH wrote:Offtopic: can you tell me which program you use to screencapture to gif? Had no luck with the ones I tried. (Not recording, recording 50 frames only, not installing because requires refreshing to outdated dotnet framework, records but crashes when capturing filter editing, records but doesn't let you use the Ctrl key while drawing with inkscape...)


I'm using Sharex 9.6.1

Saves pics, videos using ffmpeg or anim gifs, automatic processing and upload to sharing sites.

Their main site (getsharex.com) is sometimes flakey. I can't reach it right now.

https://github.com/ShareX/ShareX/releases/tag/v10.7.0
Have a nice day.

I'm using Inkscape 0.92.2 (5c3e80d, 2017-08-06), 64 bit win8.1

The Inkscape manual has lots of helpful info! http://tavmjong.free.fr/INKSCAPE/MANUAL/html/

Lazur
Posts: 4717
Joined: Tue Jun 14, 2016 10:38 am

Re: Bi-concanve

Postby Lazur » Tue Mar 01, 2016 4:23 pm

Thank's!


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