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ofn-brush-strokes-on-path - Ofnuts - 04-13-2021

Adding an animation feature (each brush stroke on its own layer). Ending up being a major rewrite. Still have to update the doc before releasing in the wild.

[attachment=5859]

For the above:

  • Find a Brush with foot steps (brush hose, alternating each foot)
  • Create a circular path
  • Apply the script to generate 30 strokes on a transparent background
  • Duplicate the image, shift the layers by one (top layer to bottom of stack)
  • Do that two more times, to have 3 images that are 1/2/3 steps behind
  • Use ofn-interleave-layers to combine them with 75%, 50% and 25% opacity to the first one
  • Export as (slow) animation


RE: ofn-brush-strokes-on-path - Krikor - 04-14-2021

[Image: KNwst97.gif]

RE: ofn-brush-strokes-on-path - Ofnuts - 04-14-2021

I can't work on the doc if I spend my time answering questions about distributing the stuff Smile

RE: ofn-brush-strokes-on-path - Ofnuts - 04-18-2021

New version available at the usual place.

RE: ofn-brush-strokes-on-path - Krikor - 04-19-2021

The plug-in has preserved its previous functionality and has gained fantastic versatility!

This fading effect was great!
Ofnuts, thx!

[Image: LGM0lQ7.gif]
In order to use a content or a part of it, you must attribute it to macrovector / Freepik, so we will be able to continue creating new graphic resources every day. -  Designed by macrovector / Freepik

RE: ofn-brush-strokes-on-path - denzjos - 04-22-2021

Ofnuts, 'ofn-brush-strokes-on-path', a nice script. Two problems : if I animate a scene in gimp, then the moving object is perfect blending out. When I export the animation to a gif file, then the blending out disappeard. What am I doing wrong in the workflow ? Second problem : how can I use a background (picture or photo) in the animation? I just can choose between white, background(colour), foreground(colour), pattern and transparent. I tried some things but I can't figure out how to do it. Thanks in advance for the answer.
The exported gif file :
[attachment=5895]
As seen in the animation in gimp:
[attachment=5898]
Gif export settings I used :
[attachment=5897]

RE: ofn-brush-strokes-on-path - rich2005 - 04-22-2021

Quote:Second problem : how can I use a background (picture or photo) in the animation?

This first: Make your animation as a RGB sequence. There are plugins / scripts that will add a background image to each layer. Ofnuts has one that works with RGB mode.   http://sourceforge.net/projects/gimp-tools/files/scripts/ ofn-interleave-layers.zip (dated 2020-04-25)

You are probably better off using Ofnuts plugin in RGB mode but there is an alternative (works with indexed as well) is Saul Goodes script http://chiselapp.com/user/saulgoode/repository/script-fu/wiki?name=sg-combine-bg

Quote:if I animate a scene in gimp, then the moving object is perfect blending out. When I export the animation to a gif file, then the blending out disappeard.

Why the first quest last ? Transparency in an indexed image is binary, either on or off. To get a fade out (using layers of deceasing opacity). First convert the image to indexed Image -> Mode -> Indexed  using the dithering option. 

[attachment=5899]

Then you can add a background using Saul Goodes script and finaly export as an animated gif.

[attachment=5900]

RE: ofn-brush-strokes-on-path - denzjos - 04-22-2021

Thank you rich for the reply. I'll try it out.

RE: ofn-brush-strokes-on-path - Ofnuts - 04-22-2021

(04-22-2021, 09:11 AM)denzjos Wrote: Ofnuts, 'ofn-brush-strokes-on-path', a nice script. Two problems : if I animate a scene in gimp, then the moving object is perfect blending out. When I export the animation to a gif file, then the blending out disappeard. What am I doing wrong in the workflow ? Second problem : how can I use a background (picture or photo) in the animation? I just can choose between white, background(colour), foreground(colour), pattern and transparent. I tried some things but I can't figure out how to do it. Thanks in advance for the answer.
The exported gif file :

As seen in the animation in gimp:

Gif export settings I used :

In a GIF (and the color-indexed mode in Gimp) the opacity of pixels in layers/frames is binary so anything under 50% becomes transparent when you export to GIF.

In my own animations, I do the animation in RGB mode, and the object and its fading copies are put on a fully opaque background so all layers are fully opaque when I create the GIF. This isn't much of a problems because  in my animation the layers are in a solid color almost everywhere so they compress well. Over a real picture, I would expect Filters ➤ Animation ➤ Optimize (for GIF) to be quite efficient.

Technically, for a 3-steps fade:

  1. Create the N frames  of the animation, with fully opaque object on transparent background (stack image)
  2. Use  ofn-interleave-layers to copy the frames of Stack at 100% opacity over a solid background, yielding  Image1
  3. In Stack, move the top layer to the bottom
  4. Use ofn-interleave-layers to copy the frames of Stack at 75% opacity over the frames in Image1, yielding Image2. Image1 can be discarded.
  5. In Stack, move the top layer to the bottom
  6. Use ofn-interleave-layers to copy the frames of Stack at 50% opacity over the frames in Image2, yielding Image3. Image2 can be discarded.
  7. In Stack, move the top layer to the bottom
  8. Use ofn-interleave-layers to copy the frames of Stack at 25% opacity over the frames in Image3, yielding Image4. Image3 can be discarded.
  9. Export Image4 as your animation.


RE: ofn-brush-strokes-on-path - denzjos - 04-22-2021

Thanks Ofnuts for the reply. seems to be some work but when I have some free time, I'll give it a try.