A question was asked on whether my selection blend script could be made to blend arbitrarily... The answer was no, but this new script goes where no one has gone before in terms of sheer slow performance, mind-numbing lack of feedback, and moderately interesting results.

Get it here: http://silent9.com/incoming/sc ... _blend.scm

It registers under Filters->Render->Path Blend.

You have to select two paths (they must be different, and the script only looks at the first segment of compound paths) and one gradient. The script finds the shorter path, and walks it 1px at a time, and creates a selection between that and the correspond point of the longer path.

A variety of results:


Upper left: Full saturation gradient between a path and an enlarged duplicate of itself.
Upper Right: Some terrain gradient between two random path squiggles
Lower Left: A transparent gradient ("Neon Cyan") between two random path squigles
Lower Right: A partially transparent gradient ("Flare Radial 101") between overlapping paths.

The interesting effects come with transparent or partially transparent gradients. Here is an example with one called (appropriately) "Red Tube (which took a good 5 minutes to run on my machine):


Have fun (and patience!)

-Rob A>

wow, that one I am going to grab, patience might be the stickler.

Thanks Rob

Another quick example using a spiral path imported from inkscape that was rotated and scaled to make the second path... then added a quick drop shadow...



-Rob A>

Indeed. WrapMap is dwarfed .

This script is Great! Aspesially since I can make very accurate blends using the sample along a path script to use with it. I'm going to try and blend two paths on one side of an O ring and two on the other.

Better than Illustrator blends.

Nice script RobA!

Alan

I have always wanted to be able to do this.



I made this with two paths blended with a straight FG to BG color and then used the curves on the blend to make it ridged in the middle. Then I got the taper by drawing with the airbrush tool set to use color from gradient and a layer mask around it on its own layer. I set the masked blend layer mode to screen to taper the blend layer below it. If the point was black then it would be raised all the way up in the 3D preview. Dark pixels are high and light ones low when working with these height maps.

It felt like Christmas when I saw the details of this script. I will definetely use it a lot.

In 3D software it would take some know how to do this usign rails etc.

Alan

Very nice Rob thanks!

I was lazy

But you made me pull out the maths:


So I could have it calculate the point along a line closest to another point - i.e. the perpendicular intersect. I'm sure there are fancier ways to do this, but mine worked so I've left it

Here is your sample:


Of course, each blend section is the length of the ratio of the two lines, so if they get an order of magnitude or more different you can see the flats in the blended segments.

The linked file has been updated - you may need to refresh your browser to get the latest one.

-Rob A>

Looks perfect now

Another small update:

-Reversing the path selection reverses the direction of the blend.
-I've exposed the overlap parameter as a slider, as this might be useful to adjust when dealing with transparent gradients to minimize banding effects.

-Rob A>

It's been way too long since I've seen math like this and believe it or not, I enjoyed doing it in the day, but now, I'm happy to say it's all but a dream to me now. lol

Glad you shared that though Rob; brought back a lot of memories.

2nd try (not showing first) using your Script-fu Rob. The only issue I see in the scan like lines at only one point in the render; happened with the other render too with a different gradient). Not sure why it is; it might have something to do with GIMP 2.8 rc1 64-bit, but not sure. For this one, it's just one circular selection turned into path and a smaller one doing the same.

Mainly because turning a circular selection into a path makes a bad circular path

Here is the same thing using two circular paths from inkscape:


There is still a seam at the join however - it is an artifact from making two selection butted up against each other having the same end points. You see the background bleeding through the join. It is reduced if the start/end of the paths are not horizontal or vertical to each other (different gradient, btw):


-Rob A>

That's cool Rob; thanks for the explanation; not hard to clean of course, but just curious to know.

Might as well do something with the ring I made earlier. Erisian might like this one.

Created a seamless interlinked texture and used Droste for the result.

Very nice results with this script!

Thanks for the updated script Rob. As always nice results.

Wow! I think this may be useful to draw ribbons:
viewtopic.php?f=8&t=3089&start=0

I'll keep trying because I can not find how to use this script

Fun stuff using scaled copies of paths:


.... And one more update to the script (same download location)...

It now will support paths with multiple segments, so long as the two paths have the same number of segments. This works particularly well with transparent gradients. Here I turned text to a path and then copies, scaled and translated the path to get a second version to blend to:


-Rob A>

That result looks cool Rob.