If not, how was this done? Just curious.

Maybe can be approximated that way, but this one really feels like someone sprayed the organic roots onto this couple.

Looks like it must be a custom made texture?

Almost certainly a 3D render.
The author describes his work as: "(3d digital image/rendering - animation, digital sculpture, digital video, new media)" on his website.

Refs:
http://deignis.deviantart.com/art/Last-kiss-258460174
http://adamakis.blogspot.com/
http://adamakis.blogspot.com/2011/09/last-kiss.html

If you want to have a go at something like that, I'd say the first step is to get together some good 2D textures to work with (on transparent backgrounds of course). Then try various 3D mapping apps. But you would also need a good 3D wireframe model.

Thanks for the links jontait2. Should have done some sleuthing to find his work on my own. lol

Still, was hoping it could be somehow done via GIMP, but I suppose, if so, not so easily. I did toy with a few G'MIC presets and such, but not happy with those results (so thus not sharing).

@Lyle:
http://deignis.deviantart.com/art/Last- ... 0#comments
In reply to the second comment (at the end of that thread), the author says he used "3ds max and ivy plugin"
So it looks like the texture was actually generated (rather than natural) just using the ivy plugin, presumably with null foliage.

Interestingly, that ivy plugin for 3ds max is based upon Thomas Luft's Ivy Generator which is GNU GPL-licenced - so it may be worth investigating ..the generator output can apparently be used in Blender.

It would be cool if such a plugin was available in the GIMP using vector paths to follow. I can request can't I? lol

Thanks for the additional info jontait2.

Well, if you have the time, you could download the binary for that ivy generator, have a play with it, find out a bit more about the file output formats and whether they really can be used in Blender.

I've toyed with it, but have no clue how to use 3D programs. lol

Ivy Generator was one of my favourite tools in Windows. Thanks for reminding me about it. I didn't realise there is a Linux version.

Shortlived joy . I have to compile it. Spoke too soon, it has an executable after all.

@Lyle:
The generator imports/exports .obj and associated .mtl files.
Basically .obj (object) = wireframe; .mtl (material) = texture
So the .obj file defines the polyhedral vertices of the object(s) to be rendered and the .mtl file(s) define the texture to be mapped onto the faces of that/those polyhedra
Both file types are plain text files and so can be examined with a plain text editor (eg. Notepad++ on Windows)
Refs:
https://en.wikipedia.org/wiki/Wavefront_.obj_file
http://paulbourke.net/dataformats/mtl/

I think the general idea is that you first create a 3D scene in some 3D image maker such as Blender, export that as obj+mtl, import to the Ivy Generator, set the growth parameters so that the ivy starts growing "naturally" across your 3D scene from some specified starting position and, when it's gone far enough, export as obj+mtl again and re-import to Blender or some other program for final render.

So, to emulate Adam Martinakis' superb work, I think you first need to find settings for the growth parameters in the Ivy Generator to generate something like the leafless ramification seen in that render - presumably by setting leaf size to zero (?)
If that is successful, you could move on to trying some simple shapes such as a cube and/or sphere - create a scene in Blender first, containing the shapes, import the obj+mtl to Ivy Generator and see if you can (partially) cover the shape(s) with the leafless ramification. If you can get that far, then you might start thinking about more complex forms such as bodies/faces.

Yeah; exported an STL file from Sculpture Generator and was able to export an obj file via a cool Win10 app and import it into Ivy Generator, but the outputted OBJ file from Ivy Generator wouldn't open in the Win10 app. Maybe if I outputted an MTL file it would open in the Win10 app; will try that later. Thanks again for the addition info.

Ivy Generator Linux version is buggy. Ended up using windows version in wine. Then Blender version import broken so upgraded Blender to latest version. Seems to be working now.

As the saying goes "Here's one I did earlier". About 4 years ago in W2K. I had to manually attach the textures as Blender couldn't read the MTL file. It only has a sun for lighting.

Lyle possibly an animated brush along a path on separate layers would work for you?

Yes; done similiar things in the past when rendering ivy on walls. Still, always am keeping an eye out for a more automated (lazy) way. lol