This gruesome effect was created by running the following:

G'MIC>patterns>lava
New layer flood filled pink in colour mode
Flatten image
G'MIC >Light and shadow>Relief light
Grain Merge layer for the blood

No problem for me, because I usually have dinner very late!

Well, I consider the result very realistic and evocative of human flesh, but at the same time not as disgusting as I imagined before looking at the thread. I also like the fact that such an effect can be obtained in a pretty simple way.

Thanks for sharing this method, I will surely test it.

Wow Erisian, I wonder where you got your inspiration?

I like it. It has a certain charm.

It has charm alright....Anyway, very interesting Eris. I think it would make a good pattern for text or something along that line.
I hope none of us have innards like that.

erisian: eeuugh! looks like something from x-files...

I had a gut feeling that's what you used.

Okay, here is the result I got by following this interesting tutorial:



In more detail, when running the mentioned G'MIC filters over a white layer, I left all the options of "Lava" at their default, whereas the only settings of "Relief light" that I changed (relative to the default values) are "Ambient lightness", "Darkness" and "Image smoothness", setting them to 1.00, 0.20 and 1.00 respectively.
In order to depict the blood stains, I created a new layer that I filled with a dark red hue and equipped with a layer mask, to which I applied the "Solid Noise" filter and then the "Equalize" command.

@Erisian: the blood stains appearing in your illustration look much more lifelike than those I attempted to represent in my example. So, how did you manage to generate them?

Very nice result!
Reminds me to Molten Material script, with whom I enjoyed some time ago and I have obtained interesting textures:
https://registry.gimp.org/node/13948

when you just use the lava without any colour-overlay, it has a certain fiery-golden resemblance

What fun, Erisian! How gutsy.

gold in crude oil

very good erisian - can't say I know by looking at it how real it looks. I have been fortunate/unfortunate? enough not to see someone's insides.

Good job on the gold on oil esper.

Yours is a prettier colour Gino d.

Odin - actually it was an accident but I did think of that at the time.

Gino D - I used a texture brush for the blood. Grain merge tends to brighten colours so you need to use a darker red. Good result you got though. I played with the same sliders as well.

YAFU - I remember that script. I'm sure I must have it somewhere.

Esper - Nice work. I'm sure imagination could find a lot of uses for this.

Molly - I'll have a go at some text and see what turns up.

Thank you all for commenting.

Thanks for the useful indications.

am i the only one who gets nothing but spaghetti or larvae in the lava filter? what pictures do you guys start from? no matter what i change in the settings or what picture i have started out with i only get spaghetti (= long, white lines, more or less tangled up) or larvae (short, white lines, more or less tangled up), with far too little red, yellow and orange around it. if i use the relief light on it i get no real effect out of it because all the areas that get highlighted were white lines anyway. this is extremely irritating and i demand to know why erisian, gino d and esper all get nice looking lava when i don't!

esper: those are great! i think you're probably the only one here on gc who would start out with slime and gore and end up with nice text effects .

its amazing, isnt it

will try some more and then make a tutorial, i guess

about your spaghetti and larva problem:
i couldnt get it to work at first too, then i found out, the crucial part is really the 'Image smoothness' in the Relief Light filter
that is what gives you the 3D effect

esper: but it's the lava filter that gives me the spaghetti or larvae, i can work the relief light filter well enough. i want better looking lava and i want it now!

oh, im sorry i misread that

can you post a screenshot ?

okay, here's the larvae in two sizes. i get this no matter what i change in the settings. or spaghetti, which looks just the same only the lines are longer.
to get the real innards texture i think i need much more space between the white lines. and to use it as a text effect i would need a lot more areas with colour.