Push away existing terrain through displacement

I’m working on a heightmap for a game with various islands and continents.
My goal is to create a second heightmap, that is based on the first one, but contains various tectonic shifts (well the appearance of that), including shifting and pushing and squeezing various landmasses.

I toyed around for a bit with the displacement tool, but I don’t quite understand how it works.
While of course there’s gonna be a need to go over the finishing touches by hand, I really figure the displacement tool could somehow achieve this.
But I’m far from married to using that tool, any way I could achieve this would work for me.

Also, here’s a sketch with the general idea I made in PS using distortion filters.

Hey, what you are trying to achieve is in fact possible with displacement, however, it is not an easy feat, as the Displacement device will move all of your terrain. It does have a mask option, however, that is a “post FX” mask, meaning it does not determine what parts of your terrain get displaced, it only determines what parts of the overall displaced terrain, should be blended with the original terrain.

So, how do you overcome that issue? “Simple”, you displace the mask as well! See below:

Now, this is a very, very crude approach, and a much more refined approach would be to, for example, create the islands separately (this is more resource intensive, as you would have to duplicate the processing for each additional island), but it shows this can be done.

Important to note, displacement often introduces (a lot of) artefacts. One way to remedy this, is to do “serial displacement”/“stepwise displacement”/“simulation distortion”, different words for the same, namely using multiple Displacement devices in succession. Doing so, you can make small, incremental displacements at each step, which reduces artefacts (although they are still there), and gives you a finer control.

Please let me know if this helped you, or if you want me to clarify some more!

The tmd:
island-tectonic-shift-emulation.tmd (244.6 KB)


I’ve got good news and bad news:
Bad news: Thanks for giving a try to help me out. Unfortunately that’s not really what I’m looking for. Your example is purely the displacement, but keeping the shape of the “islands” the same. It’s like just cut and pasting the islands a bit to the left/right.

Good news: Testing this, I gave it another try trying to figure out how the displacer works and potential workarounds, including your suggested “multiple smaller displacements”. One thing I did was trying to figure out the “Use Transform Input” mode of the displacer works, especially what the top input wants. Thankfully in modern World Machine, if you pull an input and release in open space, it opens a window of potential input suggestions. And this included the Distortion macro. And with that and fiddling with values, it gave me basically exactly what I’m looking for.

This is just my testing sandbox of a low-resolution Earth map, but basically exactly what I’m looking for.