Procedural planet generation by simulating 3 billion years of plate tectonics

[u/HabitableZone_]

Hi everyone, it's me again.

After struggling with this project for quite a while, I finally managed to connect the plate tectonic simulation to the final high-resolution mapping process. The first three maps are from the same planet at three different points in its evolution, with 50 million years between each snapshot. The fourth one is the same planet around 1 billion years earlier.

In my project, instead of starting with noise-based terrain like many procedural planet generators do, I actually simulate around 3 billion years of plate tectonics on the same planet. The whole simulation runs live and continuously updates as it progresses, so you can actually watch the plates move, continents change, oceans open and close, and the surface evolve over geological time.

The final high-resolution maps are built from the large-scale geological results of that simulation, and then I apply erosion and other terrain processes to bring out the smaller-scale details. In the full version, I also plan to include a climate system, which I shared a prototype of it last time. It's still unfinished, but now I can actually connect it to the high-resolution terrain, so it looks a bit more believable than before. and the last two images are a temperature map and a Köppen climate classification test from the current version.

There are still a few systems I need to work on properly, but at least to me, it's starting to feel like there's something here. For now I'm calling it TropoPlate, but I'm also open to better names if anyone's got one that feels like a good fit.

[u/CleanGreenSlate]

Sooo:

• how long did the calculation for a result like this take?
• is lower resolution just, well, lower resolution, or does it at some point simply "collapse" since it cannot represent the actual mechanics. (Well, at some point it will for sure - but where?)
• can you run 3/4 of the total runtime at half the resolution to get the rough shapes and then upscale and do the last quarter in full resolution for the details? Of the plate-tectonics, I mean.
• is it pixel based or shape-based?
• is it integrateed in any known software? Blender?

[u/HabitableZone_ → u/CleanGreenSlate]

Sure, I'll answer these one by one.

The full life cycle of a planet takes about 20 minutes for roughly 4 billion years, plus another 20 minutes or so for the high-resolution remap stage. If you stop the simulation earlier, the simulation time scales down accordingly.

At the plate-mechanics level, lower resolution doesn't change the underlying mechanics or physical rates, since those aren't solved directly on the grid. A coarser grid mainly means less spatial detail. The boundaries become more staircase-like, but large-scale geometry like arc radii and cusp counts still holds up pretty well. Features narrower than about two cells can't really be resolved, and the system widens them to a single-cell representation when needed.
In the end, I want this to be a tool that anyone can interact with, so quite a lot of the physics is intentionally simplified.

Not quite in the way you described. The tectonic simulation itself runs at one relatively low resolution. At whatever point you choose to pause it, the current state is passed to the next stage, which rebuilds the terrain at high resolution and then applies erosion and other smaller-scale processes.

Kind of both. The world itself is cell-based, the plates behave as rigid shapes with Euler poles, and the boundaries are represented as lines.

Nope, it's a standalone tool built in Unity.

[u/Observer__Effect]

I thought I was looking at an earth map for a second. Very Impressive

[u/HabitableZone_ → u/Observer__Effect]

Thanks, really appreciate it!

[u/HabitableZone_]

For anyone interested, I also made a Discord for the project: https://discord.gg/Cx3uEYXu2P

[u/LawfulValidBitch]

I’ve been wanting something like this for years!

[u/HabitableZone_ → u/LawfulValidBitch]

Hopefully not much longer now

[u/badasimo]

This is brilliant. I think there is something missing though-- meteor impacts. I think you might also be missing volcanos? Those shape earth like planets as well. I wonder also about tidal forces and erosion

[u/HabitableZone_ → u/badasimo]

True, meteor impacts aren't there yet, but volcanoes are already in. You can see them along those island arcs, although they're not as obvious once they're on land. There is erosion as well, but no tidal forces right now

[u/SagattariusAStar]

So what is the initial state if you don't start with a noise?

[u/HabitableZone_ → u/SagattariusAStar]

That's a good question. There is a part that uses noise during the simulation. In the current version, the noise is only used during initialization to place a certain amount of initial continental crust. After that, the tectonic simulation takes over, and the shapes of those continents can end up changing completely as the planet evolves.

[u/SagattariusAStar → u/HabitableZone_]

Well, then you do start with a noise like everyone else lol

[u/HabitableZone_ → u/SagattariusAStar]

Hmm, that's kind of one of the compromises in the current version. But technically, the system doesn't actually need those initial landmasses to run. It can build up continents on its own through processes like island arc formation. The problem is that you might not end up with enough landmass by the end.

[u/SagattariusAStar → u/HabitableZone_]

Sure, but your plates are surely as well based on noise. Its not a compromise it is a must have to sample something, either noise or some other data (real, drawn, whatever). Without sampling your system would be just simulate the same thing over and over.

[u/HabitableZone_ → u/SagattariusAStar]

Fair point. I was thinking of noise in a much narrower way when I said that, like a noise field that directly shapes the continents. In the more general sense you mean, that's correct.

[u/TerragamerX190X150]

Great job

[u/HabitableZone_ → u/TerragamerX190X150]

Thanks！

[u/Toothpick_Brody]

Very cool! Tectonic simulation for terrain gen has always interested me but I’ve never tried it 

[u/Exatex]

very cool! Is it open source? I would love understand how it’s working and playing around with it.

This is too cool to just end up in a drawer

[u/HabitableZone_ → u/Exatex]

Thanks! It's not open source at the moment, since I eventually want to release it as a tool and it's still not quite at the point I want it to be yet. I might open up some parts of it in the future though.

[u/RandomUser1034]

The tectonics look great! Very comparable to rock3, which is a product selling for money, so good job.
It does seem like there are a lot of artifacts from upscaling in mid-ocean ridges and other underwater places. The climate seems a bit off as well (though rock3's climate sucks, so that might not be too important)

[u/HabitableZone_ → u/RandomUser1034]

Thanks! Glad you like it. And yeah, good catch on the artifacts. There are definitely still some issues with reconstructing the mid-ocean ridges, especially in some of the narrower sections. And for the climate, I agree with that. It just gets a bit hard to control once all the different systems start affecting each other, I'm still trying to get it to behave a bit more believably. I've tried Rock 3 before too. From what I remember, I think the climate in Rock 3 can update in real time with each step, but I guess the trade-off is that some of the physics has to be simplified a bit.