Rheia: one final try at ground-up worldbuilding

[Tiluchi]

Hi all!

This isn't my first started thread here, and most of my other posts have been similar projects: working on worlds from plate tectonics on up, in order to have a reasonably realistic world geography. Have started this twice before here and stopped both times due to not being satisfied with the general realism of the world's geology or the direction it was going. Nikolai Hersvelt's amazing posts over at Worldbuilding Pasta were enough to get me to give it another try with the new tools that are available, and I've finally progressed far enough to be much happier with where this is going in terms of aesthetics and realism. Figured I would post my progress here in case the workflow is useful to others considering similar projects.

Previous attempts started with a present-day world map, and working backwards with plate tectonics to get something reasonably plausible. This works as far as it goes, but I found it difficult to justify present-day positions of continents and plate boundaries with any kind of detailed history. After a fair amount of frustration with that I turned to the Worldbuilding Pasta tutorial, constructing a complete geological history of a world for about 800 million years until the present day. That worked better from a realism standpoint, but it presented the opposite problem for me: starting that early means the world tends to take on a mind of its own, and I ended up with a final geography that I wasn't particularly satisfied with (unfortunately, I only realized this after almost a year of working on tectonics and then topography). For those who are somewhat agnostic about the final geography and/or don't care as much about realistic biogeography, this is probably still the best way to go.

Ultimately I ended up going with a little bit of a hybrid approach: I made a very, very basic sketch of how I hoped things would look in the present day, then did a GPlates history going back about 400 million years. I chose this for two reasons: first, because tectonic events older than this generally have little to no influence on present-day topography, meaning that I could still feel pretty confident about realism. Second, because this means only going through one supercontinent cycle, allowing me more control over the final geography while still giving lots of geological detail. It also allowed me to get even more detailed with things like terranes and microcontinents than the Worldbuilding Pasta example, close to how things worked on Earth. (note also that our understanding of Earth's plate movements older than 400 million years ago is sketchy at best, so I wasn't too worried about losing important details)

A gif of the last 420 million years of plate tectonics is below (sadly compressed to all hell to make it a small enough file for the CG site). I'm lazy and technologically inept so this is just a screengrab from GPlates, without a tracker of the number of years- just know that it starts at 420mya and ends at the present day.

Attachment 133542



A few weeks of work on plate tectonics leaves me with the present-day map below. The little empty polygons in the middle of continents are cratons, black is active continental orogenies, orange is active volcanic orogenies (my worldbuilding requires distinguishing between igneous and sedimentary rocks in the present day), grey and yellow are former orogenies, purple is large igneous provinces, and light blue is oceanic plateaus. Obviously these are just guidelines (and the "continents" are actually continental shelf rather than dry land), and I still have a fair amount of leeway for making coastlines and topography for my liking.



Currently I'm working on the topography of the world. It's probably not an entirely rational decision, but I'm opting for hand-drawing contour lines in Illustrator, rather than using Wilbur. I may force myself to learn Wilbur (the work of Harrg and MrBragg on here, among others, is inspiring), but for the world map I'd rather have control over the topography and placement of rivers myself, and have a vector-based world map that I can change or add details to later as I work on world history and other things. I'm also using Mac and suspect my work PC would just dissolve into a puddle of acid if I tried to use Wilbur on it.

Posting here my current progress, with two major continents finished and four more to go, plus most of the islands. It's a much-reduced PNG version of my 16000 x 8000 Illustrator image. I probably won't put quite as much detail into the other continents as I have into the largest one here, mostly because I know Lightroom has a tendency to crash when a file just as too many objects. I also expect there will be some minor-to-medium changes after I have a first draft of worldwide coastlines and elevation, and once I've finished climates and have a better idea of precipitation, currents, and erosion.



Comments and critiques of the geology and what I have so far of the topography are much welcomed!