[WIP] Please critique the continental landforms

[Master TMO]

I've come up with another script idea to test out. This world started out as a standard Fractal Terrains 3 randomly generated map, with no manual tweaking. The script is an attempt to fix FT's normal result of continents with central mountain ranges.

Please take a look at this and see if the landmasses look reasonably plausible. There has been no manual modifications made, all with scripts and standard menu options (and a simple selection modification in Photoshop). Please feel free to point out anything you think doesn't look realistic. I freely admit that there was no attempt to define continental plates. I have no doubt there are plenty of issues with it.



Thanks in advance for any feedback.

[Master TMO]

Hmm... Apparently, while we have a very active River Police Squad, we have yet to develop a Continent Police Squad.

For my own critique, I think that, due to the way the script runs, the mountain ranges enclose too much of the continents. They tend to go all the way around the edge, rather than being just on 1 or 2 sides of it.

[bartmoss]

The continent looks good for a random script, but I don't buy it as "this could be earth". You are right, the continents are too "enclosed" by mountain ranges.

[Master TMO]

A couple of modifications to the script, and it looks much better. I am not sure if it has reached 'believable' levels yet though...

Feedback would be most welcome. What looks wrong about it? Much obliged!

I can see it still has some issues with areas where the inland lakes had been, but those are okay. Fixing those wasn't the primary goal of the script. More believable mountain ranges was.

[Master TMO]

This version is probably easier to see the various elevations. It does not have the editing the color map above does - no incise flow, filling basins (multiple times), smoothing (multiple multiple times), and rivers. This is the map just after the script finishes.


And, for comparison, here is the original base map, with no changes. I am flipping back and forth between the two, and can't quite decide if I'm happy with how it works, or disappointed it didn't do more.


I should probably run it through more paces before deciding. Bounce it against a few more random worlds, see if it works right or not.

(PS - It's a good thing I previewed the post before submitting... the images were in the wrong order. )

[Lukc]

Well, you have the classic problem of fractal terrains - they don't look like there have been plate tectonics going on. Otherwise they look ok, if'n you're asking me

If you want plate tectonics, though ... different kettle of phish.

[Master TMO]

I was aiming for a way to get at least closer to a semi-plausible layout, from fractal to plate. What the script does is play with the roughness factor, starting low from the coast and rising upward to a peak, and then lowering again back to the low. The idea was that it would put the mountain ranges at the edges, and plains in the center. The first script took that too literally, and you can see the mountain ranges completely enclosing the continents on all sides. The second script is actually almost exactly the same as the first, but the starting selection is changed, so that it is related to the shape of the landmasses, but not identical, throwing the edges off-kilter enough so that it isn't obvious what's going on.

Some of the good points of this second version are visible up north: a lot of the land got flattened out, and in the upper left is an isolated straight mountain range. There are also a couple of other areas where the ranges were separated from the main mountain range.

You can see a few rifts in the sea bed where the script operated. I don't worry about making the sea bed realistic, so I consider those an acceptable side-effect of Progress.

Also, I just realized that the selection I used for this run did not have the lakes taken out of it, so it technically wasn't quite correct. I've run it again, and this time am running a fill basins to get rid of the visual confusion of those lakes. I won't do a full production on it though, just enough to clear it out and make it easier to see how it is.

And I do appreciate y'all putting up with me and my continual experimentation. Most of them don't turn out the way I want, but I figure if it was that easy, someone would have done it a long time ago.

[atpollard]

The continents lack a center. Earth's examples ... North America, South America, Africa, Australia, Asia, Europe and Antarctica ... all have a distinct 'center' around which you can draw a circle or ellipse and select most of the area of the continent. Sure bits and points stick out, but there is a distinct, roughly round 'center'.

North America: centered on the Great Plains.
South America: the Amazon bulge in the north.
Africa: The northern bulge centered on the southern Sahara.
Europe: Centered on the German-Swiss border.
... you get the idea.

Your continents are too 'stringy' - more like large irregular islands - with too many internal areas lower than sea level. (The number of places below sea level - excluding the oceans - is staggeringly few on the real Earth.)

Once you have a central continental mass, Earth seems to have mountains around one or more edges of that mass - almost at random how many sides have mountains. One algorithm for all continents (without some randomization factor) will probably have limited success at creating 'realistic' continents.

I hope that this helps.
Arthur

[Master TMO]

It does help, thanks. Part of the cleaning up process on a world involves filling in all those interior seas, but I just hadn't put that work into those particular maps. Doing so won't really fix the issue you point out, of course. But it will look a tiny bit better.

[Master TMO]

Ah, just realized an issue with the color scheme I used in those images, that is probably confusing things - the altitude color scale is relative. White is the highest altitude on the surface. Whether it's 32000 feet, or 10000 feet. So two different maps will have most likely have the same elevation shown as two different colors.