November/December 2024 Challenge: The archipelago of endless wrecks

[Diamond]

Well, it looks pretty good so far. I think if you can get the bathymetry right, this will kick a$$.

[Redrobes]

I had another go at that and I don't think its going to happen. The issue is an old perennial one in that in order to get the bathymetry right it needs the sea bed raised and to do that means getting the undersea height to within a few m or 10's of m from the surface. If I break through the surface then it changes the coastline. Its so much easier to start with a 3D landscape and mess about with it as required and then at the end you have whatever coastline it gives for sea level. Trying to do this where you are setting the sea level coastline and trying to figure out the above sea level and below sea level relief to make that sensible is almost impossible.

I have been running the erosion passes and that in itself alters the landscape and changes the shape of the coastline too. A further complication is that because I created the relief from blurs and so on then its a bit blobby. I am finding that there are multiple lakes and spots which are highly unrealistic even with a sort of basin fill. That and my erosion app is a total pain to operate. Its like fitting a saddle to a velociraptor. On the one hand its quite powerful but one false move and it will eat you alive. Its good at generating deserts and flooded terraforms which look nothing like what you wanted from it.

I think I will bin my latest attempts to mess with the bathymetry and go back to where the last images here showed. Perhaps its best if I render it as an atlas style and not worry about the 3D effect of it so much. I'll keep going for a bit and see if leads to a dead end or not.

[Chashio]

Interesting progress. The process sounds almost more painful than doing it by hand, but the results have a nice look to them.

[Diamond]

I would pay a large amount of money to watch RedRobes saddle a velociraptor.

[Greason Wolfe]

I would pay a large amount of money to watch RedRobes saddle a velociraptor.

As would I.

Also, digging the effort and approach.

[Redrobes]

Interesting progress. The process sounds almost more painful than doing it by hand, but the results have a nice look to them.

Its certainly more challenging than normal. If you went at it from the 3D terrain and no restriction to keep the shape of the coastline matching the provided pattern then its a lot easier. Usually doing 3D is a lot more effort up front and then you get a lot for free down the line.

I would pay a large amount of money to watch RedRobes saddle a velociraptor.

As would I. Also, digging the effort and approach.

Thx - I would pay a lot to not have to ride one !

So this eves effort got limited success again and I got a bit frustrated with the rivers not being thin enough so I grit my teeth and hit the code base a bit more. I made it get the vegetation to suck up more water as a param and added another param to the ever growing huge list of knobs I can twiddle. I can now also set the vegetation rotting amount so it accumulates height where vegetation grows.

The idea here is that, where warm enough, usually next to rivers it has the conditions to grow veg well. When water flows, if its too much it kills the vegetation. So you have these wider flows of wet mud and the water spreads out. If the veg is allowed to grow next to it then it sucks up some of the water on the edge of the water flows and dries it out. If its thin enough water then the veg persists and now it drops height down there and builds up a bank then it forces the water to route around the veg and the water flow gets thinner. If all of the water is squeezed then it stays deep enough to keep the vegetation killed so it keeps the thin center of the water running.

Heres the latest run...

### Latest WIP ###
ThinnerRivers1.png ThinnerRivers3D_1.png

Theres a lot of nice things in the image but if I can highlight this area:

Regrowth.png

This is where the river used to be wider, then by turning down the rain and snowfall and letting it drain out a bit, the vegetation has regrown into that river bed forcing the river into a line again. Theres instances of this all over but most of them you need to know how bad the river was before it has regrown because in most cases it looks normal whereas it would have looked quite bad.

I had a few more ideas to add to it which might help but its a bigger coding effort. I wrote this app in 2007 so quite a while back when we had a lot less memory and you had to be a bit conservative with what data values per pixel you would store. But now with the 32 or 64 Gigs of RAM you can go quite bananas or have bigger terrain tiles to process at once.

What would be nice, and effective I think, is to have two types of height. One is rock, the other is soil. Soil is on top of rock and has wildly different erosion amounts. So once you have eroded through the soil you are on to bedrock and then it slows down a lot. So you can force the water into channels quite quickly without having these deep gorges slicing their way through the map - especially at the base of the mountains and big slopes which have accumulated a lot of water from large area and snow melt.

The rotting veg and sediment deposition can add to the soil height not the rock height so hopefully you get better river bed braiding without it cutting it into a deep channel. I don't think this app will ever do ox-bow lakes and that serpentine river flow because I don't erode sideways on this app. I think that would be quite hard to do but I have seen people write something where that does work.

Well I guess I have to decide what I am going to do with this map now !

[Diamond]

That is crazy that you can finesse this thing to take into account vegetation, river sediment, etc. Pretty amazing stuff.

By the way, I like where it's at right now.