November/December 2024 Challenge: The archipelago of endless wrecks

[Redrobes]

I don't usually have time to enter a challenge and this one might still be another that I start and end up throwing on the dump of unfinished attempts but often as the yuletide season approaches it can go quiet and I can work on something. These shapes to make a map challenges are usually popular and no doubt I will be among stiff competition but its a bit of fun to try anyway.

A long time ago I did a lot of islands for the Ansium co-op world and I still have the shaders from that to use. So if it is possible that I can massage the starting image into something 3D then I can have a go at using them to colour it for me.

Looking at it then I think that the black looks like land and white is sea. Theres a lot of black at the top so that might prove interesting to get that mountainous but somehow it will have to be. I like the right side better so I will do a square map.

My normal method to make something 3D is to use my zebra method but this map has a lot of detail and the zebra method involves using a pen to create contours. This time I think I will try to layer up copies of the map which have been blurred and then merged together with layers so that we blend up from the coast to the top of the map. I usually work with white as the high ground so first thing is to invert the map and then add all of these layers.

I need some height information below the sea level too some I have to do the same process to create some fake bathymetry. Once all done then I have a greyscale image with 8 bit per pixel shades going from 0 to 255 brightness which at some undefined point in the greyscale needs to look a lot like the original image. That grey value needs to get mapped to sea level and then I must convert the shades higher than that into heights above sea level and those shades darker to depths under the sea level.

After I have them mapped into "float" heights as a digital elevation model then I will need to find some height mapped mountains and blend them into the very high ground.

So after an hour or so here are some starting WIPs.

NovDec_02.png NovDec_03.png NovDec_04.png

NovDec_05.png
### Latest WIP ###

[Chashio]

Nice looking start what 3d software are you using?

[Redrobes]

Thanks - the greyscale height generation stuff so far has just been using a paint package with layers. I did successive blurs, used the curve tool to get the brightness adjusted each time and then layered them all up and merged them all back together.

Then I have a greyscale image which has a bit of height and depth but its not very controlled. But its a start. At least with something I can expand it or pull it up and rescale it etc. I will add some height mountains and hills etc and it will look a lot better, more realistic, less blobby.

To add this mountainous height maps to the blobby landscape thing will require my 3D utilities. All they do is take in some DEM inputs and multiply them or add them and then spit out the array of floats in DEM format again.

You can do that in a paint package too but its all in 8 bit which causes all of those steps which is the 1/256 greyscale height resolution. So although its more visible and easier to see what you are doing, its easier in DEM floats to do it then you dont have to worry about the limitations all of the time.

This 3D view above was done in another of my apps and this one is the debugging tool to show the height maps and I can see what it looks like. This app is a windows exe (or WINE in linux) and I gave it away a while ago so if you want this one just PM me and ill email it over. It can take in a bitmap for the height (or a float DEM) and a colour bitmap too and it shows it then you can spin around it and have a look.

[Chashio]

Oh, interesting. I use Blender for most of my 3d stuff, though I haven't tried loading a height map in it yet, I have used it to sculpt and model a few maps from scratch.

[Diamond]

Very cool start, RR! I'm looking forward to lots of shipwrecks.

[Redrobes]

Oh, interesting. I use Blender for most of my 3d stuff, though I haven't tried loading a height map in it yet, I have used it to sculpt and model a few maps from scratch.

I should have another go at Blender. I tried a few times a long while ago and the UI was very weird. It was weird enough that the developers even said it was weird and so they had an overhaul and made it a lot different and everybody says that its better since.

Very cool start, RR! I'm looking forward to lots of shipwrecks.

I havent decided on the scale yet but from looking at the original splats, as islands there seems to be a lot which implies a shallow sea and lots of undersea action. I could do the map realistic or I could make it into a chart with plots of wrecks. Havent quite decided yet.

[Chashio]

Yeah, Blender goes through changes. I started with version 2.8, so I dunno what the UI was like before that but a couple days ago I learned something new in version 4.0 and then installed the latest version yesterday which has a lot of updates and that thing I learned doesn't work anymore, lol. It can be a little frustrating that way having to learn new stuff but I like it in general. But the latest version has the ability to use their project gold artistic brushstroke styling which I'm looking forward to exploring.

[Redrobes]

A new version of Blender has been released in the time since the last post. Looks like it has some new nifty features and more upgrades to the UI. I really must try that again.

So in the last post I had some blobby landscape in greyscale format and it needs some mountains. I dragged out a mountain tile I got from the Shuttle Lidar data - do a search for "SRTM 30m download" - and you can grab bits of the earth. This one is from somewhere around Pakistan or similar in the Himalayas. I have flattened it to remove the low frequency height leaving just the mountain detail. The greyscale of that is provided here in case anybody wants to use it.

GreyscaleMountains2048.png Mountains3D.png

Taking the blobby height greyscale I just used a paint package curve tool to select where I want the mountains placed. Then I can use my 3D tools to multiply the mountain by the greyscale selection. After that I can add those masked mountains back onto the original blobby height map to give something similar but with extra sharp mountains in the selected areas.

MountainMask1.png MountainMask2.png

After having done that I created a general noise greyscale and added a bit of that into the mix too all over. Its all been offset and scaled so that 0 is sea level and the mountains are about 2000m high and the noise is something like 50m high.

LandAndSea1.png

As part of that image I also took the original black and white map of the area and where it was sea, dropped the height by 50m. In that way it makes the coastline match up that little bit better with the original.

After that, just as a test, I clamped the height map so that there is no negative values and used some basic texturing based on the height to make a colour map image to paste on the top of the height. I'll show that in a new post so that the WIP grabber doesn't get the wrong one like it did last time...

The landscape is still a bit blobby for my liking but it will have to do. I will run some erosion passes on it and see if I can generate some rivers and get a little detail into those cliffs. As a side effect of running erosion it will spit out the water height map which includes rivers, and also makes a stab at guessing the vegetation and temperature of it all so we can then add more textures based on those values too.

[Redrobes]

### Latest WIP ###

LandNoErosionNoVeg1.png

Just bare earth, sand, sea and rock at this point.

[Redrobes]

I set up the erosion run and twiddled the knobs on it for ages trying to get a good result. This is not bad but my erosion app is such a pig to operate.

### Latest WIP ###
ArchMapTopRender1.jpg

The land is still full of water and I might run it again and let it continue to drain out the landscape and get thinner rivers. I know, I know - I need to do the basin fill operation first... but it doesn't have it and the way its designed to run is that you keep adding water till everything overflows then you let it drain out but it takes forever.

ArchMap3DRender1.jpg

This is how this one looks in 3D.

MoreBathymetry1.jpg

The other bigger issue is that there is not enough bathymetry to show up the sand bars etc which I wanted for all of the ships to get grounded on and cause all of the wrecks. The above image shows a little bit of one showing through but its not frequent enough.

To fix this I need to raise up the sea bed in places. I could do that with a greyscale painting but I think I will try to see what happens if I just raise all of the sea bed up a bit and maybe add some noise to it. I don't want it raised higher than sea level but it needs to have less depth under the water from its current setting. Id like to see some sand bars and other features as currently the sea is completely featureless.

Since I will have to run it all again, ill try to get better rivers at the same time.