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jacobsjo.eu
jacobsjo
@jacobsjo.eu
100 followers 95 following 25 posts
Computer Scientist, Minecraft datapack toolsmith, Photographer

jacobsjo.eu
https://github.com/jacobsjo/
modrinth.com/user/jacobsjo
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jacobsjo.eu
jacobsjo @jacobsjo.eu · Nov 17
Have you ever wanted to see a map of how a specific #minecraft seed generates? But you are playing with datapacks that modify worldgen? I've got an online solution for you:

map.jacobsjo.eu

(Works with some mods too, but not with all)

#mcdev #DatapackShowcase
A map showing Minecraft biomes by color. The map shows multiple continents surrounded by water. The water-color also differs based on the specific ocean biome. Shading indicates terrain relief. On one continent a symbol indicates the spawn point.
jacobsjo.eu
About a year ago, I held a panel at @smithed.net Summit about my Minecraft biome-layout editor Snowcapped, including a step-by-step guide on how to use it. I've finally uploaded an edited version of that panel. #mcdev

www.youtube.com/watch?v=9S0L...
Intro to Snowcapped | Smithed Summit Panel
YouTube video by jacobsjo
www.youtube.com
November 27, 2025 at 3:08 PM
jacobsjo.eu
I've just released version 1.4.0 of my worldgen-devtools mod that features a /environmentattribute command that lets you query and set overrides for the new environment attributes introduced in Minecraft 1.21.11. Get it here: modrinth.com/mod/worldgen... #mcdev
A screenshot from a Minecraft desert but with a red sky. The chat is open and shows 2 lines: minecraft:visual/sky_color: "#6eb1ff" Environment attribute minecraft:visual/sky_color set In the chat input box the following is being written: /environmentattribute set minecraft:visual/cloud_color "#00FF00"
November 25, 2025 at 8:32 PM
Reposted by jacobsjo
noyb.eu
🗞️ "In this moment of crisis, #Europe should not cripple its best weapon against #US tech dominance, but enforce its laws, defend its sovereignty, create the space for innovation, and prove that democracy can tame Silicon Valley."

Read more 👉 www.theguardian.com/commentisfre...
The EU has let US tech giants run riot. Diluting our data law will only entrench their power | Johnny Ryan and Georg Riekeles
The GDPR is Europe’s defence against digital oligarchy and child harm. Deregulation plans are misguided, say Johnny Ryan and Georg Riekeles
www.theguardian.com
November 14, 2025 at 11:00 AM
Reposted by jacobsjo
metr.org
We ran a randomized controlled trial to see how much AI coding tools speed up experienced open-source developers.

The results surprised us: Developers thought they were 20% faster with AI tools, but they were actually 19% slower when they had access to AI than when they didn't.
July 10, 2025 at 7:47 PM
jacobsjo.eu
Today is the 5th anniversary of #Minecraft data pack #worldgen! Snapshot 20w28a added the ability to define custom biomes, structures, etc. through data packs. It's hard to overstate the impact this change had on modded worldgen. Very proud of what our community has made with it so far! #mcdev
A screenshot of a Minecraft world that looks like a cake. It consists of 4 layers. Each layer has frosting on the top and brown cake below. There are a lot of candles on the cake. In the foreground, there is a pink "river". The sky is pink with the normal white Minecraft clouds.
July 8, 2025 at 10:38 AM
jacobsjo.eu
I've tried to fix that one multiple times over the years. Finally had the right idea of how to do it. It was surprisingly simple.
misode.dev Misode @misode.dev · Jul 6
The wonderful @jacobsjo.eu has just fixed a longstanding texture bleeding issue in NBT Viewer (and other tools using deepslate) 🎉

Compare these before/after images for yourself:
Bastion bridge structure before the fix. Notice the edges of blocks. Bastion bridge structure after the fix.
July 7, 2025 at 1:50 AM
Reposted by jacobsjo
dinnerbone.com
I almost fell for a scam site today, pretending to be the homepage of an OSS project that I was looking for.
It looked convincing until I scrolled to read more text. LLM slop is getting scary good at "looks good at a glance".
I don't even know _how_ they managed this. Feeding LLM into LLM somehow?
A screenshot of a section of a website, where the text is describing what the text itself should say. For example, 'Clear Message: Show a short line like “DxWnd is safe, open-source, and malware-free.”' instead of the actual example text.
June 30, 2025 at 9:59 PM
Reposted by jacobsjo
worldgen.dev
I'm disgusted by the concept of generative AI tooling for Minecraft mods. This isn't the first one and it sure as hell won't be the last, but it made my blood boil regardless. (1/5)

#mcdev #minecraft
A screenshot of a website. The title is "Create Minecraft Mods with AI".
May 26, 2025 at 6:43 PM
Reposted by jacobsjo
misode.dev
The dialog generator now has a visual preview, closely matching vanilla! #mcdev #datapacks

misode.github.io/dialog/?vers...
May 17, 2025 at 4:31 PM
jacobsjo.eu
The update also adds dry grass to the nether wastes, fallen crimson trees, and rare soul lanterns to ghost trees. It also fixes a bug with pillars cutting off caves.

The update is out now. You can get it from
- Modrinth: modrinth.com/datapack/lav...
- Smithed: smithed.net/packs/lavaflow
April 19, 2025 at 6:50 PM
jacobsjo.eu
Turns out the firefly particles make very good nether ambient particles too. In the Lavaflow 1.21.5 update, I've added them to the ghost forest.

#mcdev #minecraft
April 19, 2025 at 6:50 PM
jacobsjo.eu
Sort of. Not all mods work (only those that do their worldgen like a datapack work), but when only using those it is possible to add multiple at the same time. You'll have to add each one manually though.
April 11, 2025 at 11:40 PM
Reposted by jacobsjo
xkcd.com
Tariffs xkcd.com/3073
April 8, 2025 at 12:03 AM
jacobsjo.eu
There is literally an image showing Tinkers' Construct and numerous other mods mentioned in the same section 🤷‍♂️
Screenshot of section "Mod content" on https://en.wikipedia.org/wiki/Minecraft_modding until the start of the subsection "WorldEdit"
February 16, 2025 at 1:31 AM
jacobsjo.eu
You can find the Worldgen Devtools mod on
- modrinth: modrinth.com/mod/worldgen...
- GitHub: github.com/jacobsjo/wor...
December 23, 2024 at 2:19 AM
jacobsjo.eu
Trying to figure out ancient debris distribution in Lavaflow, I wished to have a visual marker for each placement position. So today I've implemented a debug renderer for feature locations into my Worldgen Devtools mod.

Just released that in version 1.3.0 for mc 1.21.3 and .4.
Open with F3+F
#mcdev
A Minecraft screenshot from inside a old growth pine taiga, with a river in the background. A number of markers of different colors are placed on screen, consisting of a cube and text above. The closest markers reads "minecraft:patch_brown_mushroom", "minecraft:patch_taiga_grass" (2 markers), and "minecraft:forest_rock".
December 23, 2024 at 2:19 AM
jacobsjo.eu
Probably. I've also made Striders immune to fall damage so you can safely ride them down the lavafalls.

I've also though about adding some kind of "strider staples" structure to make it easier to get a strider to ride over the ocean.
December 18, 2024 at 1:41 PM
jacobsjo.eu
Also available on
- Smithed: smithed.net/packs/lavaflow
- CurseForge: www.curseforge.com/minecraft/mc...
- GitHub: github.com/jacobsjo/lav...
December 16, 2024 at 2:16 PM
jacobsjo.eu
Finally published a first Alpha of "Lavaflow", a #Minecraft worldgen #datapack / mod that completely overhauls the Nether. It includes lava rivers on 2 heights with lavafalls between them, proper valleys, oceans and more.

Check it out on modrinth: modrinth.com/datapack/lav...

#mcdev
Looking down at a nether fortress over a large lava ocean. In the foreground the end of a lava river is seen between crimson forest. The river leads towards what appears to be a lavafall, though that is only visible from the back. A lava river flowing through a soul sand valley. The valley is more flat the the typical nether. A large ruined portal is placed on the right shore. Behind the portal is a mysterious forest formed by trees with bone stems, white leaves, and glowstone. A elevated view of a lava river flowing though a valley with basalt deltas and soul sand valley biomes. Above the valley is a series of floating terrain stips that can be used as walkways. A tower in the foreground provides a connection between the valley floor and these walkways. In the background a bridge of a fortress can be seen reaching over the river.
December 16, 2024 at 2:16 PM
jacobsjo.eu
I've also updated my datapack map to reflect this change if 1.21.4 is selected. In the process I also added the y position of the structure start to the markers.
December 3, 2024 at 4:46 PM
jacobsjo.eu
For custom sky islands dimensions the only way around this issue until now was to change the biome layout to have a different biome at y=0. This is not possible to do with the vanilla end though.
December 3, 2024 at 4:46 PM
jacobsjo.eu
A change I would like to highlight from #Minecraft 1.21.4 is a bug-fix: MC-272062 - "Dimension padding doesn't affect the start piece." This fix makes it possible for data packs to add structures to the end without them ending up in in the void at y=0. #mcdev
December 3, 2024 at 4:46 PM
Reposted by jacobsjo
852dude.bsky.social
Did you know about the Pronouns labeler?

Subscribe to this, pick your pronouns, and see the pronouns for all other users on the site.

bsky.app/profile/pron...
bsky.app
November 22, 2024 at 3:43 PM
Reposted by jacobsjo
misode.dev
I'm really glad I'm just developing a website for making zip files for a block game. Takes away a lot of pressure when rolling out major rewrites!
Switch to mcdoc #614 misode merged 122 commits into master from mcdoc 23 minutes ago
November 27, 2024 at 4:21 PM
jacobsjo.eu
Well its worth exploring (once there are actually packs worth including), but downloading files (that are potentially large; resource-packs for localization) directly from an API initiated by just opening my map with URL parameters just sounds like a bad idea. Caching would also be a problem.
November 25, 2024 at 5:20 PM