Ore in 10.0?

The general locations of ores didn't change in Update 10 - only their distribution. Looking around the usual places should still provide you with the ore you seek - it's just no longer there in big chunks, but more distributed veins.

The distribution of ore into specific biomes and areas is intended - different locations on the planet are supposed to give you access to different resources, requiring a decision on where to settle and trade to gain the other resources. In singleplayer unrestricted claim papers are available with the correct settings, so multiple areas can be settled in.

Not sure what you mean with "old" ore spawn method? We never used this one before.

Originally posted by FluffyPotato: How hard is it to find in grasslands? I haven't played in a long time and the last time I played iron was everywhere. I kinda hate how deserts look and I wanna play with just a few friends. Building the infrastructure to transport iron without access to it first seems very annoying.

Also is there any way to change how ore spawn is done now? I would prefer to make it spawn under mountains if that's possible.

The locations where ore spawns hasn't changed, even the amounts are still nearly the exact same - it is a sole change of distribution to make it available more spread out over the biomes and less of singular massive chunks. You can adjust ore spawn via WorldGenerator.eco, but that is pretty complicated and undocumented.

Originally posted by Dani:

Originally posted by SLG-Dennis: Not sure what you mean with "old" ore spawn method? We never used this one before.

It used to be more scattered like it is now but that's a few years ago

It is not "scattered", given there is no clusters mechanic behind, but a vein one. Before it was a chunk-like generation. If you take a look at a hollowed out chunk with just ore, you can easily see the differences between "cluster", "chunk" and "vein" generation. I think there was a picture in some developer blog, I'll see if i can find it later to post here.

Originally posted by Dani: Join a server, take a pickaxe and give it a go.
Been on 3 different servers in the last week and have been mining for hours and hours ...
Mostly tiny "veins" here and there.
Maybe I have been unlucky and landed on servers where the algorithm wasn't doing that great.

There is developer commands that allow the clear the whole world or any amount of chunks from anything but ore, so we can easily adjust and test the distribution. Maybe the problem is the expectations of veins being always chunk sized, which they aren't. The requirement to use drills and have a lot of byproduct in mining is intended.