So, while I love the mod in all it's iterations, one thing that has irked me has been it's compatibility with Alien Biomes. While no crashes happen (Thank god) the generation of the underground levels isn't exactly how one would expect the underground to be. Basically, while the normal biomes that spawn will have the cavern entities and such, there are often large open spaces that require no mining out at all thanks to the generation being affected by Alien Biomes.

Would it be possible for you to add proper compatibility with Alien Biomes so that the caverns generate as intended and not with huge open areas?

I'm not really sure what would be causing that. I don't really know how Alien Biomes works. I might look into it if I have some time, but I doubt that will be any time soon. I'm very busy with university at the moment.

Could you maybe provide me with some more information on what these large open areas are and why they are generated? If it's easily fixable, I can make a quick update to this mod.

I think it's due to the terrain generation that Alien Biomes affects. It adds more ground tiles that can generate in a world to simulate more biome types like snow plains, volcanic regions, etc. I've provided a screenshot of how an underground area now looks when it first generates with Alien Biomes. In the screenshot if you look at the map you can see what looks like a normal world generating, though in this case it's showing a snowy biome that came from Alien Biomes with a small portion of actual cavern wall entities shown beneath my player character. I'm not sure what was done to make Surfaces replace the normal Factorio terrain tiles with the cavern stuff, but I think maybe through that same method with a mod dependency check it can be expanded to the tiles and biomes added through Alien Biomes.

[img]https://i.imgur.com/MpV8HzW.jpg[/img]
And if the img tag doesn't work, here's a direct link to the screen shot. https://i.imgur.com/MpV8HzW.jpg

It looks like some ground tiles aren't being replaced like you mentioned.

I took a quick look at the code again. There appears to be a list of tiles that may be replaced in the code (to prevent concrete and bricks from being replaced I suppose). It already includes support for Alien Biomes, but it might be outdated. It shouldn't be much work to fix this, I'll probably look into it soon.

Or, in case you want to fix the issue yourself, feel free to create a PR on Gitlab. The list of tiles can be found here: https://gitlab.com/Danacus/surfaces-redux/blob/master/script/const.lua

Thanks for reporting the issue.

I've added support support for Alien Biomes, it only took me a few minutes.

I didn't test it however, so please let me know if it's working, or if I broke everything.

It appears to be working now. I generated a new game and noticed that one of the new generations had the biome of the screenshot I provided above get replaced with the underground stuff.

That's good to hear! I've heard someone else saying it didn't work for them, but they were probably using an old save that didn't get migrated properly.