Query the hardware and initialize the settings for the best user experience

[cosin15]

Problem

It is amazing how much the user experience improves when increasing the value of num_emerge_threads.
The sad thing is that I didn't know about this setting until recently.

Solutions

Query the hardware and initialize the settings for the best user-experience.

Alternatives

Don't hide num_emerge_threads

Additional context

No response

[kromka-chleba]

The feature unfortunately causes some mapgen bugs: #9357

[appgurueu]

The feature unfortunately causes some mapgen bugs: #9357

(Side note: I'm not sure how much of a problem this is with the special case of pure Lua mapgen which does not rely on overgeneration.)

[rubenwardy]

See #13674

[cosin15]

The feature unfortunately causes some mapgen bugs: #9357

(Side note: I'm not sure how much of a problem this is with the special case of pure Lua mapgen which does not rely on overgeneration.)

What is this 'overgeneration' good for?

[SmallJoker]

Related #5024

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What is this 'overgeneration' good for?

It increases the chunk size that the mapgen is working with (default is 5³ mapblocks = (5*16)³ nodes) with an 1 mapblock wide border so that you can randomly place oversized/overlapping structures (such as trees) into it without instantly risking a cut-off.

[jeremyshannon]

(Side note: I'm not sure how much of a problem this is with the special case of pure Lua mapgen which does not rely on overgeneration.)

Most mapgens use overgeneration, if this is supposed to be helpful for newbies who just loaded Luanti for the first time, inserting glitches into their brand-new Voxelibre map is gonna give a bad impression and defeat the whole point of the automatic setting initialization.

[cosin15]

Related #5024

What is this 'overgeneration' good for?

It increases the chunk size that the mapgen is working with (default is 5³ mapblocks = (5*16)³ nodes) with an 1 mapblock wide border so that you can randomly place oversized/overlapping structures (such as trees) into it without instantly risking a cut-off.

Does that imply that when mapgen runs, the chunk (5^3 blocks) might already have trees in it at the bottom?

This looks suspicious to me:
https://github.com/minetest/minetest/blob/5bcb7983ec1648b9993e4092be014308726af383/src/servermap.cpp#L206

The neighboring chunks need to be locked as well I guess since it is not just one chunk that is written to.

I also don't get, why this function should be multi threaded?

[lhofhansl]

Couple of observations from my setup (with sqlite):

• More emerge threads only help with generation. Loading already generated blocks actually slows down!
• More emerge threads increase server lag, especially with expensive generation logic.
• There are some bug, like cut-off trees.

Maybe things are different with different DB backends.