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Making Minecraft Spherical

(www.bowerbyte.com)
899 points iamwil | 14 comments | 28 Aug 25 18:12 UTC | HN request time: 0.861s | source | bottom
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reactordev ◴[01 Sep 25 15:28 UTC] No.45093496[source]▶
You should definitely have a look at space engineers. They have a similar spherical problem with their voxels and I don’t think they went half as far as you did when implementing “orbital bodies”.

As someone who is rather keen on space, gfx, and the algorithms that render them. Kudos. The problems were known to me, which is why I didn’t attempt it, however - the distortion correction, the chunking, I’m thinking if you just limit how far down you can dig (half way to the “core”) it will be fine. You won’t run into those tiny squished blocks that make up the core.

It’s also important to call out the quad-sphere. This is what makes it doable. Naive devs may just map lat long to sin cos spherical coordinates and call it a day, not realizing that their poles are jacked up. The cartography problem. I’m really glad to see that called out as people don’t realize WGS84 sucks for mapping a sphere.

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lsaferite ◴[01 Sep 25 15:32 UTC] No.45093544[source]▶
Not allowing excavation to the core solves weird gravity issue as well. Astroneer had super weird gravity at their planet core. You can get stuck oscillating there.
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1. reactordev ◴[01 Sep 25 15:35 UTC] No.45093570[source]▶
If you really wanted to go for realism, there would be NO GRAVITY at the core. :P

As you dig down you would get lighter and lighter on your feet.

Any mass you are below (within the sphere of Earth) will exert a gravitational pull in one direction, while the mass above you (also within the Earth) will exert an equal and opposite pull.

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2. ricardobeat ◴[01 Sep 25 15:45 UTC] No.45093671[source]▶
That's how it's implemented in the game!
3. lsaferite ◴[01 Sep 25 15:47 UTC] No.45093684[source]▶
Yeah, I'm mostly aware of that. Weird didn't mean 'wrong' in this case, just weird for a terrestrial-bound human. :)
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4. reactordev ◴[01 Sep 25 15:51 UTC] No.45093730[source]▶
There’s all sorts of weird physics in the universe ;)
5. nomdep ◴[02 Sep 25 00:24 UTC] No.45097858[source]▶
If you REALLY want to aim for realism, gravity should depend on all quads on the planet. So, if you were to build a huge floating island, the gravity between it and the planet would be less than the usual
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6. DrewADesign ◴[02 Sep 25 01:36 UTC] No.45098229[source]▶
If you really truly wanted to aim for realism, digging to the core would require a huge budget and an international coalition that would get bogged down in politics and mismanagement and it would never happen.
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7. reactordev ◴[02 Sep 25 06:01 UTC] No.45099596{3}[source]▶
30 year pension plan.
8. hdjrudni ◴[02 Sep 25 06:37 UTC] No.45099794[source]▶
If earth was just full of water.... as you swam deeper and deeper there would be more and more pressure upon you. Would there be a point where that pressure would start to lessen as the water is pulled in all directions?
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9. chii ◴[02 Sep 25 06:57 UTC] No.45099923[source]▶
> pressure would start to lessen as the water is pulled in all directions?

the pressure would never lessen, just increase slower.

The gravity at the center is zero, but the mass above you is not exerting just gravity force (which gets cancelled out by the opposite side), but also pressure (from the weight of it falling down).

This means the water pressure would steadily climb, but at a slower rate as you move nearer to the center, and will be at maximum at the very center.

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10. posix86 ◴[02 Sep 25 07:27 UTC] No.45100095[source]▶
Awesome question!
11. b3lvedere ◴[02 Sep 25 08:59 UTC] No.45100610[source]▶
Just a thought; I do wonder in reality if there is an actual single physical point that has any form of material but totally zero gravity. I think anything, as longs its size is above the planck length, has some gravity.
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12. Filligree ◴[02 Sep 25 13:08 UTC] No.45102634[source]▶
If nothing else, your own body will exert some gravity on you.
13. reactordev ◴[02 Sep 25 14:36 UTC] No.45103695{3}[source]▶
Correct. Gravity would be net zero but the pressure would be the entire worlds oceans.
14. noahbp ◴[02 Sep 25 22:40 UTC] No.45110039[source]▶
>As you dig down you would get lighter and lighter on your feet.

Fun fact: Gravity doesn't decrease the entire way down! Only when you get to the core does it decrease monotonically: https://physics.stackexchange.com/questions/18446/how-does-g...