SPAAAAAAAAAAAAAAAACE

Rather than being a development log, this topic is for discussion as to how the space aspects of the game will work. These discussions should focus mostly on the "how" and "why", technical stuff for the most part, though space related gameplay is another important aspect.

This is an open topic and everyone is free to contribute ideas, speculation, and opinions.

To start, the topic is planets
--------------------------------------------

================
Shaping Middle Earth
================

The first and most obvious question to ask about planets is what kind of shape does a planet made of cubes have? There are, of course, two obvious possibilities, each with its own pros and cons. These are, of course, the CUBE:

And the SPHERE:

Wow, those are bigger than I thought. I might resize them later.

So, which is better? I don't have strong feelings one way or another, but there are different challenges facing each of them.

First, let's discuss the CUBE. Obviously more Minecrafty, the world would be simple to map. 6 faces to stand on and 12 edges to cross, plus the additional airspace at the edges and corners. When you walk off the edge you simply rotate 90 degrees and are standing on the next surface. Time of day would be unique for every face, as would the sun's path through the sky. Sounds simple enough at first glance, but it's really a bit more complicated than that. Think about what happens when you are standing on the edge of a world. First of all, which face is considered "up"? If there was grass that is an important thing to know. To get around this, for chunks shared by two faces, you need to figure out which chunk will host the rendering, and which faces it will draw as up. This becomes more confusing with the addition of things like furnaces and torches which need to be treated differently. Then there is the matter of which surface you walk on when the border is not a convex square. What if there is a channel cut out so you are facing a vertical wall. Do you walk up the wall? Which way would you fall if you jumped off a block in the airspace at an edge? The more you try to do the more complicated it becomes, and while it would be cool, I'm not sure what rules you could set up to make it work.


So then there is the SPHERE. It has the advantage of working just like regular minecraft for most of the time. You keep on walking along the equator and you end up back where you started. Gravity is always straight down regardless of where you are standing. Time of day depends on your longitude. Equatorial wrapping of the terrain can be accomplished via averaging the terrain noise at the seam, much like how you switch from one biome to the next in 1.8. Sounds good so far, but now that you have a sphere, what do you do about the poles? It's a well known fact that it is impossible to project a flat surface to a sphere without distortion, and with Minecraft being made up of cubes, there is zero room for distortion, meaning the world can't truly be spherical.

So what if it's not spherical? What if it were a cylinder? From the ground, you're not going to notice, most of the time, and from space, the blocks are too small to pick out the deformation of projecting a cylinder to a sphere. Of course then there is the matter of what to do about the border between the lateral surface and the disks at the ends. The disks would be the poles, and would go a long way towards reducing the distortion that would normally occur up there, but the border won't line up properly, and any seam will be noticeable. Even worse, it won't be the correct scale, since on a cylinder the circumference at the edge is the same as at the equator. The only way around this is to disconnect the two. Put some border between one and the other which obscures the transition. My vote: perpetual polar storm.

Chalk it up to the unnaturally strong Coriolis effect caused by 20 minute days if you'd like, but there is a massive wall of wind and snow near the poles. As you get closer, visibility drops sharply and you discover building or digging is impossible. As you press onward you become completely disoriented. Then, just as soon as it came, the winds passed, and you find yourself in a new land covered in a solid layer of ice and snow. In the distance you see santa's workshop or some tap dancing penguins or something, I don't know. Dr. Mackeroth writes the stories, not me. Anyway, it would be a nether-style portal linking one surface to the other. Of course, it wouldn't have to be snow and wind. If we were dealing with single-biome planets it could just as easily be a sand storm, or even just really thick fog. As long as one side isn't visible from the other, it could be anything.

So that's how I would do spheres. If anyone has any good ideas for how cubes might be implemented at the edges, I'd love to hear it.
Incidentally, having a sci-fi kind of planet like a ring-world or a massive Gundam style space colony would actually be the simplest to implement.

*Pictured above: simple

===============
Size
===============

Now that we've addressed what shapes are possible for a planet. What would make a good size for the planet?

This is what the current terrain generator produces. I think it might be around 20-40 km across. If we were to use the original terrain generator, I would say that's a pretty decent size for a planet to be. Larger than this, and it will just start to look like TV static, because of the finite levels of fractal noise being used to produce the desired terrain. If it used more tiers, you could make it larger. Alternatively, we might consider using a customizable terrain generator like www .minecraftforum.net/topic/100820-togoss-programmable-minecraft-map-generator/ to make all sorts of different kinds of planets of various sizes. We could even have a world of floating islands in which the surface of the world (if there even is one) is obscured by a thicker layer of atmosphere.

The other thing to consider is the gameplay factor. In a game with space travel there needs to be a reason to travel from planet to planet aside from the novelty factor. One reason might be that the valuable resources differ from planet to planet. You also have to make sure that planets are small enough that you can fully explore them and get from place to place without it being completely impractical. It's all a balancing act, and will likely come down to a lot of trial and error.


That's all for now. Next time will be about how to visualize planets from orbit and high altitude.

With the spherical model, I think we would have a problem with orientation of space crafts. Also, how large would the area between the ground and the "space barrier" be? If a ship is flying directly towards a planet, then it is warped close to it, would it have enough room to flip over and maneuver. If we want the planets' surface to be rendered in space thousands of blocks away, our render disdaces would need to me huge. I was thinking that we would just keep a stock image of a planet that you would see from space, so that it doesn't cause a problem with rendering, and when you got close enough to it, it would warp you into the planet's sub-space where the surface would render. I don't know what is possible, so maybe this isn't necessarily and everything would work out perfectly.

The goal is to be able to fly around at any altitude between high orbit and kissing the dirt. A big part of that is finding more efficient ways to draw terrain at a distance, which I'll go into into more detail with in my next article thingy.

Long story short, lowest level will be standard minecraft rendering with a few optimizations, highest level will be a cartograph painted on a sphere. The stuff in between where elevation starts to play a prevalent role is the interesting part and requires more in-depth discussion, though truthfully, I'm not sure yet how well it's all going to work. This is normally the kind of thing you build a game engine around, not just tacked on, and certainly not in Java. But I think it will work.

The difficulty with any whole world render is that you would have to explore the entire world for it to make sense. (By this, I mean if you have unexplored region of a planet, they will show up black on the whole-world render).
I personally believe that a spherical planet would be easier, but we have the difficulty of what would happen when we approach the planet's core. On the outside, it's easy, you can just rotate each 16x16 chunk by half a degree or so, which over 16 blocks, will have a hardly noticeable effect. However, after a few hundred meters to a few kilometres (depending on how large planets are), the rotation of blocks will mean that intersect each other completely. The solution to this is to shrink each block slightly; by turning into a pyramid with its top cut off (I can't be bothered to figure out what its proper name is). Then again, you will notice deep underground that blocks are smaller, but at least there will be the same amount.

Ignore those ramblings, I have the solution:

You make planets flat, but only from the ground. From space, you can project the terrain over a cube, or, with more difficulty, a sphere.

Dr. Mackeroth wrote:

(Toolongtoqoute)

Ehh... In my opinion what you see should literally be what you get, so I voted for cube shaped planets. With cube shaped planets you would avoid that problem, which is probably harder to work out then the edge thing, and cubes are more Minecraft-y.

Unless... maybe you could do some kind of combination of the shader mod(which can make flat worlds appear round) and some 4d trickery stuff to make a round planet have the same internal diameter as the external diameter. Wait that wouldn't allow you to make a hole through the world... Yeah... Ok, cube worlds would probably be best:
1: They fit Minecraft's style, as literally EVERYTHING is square or visibly made of squares.
2: They avoid many of the problems circular worlds impose.
3: Cooler, I mean they really are, at least im my opinion.

As for the 'what is up' problem, Maybe there could be transition blocks for the edges, if their done well there wouldn't be any huge problem(AFAIK) with cube worlds.

At least you should have a bedrock core. I can't imagine what would happen to your client if you are suspended in the center of gravity with orientation flipping hundreds of times a second.

IDEA! I just remembered, Minecraft is basically in another universe, and therefor has different laws. What says gravity on a cubeplanet has to be circular(ish)? What if between the faces, there IS NO gravity? Player physics would need reworking, but it could work. Physics for mobs and players could be sorta like Shattered Horizion without the manuvoring thingy- Ohwait, that wouldn't work ether... Ok, how about having it so theres a invisible, flat, triangular barrier starting from the center of the planet. If a entities center of mass crosses it they switch to the appropriate gravity direction.

I just found out Another huge problem with square planets: Underground. Any point under the surface would have TWO planes of gravity intersecting it, based on your position. Meaning that mining would be virtually impossible without random gravity switches. In that case, I vote for CIRCULAR planets!

And awesome Portal 2 Reference. Maybe I should do a four part plan for something?

Fenway wrote:

I just found out Another huge problem with square planets: Underground. Any point under the surface would have TWO planes of gravity intersecting it, based on your position. Meaning that mining would be virtually impossible without random gravity switches. In that case, I vote for CIRCULAR planets!

And awesome Portal 2 Reference. Maybe I should do a four part plan for something?

My previouss idea doesn't have that problem, the gravity zones would basically be 6 pyramids joined together, so theres no overlapping and any problems with gravity at the center can be solved by removing gravity down there.

or you could block the area that has problems with a thick layer of lava

How about this....if this is in the future what says there is no gravity...except for devices that make gravity....meaning all planets would have a 0g atmosphere.....and the only way to get gravity is to make a device.....but that runs into the problem of how does sand/gravel fall and how do you keep mobs and the players from floating off....

killerofpie wrote:

How about this....if this is in the future what says there is no gravity...except for devices that make gravity....meaning all planets would have a 0g atmosphere.....and the only way to get gravity is to make a device.....but that runs into the problem of how does sand/gravel fall and how do you keep mobs and the players from floating off....

So basically you've answered your own question as to why we wouldn't do a 0g planetary system.

I agree. Giving planets gravity is a good idea. I'll definitely do that.

You know, this thread was always my favorite. I have no idea why...

In other news, typing while riding on an exercise bike is really difficult. Using the mouse is fine, but the keyboard is difficult.

Dr. Mackeroth wrote:

You know, this thread was always my favorite. I have no idea why...

Definitely the visual aids. I should use them more often.

I agree, the visual aids are always a plus. For example, check out exhibit A.

EXHIBIT A:

Spoiler:

And that is why I'm doing textures and you're not.

*Fixed

Spoiler:

fr0stbyte124 wrote:

*Fixed

Spoiler:

omfg, I just spit out my teeth.

ectrimble20 wrote:

killerofpie wrote:

How about this....if this is in the future what says there is no gravity...except for devices that make gravity....meaning all planets would have a 0g atmosphere.....and the only way to get gravity is to make a device.....but that runs into the problem of how does sand/gravel fall and how do you keep mobs and the players from floating off....

So basically you've answered your own question as to why we wouldn't do a 0g planetary system.

Yes...your welcome.....

ectrimble20 wrote:

fr0stbyte124 wrote:

*Fixed

Spoiler:

omfg, I just spit out my teeth.

Gee, I wonder why?

what if you made somthing in the middle, like this:


**fixed image**

Except made of bedrock so I don't dig through to China. Wait, if I dig straight down and find someone living directly on the other side of the world, would that be my property? And furthermore, are airplanes going over my hose trespassing? Brainstorm.

One problem you need to consider is how to make it a complete circle. Most worlds are relatively unexplored. If somebody has only explored part of a world, then you can't plot the world on a sphere or cube. I think you need to pre-generate the world and not allow more to be generated. Then have some loop code, so that 1,000,000(or something) x + 1 = -1,000,000 x and you see the world that way.

Also, I think that the transition should not be seemless. Look at spore, for example. It has a galactic map, solar system map, and a planetary map. All of them are different. We should treat planets as different worlds to their solar system. That way, gravity is simpler on planets, as planets are still flat, so no changes there, and space is better.

Summary: Planets pre-generate to a set size, and can't generate more chunks.
Walking loops you to the other side of the world, you eventually walk back to where you start.
Solar systems different worlds like nether
Worlds sphere from space, flat from ground.

You should give a choice. 20KM for a small planet 30 for medium 40 for a large.