Minecraft Forums

I seem to have a memory use spiral when I try to load my world that causes a crash in just a few minutes. I have successively increased the memory available to minecraft, each time taking a few more seconds to fill up according to the F3 display. I also looked up a way to increase garbage collection but that doesn't seem to be the issue. Right now I am using the following java commands in my profile- -Xmx3G -Xms3G -Xincgc.

I'm not using mods of any kind except amidst (that's not a mod, right?), but I am working on a large project in the middle of a huge jungle. I set my render distance to only 4 chunks because I was having some framerate and strange behavior, I don't need to see much to work on the project. That helped for a long time, but now it is out of control. I suspect this might be due to a bug.

What should I do? I've tried moving away from the area I'm loading in but I don't have much time before it crashes.

Going to bed early so the monsters don't come. I already knew about that one though.

I just spent several days exploring a world that has half the biomes in the game within 3000 tiles of the start. I don't want to do that again. I don't want something that explores for me, but I want to know the world has all biomes within a certain range of 0,0. There are probably world seeds with all biomes but I would prefer to gen my own and then reject it if it doesn't meet my criteria.

Any suggestions? I don't want to waste any more time with bland worlds.

Yeah, I've been getting that too. Holding and using multiple maps in your inventory messes up the pointers. It's hard to research because of all the historical map bugs. I guess maps have always been very buggy.

This bug seems to go away if you log out and then log in and stick to one map at a time.

EDIT: As far as I have seen, the map still explores properly even though the pointer is invisible, so it might still be worth having all the maps you need even though its hard to tell where you are sometimes.

I rather enjoy exploring as long as I'm seeing some new stuff along the way. When I'm seeing nothing but repeating patterns I get discouraged. I'm almost done mapping a grid of 9 fully zoomed out maps over quite a few hours, and I'm not seeing many biomes. I'm not sure they even exist in this particular world, and I don't think I want to spend another eight hours just to find that out.

I'm not happy with a 50:1 ratio between occurrences of one biome to another. 10 or 15 to one would be a lot better I think for rare biomes.

Yeah, I came here to complain about the rarity of some of these biomes. I think I have an idea of what the problem is. I would guess that the temperature, moisture info is generated with some variation of Perlin noise.

A Perlin noise function usually gives nice looking random brownian motion values between -1 and 1 or 0 and 1. Because the values returned within a range, for instance 0 to 1.0, you might intuitively think that, for example, values above 0.9 would occur 10% of the time. Perlin noise however is generated by combining samples of a noise field at differing geometric scales, which will tend to strongly favor values in the mid-range, while suppressing extreme values. It is similar to using multiple dice rather than a single die.

For example, if you have a single 6 sided dice and roll it many times, you would expect to get values 1 thru 6 with a fairly even distribution. However, if you add another die, for a possible result from 2 to 12, the results will not be evenly distributed. To return an extreme result of 12, you must roll two 6's. To get a mid-range result of 6 you can roll 5 1, 1 5, 2 4, 4 2, and 3 3. So you are actually five times as likely to roll a 6 than you are a 12 or a 2.

Perlin noise works similarly. Generally you will have a noise field sampled at several octaves that are combined for a final result, so to get an extreme result, all of the samples at each octave need to be extreme! As you can imagine, that greatly increases the rarity of extreme values.

The reason why it's not that hard to find map seeds with the extreme values and thus desert and jungle, is because with standard Perlin noise, there are artifacts near the geographic origin (usually where the player spawns) that will make extreme values more likely.

For a 1D example, lets say we have a set of numbers, sampled at 3 octaves multiplied by 2.

123456789 Oct1
112233445 Oct2
111122223 Oct3
Averaged Result (rounded):
112234456

You can see that at the origin, the extreme low 1 is represented in all three octaves and comes through to the final result. As you move away from the origin, things become more muddy and middle ground, even when some contributors are extreme highs.

In conclusion, I think that the devs did not actually examine the distribution pattern of their noise algorithm, but rather made false assumptions about it, therefore people are getting vastly more temperate biomes than extreme biomes. I love some of the new biomes, but the impact is greatly diminished when you want to find a desert and you come across your 15th flower forest or roofed forest. As cool as those biomes are to look at, if you are looking for something else they become repetitive to the point that you get angry at seeing another one. In my world after much exploring, I'm actually seeing fewer biomes than I saw in previous versions. Not one example of ice, mesa, desert or jungle within 3000 squares, and their might not be any anywhere if my theory is correct.

I had the same problem, and when I turned OFF Advanced OpenGL the problem went away and I didn't notice any downside.