First, I REALLY appreciate the reply.
Nore wrote:Well, these metals are *on average* common. However, you need to find "veins" of them, which will be areas where you can find high concentrations of them. Thus, the gameplay objective is to make you find those veins, and establish an zinc mine somewhere, a chromium mine elsewhere, etc. This was however not done for ores that were not introduced by technic, and thus, the other ores are uniformly distributed.
I completely get that, and I realize that's the strategy to adopt now. Though I only figured that out after spending a lot of time reading through a large portion of this thread. I'm mostly saying that it's really important to make some reference to that in the manual, since there's a huge difference between expectations for these different metals, and that will affect gameplay and strategy.
I'm still trying hard to believe what you say about chromium and zinc being "common" on average -- which would mean I've encountered a statistical fluke in my world.
Can you explain briefly what the noise_threshold basically means in terms of frequency? For example, if I understand the oregen file correctly, zinc has a 1 in 6^3 chance of spawning a cluster below -32 without the noise factor. But the noise threshold is 0.5 -- is the noise a normal distribution? Does 0.5 mean there's basically a 50% chance *on average* of the noise exceeding that threshold to allow that 1 in 6^3 chance of spawning to happen? Am I interpreting that correctly? For chromium, the threshold is 0.55 -- how does that alter the stats? (I'm happy to go read documentation on how the Minetest implementation of the noise works and its distribution, rather than having you explain this, if you can point me to something.)
Other metals that use the term "common" in the manual include iron, tin, and copper. Tin (in Moreores) seems to have a cluster_scarcity of 7^3 and copper below -64 has a scarcity of 9^3, compared to the 6^3 for zinc. But zinc only spawns if the threshold is above 0.5, so if I'm interpreting that to correctly to mean a 50% chance of spawning, zinc should be marginally less common than tin, but much more common than copper. If the noise is variable enough that 100 nodes distance should basically be enough to make independent chances, then my world must be a HUGE statistical fluke so far... assuming I understand this all correctly.
I agree a setting to disable that non-uniform distribution might be needed - I will try to do that when I can.
The thing is -- I actually really like the idea of "veins" of materials in theory. The problem, from my experience so far, is that these couple metals can really stand in the way of developing certain stages of machines, so someone can be stuck for days or weeks walking around with a pickaxe hoping to find a few nuggets of zinc and chromium to create a few machines and thus make processing a lot easier. Again, this is based off of my sample of mining so far.
(Also, if the idea of veins is taken seriously, they need to be more obvious when you find them. Chromium has a cluster_size of 3, with clust_num_ores of 2 even when it spawns. Even in a region where the Perlin noise exceeds the threshold of 0.55 consistently, one could easily miss such small clusters when digging a tunnel through looking for some. I have no doubt this may be one of the reasons it took me an exceedingly long amount of time before I saw even a single chromium node.)
But perhaps my experience is just a huge statistical fluke, though I've found a couple references further up this thread and elsewhere that others have found these metals to be similarly rare.