My apologies for being lazy, monks. Here are the relevant tiles (in jpg format to save space) so you can see 1) what I'm talking about re: the "striations", and 2) the before and after using PSP's stretch function.
Before and after...
I really like the results, speaking from in-game of course. As I said, the image on the left produced plains west of the Misty Mountains at a height around 100 blocks (out of 255) with the cloud level only 28 blocks higher. The image on the right produced plains at around 50 blocks. Doesn't sound like much but it makes a huge visual difference in game.
Also note the striations in the Misty Mountain range. Notably the long, uninterrupted valley extending from the top of the tile all the way down to Isengard. In addition the spurs almost seem like they're uniform in angle. To a large degree at least, they appear to mostly extend from the ridges in the same directions. Contrast that to
this picture of a RL mountain range in Colorado, where the spurs seem more random in formation. Or do they? lol maybe it's just me. Feedback appreciated.
For the record, in game it looks nice. I'm not gonna' lie. Just something bothers me and it may just be me.
Here are some in-game screens of the area where the west gate of Moria should be. I've added some trees and a door to locate it...
The last is a pic of the minimap of the area. Sorry I haven't explored all of it yet. It shows where the west gate would be, and the east gate which would be a little to the west of the lake on the right (Kheled Zharam?). Just noticed it has some artifacts on the west end. I just imported part of this one DEM tile, so that's where Minecraft started auto-generating extra terrain.
The 2nd screenshot shows a bit of the scale standing at gate level (height around 70) looking at the peak above (height around 180). The Sirannon (river flowing down from the west gate) was just a placeholder job. I'm going to set my map in the 3rd age, around the time of the Fellowship for continuity-sake.
Of course the dirt/mossy stone/stone/snow on the mountains leaves a lot to be desired. I just picked some sensible height values and made it use those blocks if the map at a given spot was >= that height. I'd like to eventually at least attempt something in the vein of
this gentleman's fine work as far as detailing the mountains. This guy is just awesome. Note that he's using a custom texture pack that gives more variations in the stone blocks, but still! Sweet!
Enough for now. Laters!
EDIT: Forgot to answer your questions. World Painter takes the BMP, which is an 8 bit (greyscale) heightmap, and imports it straight into a minecraft format. If in the BMP a pixel = 0 (solid black), then the block at that x/y gets placed at height=0. If the pixel = 255 (solid white) then the block at that spot gets placed at height=255. So there's no sampling per se. What determines WHAT block gets placed at that height is up to you on import. As I mentioned I chose a handful of parameters that basically takes any height less than say 100 and makes it grass, anything from say 100-128 would be dirt, 129-150 would become mossy stone, etc.
But yeah, having only 256 possible heights results in some low fidelity landscape. Quite fun and playable though!
As far as cutting out some buildings from minecraft maps...yes indeed. That's exactly what I was doing prior to getting DEM data from you guys. I was taking mapmaker's works that they've made publicly available (
http://planetminecraft.com for example), opening them up in MC Edit (another Minecraft world editing tool - think less paint, more CAD) and cut and pasting structures out of them. I would then import the structure into the part of the ME map I wanted to put it in. All super easy to do stuff, just time consuming especially on low end hardware.