I'm not talking about an entire world, just a section.
You don't need to 'rotate' the pixels as much as just displace them slightly from the center outwards. This wouldn't require wrapping, just a spherical section displacement upwards.
it would always be possible, for small arcs, to generate a height field for this - if you are thinking of 'wrapping' you are stretching the height field, and that's not part of the assumptions behind height fields.
After having said that, it different new feature would be nice if there was a way to generate wrappable edges so that a height field could be wrapped around a sphere with an external program; this would be great for asteroids. But that wasn't really what I was looking for.
Quotea way to 'wrap' a piece of terrain around a sphere
There are three answers for that question. 1) no, it can't be done. because rotating a terrain in that manner would cause the heightmap representation to be inadequate, having two heights per pixel (in the case of mountains near the equator of the sphere) 2) yes, it can be approximated in WM. By simply adding a terrain to that sphere, we move "pixels" up in the chape of the sphere. 3) that is not WM's problem: I can do it in the application that renders the terrain (if it allows that sort of transformation) That's because it would now be a planet, not a heightmap, and WM is not good at planets :)
PS - Just as a small remark, what I mentioned in 2) is what I did in the Leaned Strata macro, which is described in the Tip Of The Month #4 (in the "help" section of //www.world-machine.com).
I'd like to see a way to 'wrap' a piece of terrain around a sphere (preferably oblate) to simulate the horizon curve. I'm not sure this is exactly what you were showing.
Basically, the (rectangular) part of the height field would have params for degrees lat / long and equatorial radius. Even better would be oblate spherids (x/y/z radius) so things like the lumpy moons of Mars could be done. (clearly there are limitations with height fields and odd shaped spheres, but for small amounts of arc it could work).
I'm trying to take MOLA (Mars Altitude data) and make some terrain by adding detail to various files with WM, and I'd like to be able to make the horizon look curved. I can sort of do that with POVRay with iso surfaces, but it would be so much faster to be able to do this with a height field.
Hmmm... I'm really late on this one. It's great to hear about the upcoming new "stuff". I have enough of a handle on WM to be looking forward to v1.0. I was unaware of this community until I followed a link to this subject posted by manleystanley on Terranuts. Good stuff here!
that's the million dollar question. :) V0.99 was released in 3/03, which means it's been almost two years of development now for V1.0, although admittedly the vast majority of that time has not been spent in active development -- the rest of life has kept me from working much on WM. Things have been really picking up in the last while, though.
I'm not going to venture a timeline for it. "When it's done" is the most frustrating answer to hear, but its all I can give right now for fear of promising too much. It will be feature-complete and to bugtesting to the testers group within the next couple months, though.
That explorer mode really looks interesting.. I am eager to try it to see if it makes me more confident with my modelling techniques.. I have a feeling my still is not the best to make a desired terrain, but that may be because I am not seeing the "right tile".. I want to discover if the explorer mode makes things look better than they are, or if I really have a bad still in terrain modelling :)
That river is draining all the water in my mouth.. Very impressive.. It makes me want to use my browser to edit the river path sligtly :P It forces me to think of how would that river look when it found that other coast line.. I am also interested in finding out if the river macro would produce one a single river, or if it would make a random spray or rivers.. I can probably look into it by sneaking inside the river tutorial to check it's behaviour.. Oh well, nice images.. how many tiles are visible there? 3x3 (with us standing on the middle one)?
I think we're actually talking about the same thing, Sethren. The act of going to a larger scale encourages (and requires) layering more noises together.
Maybe a picture would help. Here's a few screen shots from Explorer mode. The world files that produces those terrains are example files in the 1.0 distro.
Upper left, you can see a "Typical" noise based terrain. One perlin generator, all features are more or less one scale, etc.
On the upper right, you can see a terrain that has about 3 noises + sculpting done. There is one perlin that creates the islands/continents, another that creates rolling hills, and the last puts mountain-type terrain in place on the high areas.
Lower left shows the same terrain plus erosion. You can see the grid pattern that results from using erosion in Explorer mode. There are a few things that I might be able to do before 1.0 release that will minimize this, but it is a fundamental problem with heightfield-based effects.
Lower right shows a different (and I think pretty cool) terrain. The river is made using the ol' river technique from the first WM tutorial, but it seems to work alot nicer when you can crank the scale to very high levels.
PS: For what it's worth about the "smoke out of the computer", the framerate was fluid in all those example screenshots. Although granted, on a nice machine...
My apologies... i did not word it correctly... perhaps the explorer mode may get me closer to the entire planets idea rather then just small areas of the terrain... it allmost sounds like what you are saying is that the terrains can be layerd and scaled in such a way to where one can create a more realistic way of displacing the lands and sense there is not often a seam between tiles it sounds like these terrains can get very complex and huge... sounds neat though......
I'm not sure exactly if I get what you mean, BUT...
Once you have Explorer mode at your disposal, you build terrains slightly differently. You tend to start combining vastly different scales of noise, etc, to create the world -- you might have one smooth perlin generator creating continent shapes (run through a Gain device to quickly make it more contrasty), another atop that that creates mountains on the continents, etc. It's a little bit like Mojoworld with only a quarter the Mojo.
It sort of is the missing link in WM, actually - because before, although you could hit the Dice button and get a new random terrain, that was somehow unsatisfying. Now, you create the world and then start flying around until you find some cool features somewhere that you want to see in better detail. Then you just mark the current location so that WM shifts the focus to where you are, hit the build button, and out pops a 512x512 or 1024x1024 or whatever size you want render of that area of the world.
If you have a decent enough computer, you can fly around a pretty damn high resolution world all things considered, and it becomes almost fun just in of itself.
What are the caveats?
#1) Devices that are either global in nature or not scaling-stabilized (Blur, Equalizer, Displacement, Erosion, etc) give results ranging from not-quite-right to bizarre. Erosion actually handles pretty good -- there's often not even a seam between terrain tiles. Blur and Equalizer tend to go all to hell very quickly because of the nature of the effect. So some devices aren't quite right when viewed through the Explore mode.
#2) By and large, WM was not engineered for pedal-to-the-metal speed. With that said, Explorer mode works very fluidly on a AthlonXP 1600 and a good video card. It works best on a 3ghz+ machine with a top end graphics card, as you'd expect. You can set the resolution of the terrain tiles to scale the quality of the graphics. Later, this might be chosen on the fly by the engine itself.
So this (very long) answer is a way of saying that Explorer mode is not Mojoworld. ;) But it IS a very useful tool. It's also a lot of fun. It may change the way you put together WM terrains.