View Full Version : What to use to make a DEM?

04-05-2008, 12:41 PM
Well, being that my first attempts at a fairly geographically sound world are failing with bryce and ps, i thought i'd open up the floor to suggestion from others.. since it seems many of your know a hell of a lot more about fractals and all such tools. I guess i'll start with what i'm looking for, then let people suggest programs/methods i may get them...

Basically i'm looking to create my entire realm with elevations, and use ArcGIS and raster imaging to do a whole lot of analysis for vegitation, animals, cultures, etc... I'm not to enamoured with fractals (at least my understanding of them) because it seems to be just a random generator for hight maps, where as i'm looking for something thats a bit more geographically sound... such as continental shift, volcanes, and plently of erosion to find out rivers and such. I'd like the results to be anything that can be imported into ArcGIS, the main ones are raster (jpg) or DEM... Since this is sort of a one time thing, as in i won't use it enough for me to justify spending money on purchasing a program, i'd like to be able to do this with freeware or a demo/limited product... resolution is also quite important, since the results in arcGIS will look better the higher the resolution... I've already had tonnes of helm from su_liam and others, but i thought throwing out these questions in a new thread will help get more suggestions (and possibly debate). (and remember i'm a noob to world design, so even though i may know a bit about geographical stuff, i've never really created a world with fractals and such)

Thanks all, i know if any forum anywhere could answer this question its you guys

04-06-2008, 12:51 AM
I once listened to a presentation by Michael Goodchild that included a short introduction on this. Somewhere there is a group who revolves around this. Creating the cause-effect production of topography is not a simple matter. To understand these matters would take an intense introduction to physical geography. Spatially autocorrelated elevations are easier to create via fractals, etc. How about taking a random USGS DEM and then do your analyses? You could compare it to the geography of the real world to see how well they align.

If you want to really get into this method of world creation, look into spatial evolutionary models.

04-06-2008, 01:56 AM
well the analysis isn't really the problem, i mean i'm creating a fake world, so i can put whatever i want in it, i'd just like it to seem realistic in a way, not have mountains sprouting out of nowhere just because... while it'd be great to go through the whole process, of continental drift, volcanoes, etc... i'm fine with drawing out my idea of a map in photoshop, as long as i have some program to run erosion and such on it to make it look realistic... i guess the main thing i need is good realistic erosions... since i want to make rivers and lakes using ArcGIS analysis, and that requires the DEM or raster to have a realistic erosion and such (the problem i ran into with bryce is it make a nice looking erosion at times, but its for visuals, not realism, so the river valleys don't always collect water as they are supposed to and you get a lot of small rivers that go nowhere and stop.. mainly on costal regions, where the river would obviously reach the coast, but it stops before it..

04-06-2008, 04:11 PM
This application might be what you are looking for:


It has the qapability to construct realistic terain and can export terrain in various formats.

Bryce is in my opinion one of the easiest terrain editors to use, but takes forever to constructs large areas (I'm working on a Greayhawk ;). Part two of my Bryce tutorial will cover terrain construction in more detail. Hopefully it will be available in this forum in a week or two.


04-07-2008, 08:30 AM
i like bryce as a tool, but found the erosion and such really lacking in any kind of real form, it seems to be something that either adds or subtracts from whats already there, so you don't end up with realistic erosion... but i've only used it very little, and may be that i don't know what the hell i'm doing :P

as far as worldbuilder, i did download it upon su_liam's mention and tried it out, and well, its a little daunting, as far as trying to stick all the modules together to make something coherant... probably a few tutorials are in order...

04-07-2008, 11:12 AM
Did you see this thread (http://www.cartographersguild.com/showthread.php?p=16630#post16630) on using Wilbur to erode random terrain? It has a pretty nice erosion/river model in it when used properly :)

-Rob A>

04-07-2008, 11:55 AM
I'd seriously considering using the Wilbur Method on my section of the Big Idea Map. Unfortunately it's pretty destructive of existing structures, so I could probably never get my map to fit back in with the neighbors. Everybody would laugh at me... throw rocks and garbage... I don't know. For an original map, though, that kicks serious booty.

There's some stuff I've been doing with grunge brushes with some success. It's pretty hit-or-miss, though. Even more than some of my other off the wall ideas. Also, I don't trust PS to paint in 16-bit.

04-07-2008, 09:34 PM
I did see the tutorial and i have played around with it (it does look sweet huh) but i'm looking at more along the lines of continents, not a random land square, and tho i know i can do that in wilbur, i don't know it enough to get it right... (and when i use high res images, besides taking forever, all the blur/erosion/other values in that tutorial don't really apply... (i tried with my 4096x4096 current map, but i couldn't get erosion to really show up at all...

so if anyone knows how to use it, and could give me a lesson, or point me in the right direction.. that'd be great!

04-08-2008, 10:42 AM
i'd have to say with waldronate's new wilbur tutorial (http://www.cartographersguild.com/showthread.php?p=16723#post16723) (were you reading my thread and decided to help me? seriously.. couldn't come at a better time!) I'd have to say wilbur is my best bet i've seen so far... i'll be playing around with it and seeing if i can come up with something... thanks again waldronate!