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Soixante
01-15-2009, 11:00 PM
I'm not sure if this is the right section to post this in, if not please move.

I'm trying to find a method to do good-looking rivers on a continental scale, without having to do them manually. Something like the rivers here (http://www.jezelf.co.uk/tutorials_map01.htm) (scroll down to rivers), in terms of looks. But hopefully there's an even easier way to do this than that proposed on that site.

Anyone know how?

Hoel
01-15-2009, 11:10 PM
The easiest way I can think of is hand drawing them with a tablet. It's fast, and with a bit of practice, easy. Plus you get good control of where they start and finish.
I might be a bit biased towards hand drawing, but i think almost everything looks better when you do it by hand, coastlines, rivers, lakes, height and so on. It's all about controlling the map.
Generating coastlines can be good sometimes, aspecially when you can adapt the actual use of the map to the map itself. If i make a map before writing a campaign about it, it doesn't matter.

Asharad
01-16-2009, 12:16 AM
Wilbur can do some pretty rivers, but I'm not sure how to move then to my own maps.

Nomadic
01-16-2009, 01:55 AM
The easiest way I can think of is hand drawing them with a tablet. It's fast, and with a bit of practice, easy. Plus you get good control of where they start and finish.
I might be a bit biased towards hand drawing, but i think almost everything looks better when you do it by hand, coastlines, rivers, lakes, height and so on. It's all about controlling the map.
Generating coastlines can be good sometimes, aspecially when you can adapt the actual use of the map to the map itself. If i make a map before writing a campaign about it, it doesn't matter.

I agree. I have found that with the technique I use for random generation, it still turns out better if I take bits and pieces and move them around to my liking. The human mind still outperforms any PC fractal program.

If you really want help with random rivers then there are two things that I sometimes use that might help. The first one is the quick way when I just need a river fast. For that you do a cloud noise filter (plus difference clouds if you're using photoshop) then use layers or thresholds to get everything white except for the thin twisty black lines. After that you just slice out sections and plop them down wherever looks good and then fill and bevel it so it looks river like.

The other way is a bit longer but it is easy and looks good. For that you will want to make a height map for your continent (there are plenty of tutorials around here that talk about how to do that). Then once you have got it to your liking you plop it down and trace the contours of the rivers based on the slope of the land. I find that if you do a mid blue (a bit lighter than the ocean) and stroke it with a slightly lighter blue it gives you a nice look. After that you blur it just a little (enough to merge the stroke with the river lines) and viola.

Redrobes
01-16-2009, 08:33 AM
Getting rivers in approximately the right place is fairly easy. To do it automatically with a PC is pretty hard.

Firstly - take a look through this little tut. I wrote this but its actually a collection of ideas and stuff we have talked about on these boards for a while by many people.

http://www.cartographersguild.com/showthread.php?t=3822

I write an app which calculates rivers automatically which is the GeoTerSys link in my sig - theres some movies on there to show what its doing. But the app is one of several trying to solve this very hard problem. Its a LOT harder than it first appears. Obviously water flows downhill and we can program that easily but that's not the end of the issue. It gets complicated from there and thats where the real fight is taking place.

Waldronate (joe) on these boards writes Wilbur which is what Jezelf (also on these boards) was using to get his rivers out of his terrain. If you look in my sig again there is a keyword index. Look up Wilbur in there and Joe has done a few tutorials for it and shows how to do the rivers using it.

Apps like Wilbur, mine, some of the GIS apps and the odd one or two more are the only options in this area right now and since Wilbur is kindly downloadable for free then I would suggest that would be a good starting point.

Korash
01-16-2009, 07:14 PM
there is also this little tut

http://www.cartographersguild.com/showthread.php?t=2711

Talroth
01-16-2009, 09:06 PM
One way I've done rivers is to use a huge brush, 5 to 10 times the size of the river I want. From there I make a new layers and lay out the rough shape of the rivers, and then I'll take the eraser tool and refine them. This makes doing rivers with a mouse far easier, if slightly slower than doing them with a stylus.

Bedwyr
01-16-2009, 09:12 PM
For doing em manually, I use a kind of "wandering zen" application. You remember Inigo from Princess Bride, how he used his sword as a goofy dowsing rod and found the torture chamber? Same idea. I start gently winding and wiggling east... and there's a mountain to the southeast sooo I zzzoooom away to the north and gently wind... until I see another obstacle aaaannd I zzzooom away from there and keep winding and curving my way to the sea.


And then I make happy trees. Lots of happy trees. :)

monks
01-17-2009, 12:24 AM
well really when you are making rivers you are also making happy tress then as well. haha. Look at their morphology, very similar.
I think Robes and Joe (Slayton) have some of the best experience and results with this. SeerBlue did some good work on this also with ME-DEM.
Here's an idea. Try and run a completely procedural river creation on a terrain. Then mark out where the lay of the land is taking them. Then erase the river processes. With this knowledge, then model you primary rivers (only) manually. Then run the procedurals again. The procedurals will not erase the primary rivers only accentuate them. The two should hook up pretty well in my experience. This way you combine the best of both worlds. Primary rivers important for your game world manually with all the time consuming little rivers procedurally.

monks

Nomadic
01-17-2009, 01:24 AM
And then I make happy trees. Lots of happy trees. :)


The Ross is strong with you my child.

Ascension
01-17-2009, 02:25 AM
Love the Ross.

Soixante
01-20-2009, 06:14 AM
Thanks all for your input. It's going to take some time to try all this out. :)