Make continent-scale heightmap based on existing coastline

[Amy Worrall]

I just realised in my previous message, I didn't talk about what I want to use this map for.

I actually want the ability to make many maps. That's one reason I've got my own software in the pipeline. Maybe we want an Empire-wide military report -- I could render out a copy of the full map, with territories coloured by ownership and disputed borders highlighted. Or maybe we want something that shows the locations of all fortifications in one region: render something a bit more zoomed in, with icons for the forts.

My largest Empire-wide maps will be printed at up to A1 size, but I imagine any regional ones I do would be smaller.

Thus, I need a height map that'll work as a background for anything from the whole Empire-wide map to a map of an individual territory to a region within a territory. However, since the height map is just a background feature for many of the maps, it doesn't have to be super detailed. I'd be happy enough if it could convey where was mountain vs hills vs plains in the zoomed in maps.

[waldronate]

How big do you expect your highest detail map to be? What surveying technology are they using? One of the great joys of most pre-1800s maps are the fantastic distortions in different maps done by different publishers.

[Naima]

I'm trying to make a realistic height map based on a fantasy sketch map. I know the shape of the coastline, the size, and details at the level of "there are mountains here" and "there are plains here". I know the locations of some rivers, and some other features, but there's plenty of scope to add additional stuff.

What software can I use that can:

1. Work at that scale (I need a map of size about 1500x1500 miles)
2. Let me start with my known coastline
3. Will help me build mountains in the places I want them, etc, adding realistic erosion.

I don't need 3D rendering. (Well, I want to do some, but I'm happy to do that in a different program if necessary -- I definitely want access to the 2D height map either way!)

I make my maps maximum size 24kx10k more or less and If i go above I can't handle in PS due to my PC specs I guess, I use Photoshop , worldmachine, wilbur, fractal terrains too.