Quote Originally Posted by Guldaroth View Post
But, for your question, I talked with a geologist about such a similar matter. He said to me that the erosion patterns could be approximate this way: In the beginning the erosion is quite everywhere the same. What really matters is the geological soil. On a long scale it tends to diverge from regions to regions. For exemple after at a certain time, a region will be quite flat because of its soil which is far more tender than another region. And so you've got the first step to define your rainfall patterns! I think you'll have to work those question together.
I hope I was understandable enough...
If i understand you, you are saying i shouldn't worry about eroding high rainfall and low rainfall areas differently, because climate and rain patterns vary, and at some point in the past all the different parts of the planet will have gotten some rainfall. Is that right?


Quote Originally Posted by Ascension View Post
If you have access to DEMs then B is the way to go...just copy n paste and blur n paint until they fit seamlessly. Otherwise you're with the rest of us looking for a way to emulate a DEM...finding some techniques or doing it by hand. On the erosion, it shouldn't matter too much for a world map because you can only get so detailed in the image. By and large the rest of us just use informed guesswork and make it up as we go.
Is there any different between a "DEM" and a "bump map", like these: (1. Terrestrial elevation data)? He's labeled the 16bit versions as "DEM"s, and the 8bit version as a "bump map", but i would have called them both "bump maps". Maybe you would call them both DEMs?

16,200 pixels wide is the largest i've been able to find a bump map, and while it's 4x bigger than my map, would anyone recommend working from something larger (if it's available somewhere)? Seems like my elevation might be much less obviously part of Ethiopia (for instance), if i copy/pasted a piece that was more zoomed in. Of course the scale of the features would have been changed, but i expect such geologic features are "fractal" enough, that they look similar at different scales.