QED42 was kind enough to ask how I made the heightmap which I created for my current Lite Challenge map, using Gaea. I decided to post this here, as a more appropriate place, and perhaps a place where I (and others if interested) can post ideas on using Gaea for fantasy maps as I continue to improve my methods and figure out new tricks.
A couple BIG disclaimers before I dive in:
1. I am still very new to Gaea, so I am sure I am missing better ways to approach things and adding unnecessary steps. Please chime in if you see a better way to do something!
2. Some of the things I do here may be difficult or impossible to do with the free version of Gaea. That said, the free version is still quite powerful and if you're willing to pay for a terrain program, the Indie and professional versions of Gaea are among the cheapest.
Before I dive in, here's the heightmap I made for the Lite Challenge (far from perfect I know):
Combined heightmap.png
Here's my somewhat messy node chart which I used to create this heightmap.
Node chart.png
STEPS
1. The cool thing about using Gaea for fantasy mapping, is that you can upload the outline of your landmass using the File node. Adjust the settings on the File node until it fits what you're looking for probably keep the height relatively low), then set the node to act as a mask.
2. The next steps are to build your terrain. I won't go into the basics of "how to use Gaea" here, but there are plenty of tutorials out there. The main thing to note, is that all of the nodes you use, whether primitives, pre-sets, LookDev, etc., all should link back to the file mask. Another tip, which is more general, is that when building a terrain from scratch rather than using presets, it can help to you Additiona and Overlay modes on the Combine nodes as well as the regular blending of Normal mode.
3. Erosion comes next. Once again, I won't get into the basic Gaea "how too's", but you can see from my node chart that I used a liberal smattering of different types of erosion along with river nodes. Flow nodes could be used as well.
4. This step isn't necessary, but I chose to draw a manual Mask using the Mask node to highlight the peaks in my landmass, which lets you draw the mask free hand. You can see the original hand drawn mask I used below. Then, as you can see in the node chart, I combined some primitives and Lookdev nodes to create sharper and more rugged mountains.
Mask.png
5. Finally I set the resolution 4k and downloaded the heightmap at high definition (I was working at 0.5k which is generally plenty high for good working quality, and your computer will run with almost no delays for updating).
6. Another unnecessary, but potentially useful step, which I did was to tweak the heightmap slightly in Gimp. I did this primarily to adjust the color levels and make the terrain pop a bit more. This would probably have been unnecessary if I was better at using Gaea
That's all there was too it. As I said initially, I am sure there are even better ways to do this, and many ways in which I could improve on this method - especially the rivers. That said, I plan to continue improving the method and I hope people will leave comments if they also are testing out Gaea and find new and improved methods for making fantasy heightmaps!