Sat down today and tried to wrap my head around making the terrain look more realistic. Before today the terrain looked really smooth, even when the Smoothing Passes were set to zero, almost made the terrain look plastic/fake.
So I read some whitepapers/research posts and came to the conclusion that I can resolve my problem by stacking multiple noise layers together to generate a more rough (but overall still somewhat smooth) terrain noise.
Now what makes this possible? Three things:
Frequency
Amplitude
Offsets
We assign a variable to each of these and allow each layer to have a different Frequency, Amplitude, and Offset. When these layers are generated we then normalize the layers by stacking them and then clamping they're max height.
And to wrap it all up, we scale the height of the generated HeightMap stack by the relative max height value in the widget, run our smoothing passes, and BOOM! realistic terrain. You can really see the difference in using the stacking technique in the image below. It's essentially dialing up the roughness, but with a bit more randomness. We maintain the same overall shape of the terrain thanks to our seed value, but it just helps the overall feel of the terrain be more natural. Albeit random, but natural.
