Quote from: Chris on December 08, 2015, 11:41:03 PM
The lead-in octaves for the Alpine shader, how does one know how large the main features are and does it multiply the Feature scale itself for every octave added?
When "Lead-in octaves" = 0, the largest cells occur at the scale of "Feature scale".
Additional lead-in octaves add cells that are larger than "Feature scale". How much larger depends on "Scale step" on the Settings tab (although this setting also controls the scale ratio of smaller octaves as well as largers ones).
For example, if "Feature scale" = 4000 and "Scale step" = 3:
Lead-in octaves 0 => largest cells are 4000 metres across.
Lead-in octaves 1 => largest cells are 12000 metres across.
Lead-in octaves 2 => largest cells are 36000 metres across.
... etc.
Lead-in octave cells have the same displacement amplitude as the cells that occur at the "Feature scale", and they also contribute to the flow of smaller cells in a different kind of way. So when considering how steep the mountains are, where you want to think about the relationship between amplitude and scale, it is better to think about the relationship between "Displacement amplitude" and "Feature scale", but not the scale of lead-in octaves, and that's why I chose to parameterise it this way.
Matt