WIP (sort of tutorial to be) : Climates, applying Geoff's Cookbook at detail (some)

[Pixie]

The ultimate goal will be this (here shown covering only a small area)


In this image I labeled the 5 levels of rain we need later, in order to compute the climates: DRY, LOW, MODERATE, WET and VERY WET (this technique will eventually yield a 6th level - even higher - we can call it INSANELY WET, but treat it as just very wet )

Here's how we transform the previous stack of layers into this:
- set all those layers to "screen" mode (instead of normal) (can please any photoshop/gimp savvy person explain what this means, if necessary?)
- duplicate them (as not to lose your work in the next step and easily go back and quickly correct anything if need be)
- make only the duplicates visible and turn off all other layers in the file (all, including background)
- when you set them to screen mode, they turned very whitish, but now there are areas in the original color and brighter areas where those layers superimpose, right? (just checking)
- merge visible layers

You can name the resulting layer with an appropriate name like "Rain Patterns, July". Once the background is visible again, it might look like this (again, just showing a little area):

The difference between this and the end result above is that I have rounded off the corners. Because the map is supposed to be showing a "likelihood" of rain, transition between levels should always cover the intermediate levels. Depending on the level of detail you want, you may skip this part altogether and adjust later on when we get to the actual climates.

One last thing that can be done, if you want to, is to delete all the parts of the "wetness" map that are over the sea.