Adjustments are used to influence the output of a single layer. They let you, for example:
increase the contrast of a layer
invert the layer
add or subtract from the layer
The effect of an adjustment is only applied to the layer it is clipped to, and won't affect the rest of the layer stack.
Adjustments are located at the bottom of each layer, and the adjustment row has these options (from left to right):
Show adjustments: Whether to show the adjustments UI.
Add adjustment: Add a new adjustment to this layer.
Move adjustment up/down: Move the selected adjustment up or down in the stack.
Remove adjustment: Remove the selected adjustment from the stack.
Each adjustment can be selected by clicking the pointer icon on it's left.
Changing the contrast of a layer
1. Let's say we have a layer stack like the one pictured, that uses a slope layer to select only flat areas of the terrain, and then a height layer with the blend mode set to "multiply" to mask that to only the high points of the mesh:
Make sure to set the height blend mode to multiply.
2. But now the effect of the slope layer isn't very well-defined, so we need to increase the contrast of it. However, if we just add a contrast layer below the height one, this will affect all the layers, and give an undesirable result:
We don't want any of the steep areas to be red...
3. To fix this, we can instead add the color ramp layer as an adjustment to the slope layer. This means that it will only affect the slope layer, and none of the others, before or after, allowing you to tune it correctly. You can also add one to the height adjustment for even more control:
Now the steep areas are still blue, and there's a lot more contrast between steep and flat :)
Normalizing a layer
1. Some layers output values that go beyond the normal zero to one range. For example, the point proximity layer, outputs the distance of each vertex from a point in space, which can obviously result in values much greater than one:
Here, the red values are much greater than one
2. To fix this, we can use the "Normalize" adjustment. It takes all values on the mesh, and squashes or stretches them to fit in a zero to one range:
Now the values are much easier to work with!