marianas and marianasWWII are using a more sophisticated version of the splatmap-technology.
The idea is to blend multiple materials together.
the materials are made up of textures themselves. they consist of color+alpha, NormalMap, MetalnessRoughness-map.
(the materials are in the CloseupTextures files.)
the splatmaps are instructions where to put a piece of material and how much to blend it with the others.
a splatmap is 4 separate greyscale-maps packed into a RGBA dds file. (A=Alpha)
There is a pool of materials available. (36 for marianasWWII)
4 channels means only 4 materials to mix together.
Out of the pool of 36 materials only 4 specificly selected materials can be used at a time for a splatmap.
The mapdesigner decides which 4 would be a good mix for a certain region/asset and "bakes" this decision into the mesh-data.
colorchannel mapping in a splatmap:
R for Material 1
G for Material 2
B for material 3
A for material 4
The position and the brightness of the pixels in a channel dictate how much the material contributes to the endresult.
For the WWII-airfields the 4 selected materials are soil, leaves, shoreline, earth i think.
You could mess with the soil and earth materials in the closseuptextures, but i think they are used heavily in other assets too. but its worth a try.
The mask-textures have also all 4 channels in use, even if it looks like the green-channel is the only one, if you look closely, there is data in R and B too.
The G-channel intensity changes the brightness of the material-mix and in combination with the gradients in the palette-texture the hue and color-saturation i think.
The alpha-channel definitely dictates how the whole thing blends itself with the textures underneath the field.
The R and B channels i dont know at the moment.
the airfield-NormalMaps are for the macro-details for the further-away-view bumpy-ness appearance of course. if more closeup, the materials have their own normalmaps and add their own micro-detail.
