Hallo,
terrain textures often have some real world light source casting shadows baked into the image data. Like in this example (with slightly too large stones):
So there are areas that are a) in engine-generated shadow and/or b) areas that are in baked image data shadow. This might make up too much of contrast within engine-aware shadow areas.
No wonder, of course, with such a simple setup like the one I’ve made here
but the material-exit node doesn’t seem to have a “engine should apply that much of direct sunlight shadow even if it thinks the area is in sunlight”-pin (for the default-lit material type at least).
Also, the terrain documentation strongly recommends to not use much more than 3 detail textures, without mentioning reasons for that. IIRC, even my GF2MX (with CPU vertex pipeline) had so many texture samplers, and I have a strong preference to work with something like 8. Any probs to expect from that?