Upgrade Ground Zero terrain material

AGRARIAN_DEVELOPMENT_ROADMAP.md

@@ -946,7 +946,7 @@ looks intentional, grounded, and investor-readable.
 
 Required order:
 
-- [ ] Replace or upgrade the terrain material first so Ground Zero no longer reads as flat tan placeholder ground.
+- [x] Replace or upgrade the terrain material first so Ground Zero no longer reads as flat tan placeholder ground. Rebuilt `M_AGR_GZ_Terrain_CoastalScrub` as a procedural coastal scrub material that blends dry soil, scrub green, and sandy path color families with broad and fine noise, documented the visual baseline, and extended the natural-environment verifier so flat constant-color terrain fails.
 - [ ] Replace or upgrade grasses, shrubs, and trees with believable coastal-scrub vegetation assets, density, color variation, scale variation, and LOD/performance limits.
 - [ ] Replace or upgrade freshwater visuals with readable water surface, edge treatment, bank dressing, reflection/roughness tuning, and collectability cues.
 - [ ] Replace or upgrade character bodies and clothing so selected characters read as realistic near-future post-collapse frontier people rather than template mannequins or proxy stacks.

Docs/Terrain/GroundZeroNaturalEnvironmentPass.md

@@ -6,7 +6,9 @@ space.
 
 ## Scope
 
-- Terrain receives a warm coastal scrub ground material.
+- Terrain receives a procedural coastal scrub terrain material that blends
+  dry soil, scrub green, and sandy path color families with broad and fine
+  noise so Ground Zero does not read as flat tan placeholder ground.
 - Foliage patch instances keep the current prototype meshes but use distinct
   tree, shrub, and dry grass materials.
 - Wood, fiber, stone, and freshwater actors receive distinct first-pass
@@ -48,7 +50,10 @@ space.
 `Scripts/verify_ground_zero_natural_environment_pass.py` checks that the
 materials exist, the landscape uses the terrain material, the foliage actor has
 the expected investor-facing instance counts and material assignments, and
-resource/water actors are visually dressed. It also checks the asset variation
+resource/water actors are visually dressed. It also checks that the terrain
+material contains procedural color breakup rather than a flat constant color:
+noise, blend, and coastal-scrub color-vector expression families must be present
+in the saved material package. It also checks the asset variation
 layer: twenty-three labeled variation actors, at least four mesh silhouettes,
 unique scale profiles, and coverage across tree, bush, grass, rock, and water
 visual families. `Scripts/verify_native_placeholder_meshes.py` checks that playable

Scripts/setup_ground_zero_demo_map.py

@@ -48,6 +48,10 @@ ENVIRONMENT_MATERIALS = {
     "terrain": {
         "path": f"{MATERIAL_FOLDER}/M_AGR_GZ_Terrain_CoastalScrub",
         "color": unreal.LinearColor(0.16, 0.23, 0.12, 1.0),
+        "dry_soil_color": unreal.LinearColor(0.28, 0.24, 0.16, 1.0),
+        "scrub_green_color": unreal.LinearColor(0.12, 0.22, 0.10, 1.0),
+        "sandy_path_color": unreal.LinearColor(0.42, 0.36, 0.23, 1.0),
+        "noise_scale": 42.0,
         "roughness": 0.92,
     },
     "tree": {
@@ -837,11 +841,102 @@ def ensure_environment_materials():
             material.set_editor_property("used_with_instanced_static_meshes", True)
             unreal.MaterialEditingLibrary.recompile_material(material)
             unreal.EditorAssetLibrary.save_asset(spec["path"], only_if_is_dirty=False)
+        if key == "terrain":
+            rebuild_ground_zero_terrain_material(material, spec)
         created_or_loaded[key] = material
 
     return created_or_loaded
 
 
+def set_expression_property(expression, property_name, value):
+    try:
+        expression.set_editor_property(property_name, value)
+        return True
+    except Exception:
+        return False
+
+
+def connect_expression(source, source_output, target, target_input):
+    try:
+        unreal.MaterialEditingLibrary.connect_material_expressions(source, source_output, target, target_input)
+        return True
+    except Exception as exc:
+        unreal.log_warning(f"Could not connect material expression input {target_input}: {exc}")
+        return False
+
+
+def create_constant_color(material, color, x, y):
+    expression = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionConstant3Vector, x, y
+    )
+    expression.set_editor_property("constant", color)
+    return expression
+
+
+def create_constant_scalar(material, value, x, y):
+    expression = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionConstant, x, y
+    )
+    expression.set_editor_property("r", value)
+    return expression
+
+
+def rebuild_ground_zero_terrain_material(material, spec):
+    """Build a simple procedural material so the landscape no longer reads as a flat color."""
+    if hasattr(unreal.MaterialEditingLibrary, "delete_all_material_expressions"):
+        unreal.MaterialEditingLibrary.delete_all_material_expressions(material)
+
+    dry_soil = create_constant_color(material, spec["dry_soil_color"], -900, -260)
+    scrub_green = create_constant_color(material, spec["scrub_green_color"], -900, -80)
+    sandy_path = create_constant_color(material, spec["sandy_path_color"], -900, 100)
+
+    broad_noise = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionNoise, -560, -160
+    )
+    set_expression_property(broad_noise, "scale", spec.get("noise_scale", 42.0))
+    set_expression_property(broad_noise, "quality", 3)
+    set_expression_property(broad_noise, "levels", 5)
+
+    fine_noise = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionNoise, -560, 100
+    )
+    set_expression_property(fine_noise, "scale", 145.0)
+    set_expression_property(fine_noise, "quality", 2)
+    set_expression_property(fine_noise, "levels", 3)
+
+    scrub_blend = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionLinearInterpolate, -260, -180
+    )
+    connect_expression(dry_soil, "", scrub_blend, "A")
+    connect_expression(scrub_green, "", scrub_blend, "B")
+    connect_expression(broad_noise, "", scrub_blend, "Alpha")
+
+    final_blend = unreal.MaterialEditingLibrary.create_material_expression(
+        material, unreal.MaterialExpressionLinearInterpolate, 40, -70
+    )
+    connect_expression(scrub_blend, "", final_blend, "A")
+    connect_expression(sandy_path, "", final_blend, "B")
+    connect_expression(fine_noise, "", final_blend, "Alpha")
+    unreal.MaterialEditingLibrary.connect_material_property(
+        final_blend, "", unreal.MaterialProperty.MP_BASE_COLOR
+    )
+
+    roughness = create_constant_scalar(material, spec["roughness"], -260, 160)
+    unreal.MaterialEditingLibrary.connect_material_property(
+        roughness, "", unreal.MaterialProperty.MP_ROUGHNESS
+    )
+
+    specular = create_constant_scalar(material, 0.18, -260, 260)
+    unreal.MaterialEditingLibrary.connect_material_property(
+        specular, "", unreal.MaterialProperty.MP_SPECULAR
+    )
+
+    material.set_editor_property("use_material_attributes", False)
+    unreal.MaterialEditingLibrary.recompile_material(material)
+    unreal.EditorAssetLibrary.save_asset(spec["path"], only_if_is_dirty=False)
+    unreal.log("Rebuilt Ground Zero terrain material with coastal scrub color variation and procedural noise.")
+
+
 def apply_material_to_actor_meshes(actor, material):
     applied_count = 0
     for component in actor.get_components_by_class(unreal.StaticMeshComponent):

Scripts/verify_ground_zero_natural_environment_pass.py

@@ -82,6 +82,28 @@ def assert_asset(path):
     return asset
 
 
+def verify_terrain_material_is_not_flat(material, failures):
+    project_root = unreal.Paths.convert_relative_path_to_full(unreal.Paths.project_dir())
+    material_package = project_root + "Content/Agrarian/Materials/M_AGR_GZ_Terrain_CoastalScrub.uasset"
+    try:
+        with open(material_package, "rb") as handle:
+            package_bytes = handle.read()
+    except Exception as exc:
+        failures.append(f"could not inspect terrain material package: {exc}")
+        return
+
+    noise_count = package_bytes.count(b"MaterialExpressionNoise")
+    lerp_count = package_bytes.count(b"MaterialExpressionLinearInterpolate")
+    color_count = package_bytes.count(b"MaterialExpressionConstant3Vector")
+
+    if noise_count < 1:
+        failures.append("terrain material should include a noise expression for color breakup")
+    if lerp_count < 1:
+        failures.append("terrain material should include a blend expression instead of a flat base color")
+    if color_count < 1:
+        failures.append("terrain material should include coastal scrub color vector expressions")
+
+
 def main():
     if not unreal.EditorLevelLibrary.load_level(MAP_PATH):
         raise RuntimeError(f"Could not load map: {MAP_PATH}")
@@ -98,6 +120,7 @@ def main():
         expected = MATERIALS["terrain"]
         if assigned != expected:
             failures.append(f"landscape material expected {expected}, got {assigned}")
+    verify_terrain_material_is_not_flat(materials["terrain"], failures)
 
     foliage_actors = [actor for actor in actors if get_actor_label(actor) == FOLIAGE_LABEL]
     if len(foliage_actors) != 1:
@@ -187,8 +210,10 @@ def main():
     roadmap = unreal.Paths.convert_relative_path_to_full(unreal.Paths.project_dir()) + "AGRARIAN_DEVELOPMENT_ROADMAP.md"
     for path, snippet in [
         (docs, "asset variation"),
+        (docs, "procedural coastal scrub terrain material"),
         (roadmap, "[x] Replace grey-box environment presentation with an MVP natural environment pass"),
         (roadmap, "[x] Add first-pass environment asset variation"),
+        (roadmap, "[x] Replace or upgrade the terrain material first so Ground Zero no longer reads as flat tan placeholder ground."),
     ]:
         with open(path, "r", encoding="utf-8") as handle:
             text = handle.read()