Upgrade Ground Zero terrain material

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):