built more assets and started playing with foliage painting

addons/terrain_3d/src/operation_builder.gd

@@ -0,0 +1,23 @@
+extends RefCounted
+
+
+const ToolSettings: Script = preload("res://addons/terrain_3d/src/tool_settings.gd")
+
+
+var tool_settings: ToolSettings
+
+
+func is_picking() -> bool:
+	return false
+
+
+func pick(p_global_position: Vector3, p_terrain: Terrain3D) -> void:
+	pass
+
+
+func is_ready() -> bool:
+	return false
+
+
+func apply_operation(editor: Terrain3DEditor, p_global_position: Vector3, p_camera_direction: float) -> void:
+	pass