Object Properties in Tiled

Objects in Tiled are used to define interactive elements, spawn points, collision areas, and game logic triggers. Olympe Engine uses custom properties on objects to configure entity behavior.

Object Types

Spawn Points

Define where entities appear in the game world.

Player Spawn

{
  "type": "PlayerSpawn",
  "properties": {
    "spawnId": "player_start",
    "facing": "right"
  }
}

NPC Spawn

{
  "type": "NPCSpawn",
  "properties": {
    "prefabPath": "Blueprints/NPCs/Villager.json",
    "behaviorTree": "Blueprints/BehaviorTrees/Wander.json",
    "wanderRadius": 100
  }
}

Enemy Spawn

{
  "type": "EnemySpawn",
  "properties": {
    "prefabPath": "Blueprints/Enemies/Goblin.json",
    "behaviorTree": "Blueprints/BehaviorTrees/Patrol.json",
    "aggressive": true,
    "detectionRadius": 150
  }
}

Common Object Properties

Identity Properties

name (string): Unique identifier for the object
tag (string): Grouping tag for similar objects
entityType (string): Entity classification (Player, NPC, Enemy, Item, etc.)

Transform Properties

x, y (float): Position in world coordinates
width, height (float): Object dimensions
rotation (float): Rotation in degrees

Prefab Properties

prefabPath (string): Path to prefab JSON file

Example: "Blueprints/Items/HealthPotion.json"

AI Properties

behaviorTree (string): Path to behavior tree JSON
wanderRadius (float): Maximum distance for wander behavior
patrolPoints (string): Comma-separated patrol waypoint names
aggressive (bool): Whether entity attacks on sight

Physics Properties

static (bool): Whether object is immovable
solid (bool): Whether object blocks movement
sensor (bool): Trigger without blocking (useful for zones)

Object Property Examples

Item Spawn

Create an item that can be picked up:

// In Tiled object layer:
{
  "type": "ItemSpawn",
  "name": "health_potion_01",
  "properties": {
    "prefabPath": "Blueprints/Items/HealthPotion.json",
    "respawnable": true,
    "respawnTime": 30.0
  }
}

Trigger Zone

Create an area that triggers events:

// In Tiled object layer:
{
  "type": "TriggerZone",
  "name": "dungeon_entrance",
  "properties": {
    "sensor": true,
    "onEnter": "LoadDungeon",
    "targetMap": "Maps/Dungeon01.tmj"
  }
}

Waypoint

Define navigation waypoints:

// In Tiled object layer:
{
  "type": "Waypoint",
  "name": "patrol_point_1",
  "properties": {
    "waypointGroup": "main_patrol",
    "waitTime": 2.0
  }
}

Loading Objects in Code

Objects are automatically loaded from Tiled maps:

// TiledMapLoader processes objects during map loading
void World::LoadLevel(const std::string& levelPath) {
    LevelDefinition levelDef = TiledToOlympe::LoadLevel(levelPath);
    
    // Process all objects in object layers
    for (const auto& layer : levelDef.objectLayers) {
        for (const auto& object : layer.objects) {
            CreateEntityFromObject(object);
        }
    }
}

// Custom object processing
void CreateEntityFromObject(const TiledObject& object) {
    if (object.type == "NPCSpawn") {
        EntityID npc = PrefabFactory::CreateFromFile(
            object.GetProperty("prefabPath")
        );
        
        // Set position from object coordinates
        Position_data pos;
        pos.position = Vector(object.x, object.y, 0);
        World::Get().AddComponent<Position_data>(npc, pos);
        
        // Add AI behavior
        std::string btPath = object.GetProperty("behaviorTree");
        BehaviorTree::LoadForEntity(npc, btPath);
    }
}

Object Property Types

Tiled supports various property types that Olympe Engine can read:

Type	Tiled Type	C++ Type	Usage
String	string	std::string	Paths, names, identifiers
Integer	int	int	Counts, IDs, enum values
Float	float	float	Positions, radii, timers
Boolean	bool	bool	Flags, toggles
Color	color	SDL_Color	Tint colors, debug colors
File	file	std::string	File paths (relative to project)
Object Reference	object	int (object ID)	References to other objects

Advanced Object Patterns

Linked Objects

Create relationships between objects:

// Object A
{
  "name": "lever_01",
  "type": "Switch",
  "properties": {
    "targetObject": "gate_01"  // Reference by name
  }
}

// Object B
{
  "name": "gate_01",
  "type": "Gate",
  "properties": {
    "locked": true
  }
}

Prefab Overrides

Override prefab properties per-instance:

{
  "type": "NPCSpawn",
  "properties": {
    "prefabPath": "Blueprints/NPCs/Merchant.json",
    // Override specific component values
    "Name": "Bob the Blacksmith",
    "Health.maxHealth": 150,
    "Sprite.tint": "#FF0000"
  }
}

Best Practices

Naming Conventions

Use snake_case for object names
Prefix with type: npc_villager_01, item_sword_rare
Include sequence numbers for multiples

Layer Organization

Put different object types on separate layers
Name layers clearly: "Spawns_NPCs", "Spawns_Items", "Triggers"
Use layer visibility to manage complexity

Property Documentation

Add comments in Tiled's object properties
Document custom properties in your prefabs
Keep a property reference document

Performance Considerations

Use object pooling for frequently spawned objects
Mark static objects as static: true
Limit the number of objects with AI behavior

Debugging Objects

Enable object debug rendering:

// In GameEngine initialization
World::Get().SetDebugRenderObjects(true);

// Objects will render with:
// - Bounding boxes
// - Names
// - Type labels
// - Property icons

Property Validation

Olympe Engine validates object properties at load time:

// Example validation in code
bool ValidateObjectProperties(const TiledObject& obj) {
    if (obj.type == "NPCSpawn") {
        if (!obj.HasProperty("prefabPath")) {
            LogError("NPCSpawn missing required 'prefabPath' property");
            return false;
        }
        
        // Validate path exists
        std::string path = obj.GetProperty("prefabPath");
        if (!FileExists(path)) {
            LogError("Prefab not found: " + path);
            return false;
        }
    }
    return true;
}

Object Types​

Spawn Points​

Player Spawn​

NPC Spawn​

Enemy Spawn​

Common Object Properties​

Identity Properties​

Transform Properties​

Prefab Properties​

AI Properties​

Physics Properties​

Object Property Examples​

Item Spawn​

Trigger Zone​

Waypoint​

Loading Objects in Code​

Object Property Types​

Advanced Object Patterns​

Linked Objects​

Prefab Overrides​

Best Practices​

Naming Conventions​

Layer Organization​

Property Documentation​

Performance Considerations​

Debugging Objects​

Property Validation​

See Also​