Bridge Engine – GTA-Style NPC & Vehicle Interaction System

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Bridge Engine – GTA-Style NPC & Vehicle Interaction System

Bridge Engine is a core AI and interaction framework built for Unity developers who want to create dynamic gameplay systems — without complex setups or fragmented architectures.

This is not a full open-world system.

Bridge Engine focuses on the foundation layer: NPC behavior, player interaction, and vehicle systems working together in a unified structure.

🧠 Unified NPC = Player Architecture (Core Advantage)

Bridge Engine uses a true NPC = Player architecture.

This means characters are not split into separate AI and Player systems.

Instead, every character uses the exact same core systems:

• Movement
• Animation
• Interaction
• Camera
• State logic

The only difference is how the character is controlled:

• When controlled by AI → the system generates decisions
• When controlled by Player → the system receives input

Everything else remains identical.

Animations, movement behavior, interaction flow, and state transitions all use the same pipeline.

This allows seamless switching between AI and Player control at runtime without breaking logic, animations, or behavior consistency.

🚗 Vehicle Interaction System

Built for realistic and conflict-free vehicle interaction.

• Real-time vehicle entry & exit
• Door-side awareness (left/right animations)
• Smart seat targeting
• Multi-character support
• Smooth state transitions

🧠 Advanced Seat Manager System

Bridge Engine includes a powerful seat management system designed to prevent chaos when multiple NPCs interact with vehicles.

Each seat follows a clear 3-state logic:

• 🟢 Available → Seat is free and can be used
• 🟡 Reserved → Seat is locked for a specific NPC
• 🔴 Occupied → Seat is taken

This ensures:

• No seat conflicts
• No multiple NPCs targeting the same seat
• Organized and natural vehicle entry behavior

NPCs automatically select the correct door and use the proper animation (left/right side), resulting in realistic and believable interactions.

No teleporting. No snapping. No chaos.

🧭 Custom A* Navigation System (No NavMesh)

Bridge Engine includes a fully custom navigation system:

• Automatic waypoint generation
• Automatic connections (no manual setup)
• Dynamic path recalculation
• Obstacle detection & avoidance
• Performance-aware path updates

No Unity NavMesh required.

Designed for flexible and dynamic gameplay scenarios.

🤖 AI & Interaction Framework

Bridge Engine acts as a central AI system that connects:

• Character movement
• Navigation
• Vehicle interaction
• Group behavior

Behavior dynamically adapts based on:

• Player state (on foot / in vehicle)
• Environment changes
• Target changes

👥 Squad & Group Behavior System

Bridge Engine includes an advanced squad system with player-controlled group commands.

Players can issue commands such as:

• Follow mode
• Hold position

NPCs react intelligently based on distance and context:

• Run when far from the player
• Walk when close
• Adjust speed dynamically

The system also features:

• Dynamic formation system
• Automatic slot assignment
• Context-based spacing
• Obstacle-aware movement
• Smooth transitions between states

NPCs avoid obstacles, maintain formation, and move as a coordinated group without breaking behavior.

This creates natural, responsive, and believable group AI.

🎮 Character & Camera System

• Unified movement for AI and Player
• Built-in camera system
• Player ↔ Vehicle transitions
• Smooth and consistent control flow

⚡ Designed for Real Development

Bridge Engine is built for actual projects, not just demos:

• Rapid gameplay prototyping
• Clean system architecture
• Reduced setup complexity
• Reusable core systems

⚠️ Important Scope (Read Before Purchase)

This is the Core Edition.

It focuses on interaction and AI foundation systems.

It does NOT include:

• Traffic systems
• Large-scale city simulation
• Massive open-world environments

Advanced systems such as traffic, city AI, and dynamic urban features are currently in development and planned for future versions, including Bridge Engine 2.

🎯 Who This Asset Is For

• Developers building AI-driven gameplay systems
• Projects requiring NPC and player interaction
• Vehicle-based gameplay mechanics
• System-focused development workflows
• Teams looking for reusable gameplay architecture

💡 Key Advantages

• Unified NPC = Player architecture
• No NavMesh dependency
• Clean and extensible system design
• Built as a scalable core framework

Note:

• Animation Rigging is required for IK features
• Demo models are placeholders
• Focus is on systems, not visuals