NAVMESH_AND_PATHFINDING

 

 

 

Based on the context of this image—which displays a list of standard Unreal Engine 5 (or 4) Blueprint nodes related to AI navigation—the "missing data" refers to the essential components and settings required to actually make these specific nodes work.

While the image lists the commands (functions), it is missing the infrastructure (components and volumes) and context.

Here is the critical data missing from this overview:

1. The Essential Setup (The "Where")

The most glaring omission is the volume required to generate the navigation mesh in the first place. None of the nodes listed in the image will function without:

• NavMeshBoundsVolume: You must place this volume in the level and scale it to cover the walkable area. Without this, there is no "NavMesh" for the Project Point or Random Reachable Point nodes to query.
• RecastNavMesh: The actual data object generated inside the bounds volume that defines geometry, slope angles, and agent radius.

2. The Agent/Controller (The "Who")

Most of these nodes (specifically AI Move To) require a specific owner to function.

• AIController: Standard "Player Controllers" cannot use AI Move To easily. The character usually needs to be possessed by an AIController or DetourCrowdAIController.
• CharacterMovementComponent: For these nodes to move an actor, that actor usually needs a movement component configured with NavMeshWalking capabilities.

3. Advanced Navigation Data (The "Nuance")

The nodes shown are for basic "A to B" movement on a flat plane. A complete NavMesh system usually includes:

• Nav Link Proxy: Data required for AI to jump off ledges, climb ladders, or traverse gaps (connecting two disconnected NavMeshes).
• Nav Modifier Volume: Data used to define "expensive" areas (e.g., mud or fire) that the AI should try to avoid but can walk through if necessary.
• Nav Area Classes: The specific data definitions for those modifiers (e.g., NavArea_Null to block pathing invisibly).

4. Asynchronous/Event Data

The image shows function names, but misses the execution flow data specific to AI Move To.

• On Success / On Fail Pins: Unlike Simple Move to Location, the AI Move To node is a "Latent Action." It has missing visual context regarding when the movement is finished. It requires event handling to know when the AI has actually reached the destination.

Summary

If you were trying to build this system based only on this image, you would fail because you would have the instructions (nodes) but not the map (NavMeshBoundsVolume) or the driver (AIController).

 

 

 

 

 

 

To create a functional AI system in Unreal Engine, you need to combine the Action Nodes (from your image) with the Structural Components (the missing data).

Here is the final summary of the complete "AI Navigation Stack," ordered from the ground up:

1. The Environment (The "Map")

Before any node from your image can fire, the level must define where movement is physically possible.

• NavMeshBoundsVolume: This is the most critical missing piece. You must drag this volume into your level and scale it to encompass the playable area. Pressing P in the editor toggles the green visualization of this mesh.
• RecastNavMesh: When the volume is placed, Unreal automatically generates this actor. It holds the data for agent height, radius, and slope limits (e.g., ensuring an AI doesn't try to walk up a 90-degree wall).

2. The Brain (The "Driver")

The nodes in your image (specifically AI Move To) generally do not work on a standard PlayerController. They require a dedicated AI driver.

• AIController: Your NPC character must be set to be "Auto Possessed by AI" (either "Placed in World" or "Spawned").
• DetourCrowdAIController: If you have many units, you replace the standard AIController with this to handle collision avoidance so units don't bunch up into a single point.

3. The Instruction (The Image Data)

This is where the nodes you uploaded fit into the stack. Once the Map and Driver are present, these nodes act as the commands:

• Navigation Queries: Get Random Reachable Point in Radius and Project Point to Navigation query the NavMesh (Layer 1) to find valid coordinates.
• Movement Commands: AI Move To tells the AIController (Layer 2) to push the Pawn toward those coordinates.

4. The Logic Flow (The "Result")

The final missing piece is handling the outcome of the movement.

• Latent Execution: AI Move To is a latent node (indicated by the clock icon usually found on it). It runs in the background. You must use the On Success and On Fail execution pins to determine what happens next (e.g., if the AI gets stuck, does it try again or play an idle animation?).
• Nav Link Proxies: If the AI needs to jump a gap or open a door, you must place Nav Link Proxies in the world, which tell the system, "This isn't a flat floor, but you can cross it if you play this specific animation."

Summary Checklist

If you are debugging why your AI won't move, check this stack in order:

1. Is there Green? (Is NavMeshBoundsVolume present and built?)
2. Is there a Brain? (Is the actor possessed by an AIController?)
3. Is the Destination Valid? (Does Project Point to Navigation return a valid boolean?)
4. Is the Command Firing? (Are you calling AI Move To?)

Would you like a screenshot example of how to set up the AIController properly to use these nodes?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This image is a significant improvement over the previous one because it correctly identifies the Hardware (NavMeshBoundsVolume) and the Driver (AIController).

However, to make this system actually work in a real project (like your violin app or a game), it is missing the Configuration Data and the Decision Structure.

Here is the missing data required to bridge the gap between this summary and a functional system:

1. The "Invisible" Geometry Data

The image mentions the NavMeshBoundsVolume and the "walkable surface," but it misses the specific settings that define who can walk there. This data lives in the RecastNavMesh-Default actor (which is auto-created but not mentioned):

• Agent Radius & Height: If your AI character is 40cm wide but the NavMesh assumes 35cm, your AI will get stuck on corners. This data must match your Character Movement Component.
• Cell Size: The resolution of the floor. If this is too large, the AI cannot navigate tight spaces or through small doorways.

2. The Decision Structure (Behavior Trees)

The image lists AI Move To as the "primary function." In practice, running AI Move To directly on a Blueprint graph (Tick or Event) is bad practice for anything complex.

• Behavior Tree (BT) & Blackboard (BB): The missing data is the structure that decides when to move. A proper system uses a Blackboard to store the "Target Location" vector and a Behavior Tree to execute the Move command only when necessary.

3. "True" Obstacle Avoidance

The image claims AI Move To handles "obstacle avoidance." This is only partially true—it handles static world geometry (walls). It does not handle dynamic objects (other AIs moving) well.

• DetourCrowdAIController: To stop AIs from walking into each other, you usually need to swap the standard AIController for a DetourCrowdAIController (or enable RVO Avoidance on the movement component). The standard controller listed in the image will often result in AIs piling up on top of each other.

4. Environmental Nuance (NavModifiers)

The system shown treats the world as binary: Walkable or Not Walkable.

• NavModifierVolumes: You often need data to define "high cost" areas (like mud, fire, or a steep hill) that the AI should avoid unless necessary. This is done via Nav Area Classes, which are missing from this summary.

Summary of Missing "Level 2" Data

Missing Component	Why it's needed
RecastNavMesh Settings	Defines the physical size of the AI agent (Radius/Height).
Behavior Tree / Blackboard	Stores variables and manages the logic flow (Brain).
DetourCrowdAIController	Handles collision avoidance with other moving entities.
NavModifierVolume	Defines "costly" ground (e.g., "don't walk here unless you have to").

 

 

 

 

 

To create a fully functional, "production-ready" AI system in Unreal Engine 5, you must combine the basic elements shown in your image with the critical configuration data that was missing.

Here is the final, consolidated summary of the complete AI Navigation Stack:

1. The Physical Foundation (The "Body")

The image correctly identifies the NavMeshBoundsVolume as the starting point, but the system is incomplete without the specific agent data.

• NavMeshBoundsVolume: Defines the area where navigation is possible.
• RecastNavMesh (Missing Data): Defines the agent's physical limits. You must configure Agent Radius, Agent Height, and Step Height in your Project Settings. Without this, your AI will try to walk through doors that are too narrow or get stuck on small bumps.

2. The Logic Structure (The "Brain")

The image lists the AIController as a requirement, but fails to mention how that controller makes decisions.

• AIController: The class that possesses the pawn.
• Behavior Tree & Blackboard (Missing Data): Instead of running logic in the Event Graph (which is messy), you should use a Blackboard to store data (like "Target Location") and a Behavior Tree to execute logic (e.g., "Patrol" vs. "Chase"). This separates decision making from movement.

3. The Movement Execution (The "Action")

The image highlights AI Move To as the primary function, but this node alone lacks dynamic awareness.

• AI Move To: Handles the pathfinding calculation from Point A to Point B on static geometry.
• DetourCrowdAIController (Missing Data): To prevent AIs from walking into each other, you should use this specific controller class (or enable RVO Avoidance). This adds dynamic obstacle avoidance to the standard pathfinding.

4. Environmental Nuance (The "Context")

The image implies a binary world (walkable vs. not walkable), but real environments are complex.

• NavModifiers & Nav Areas (Missing Data): You need these to define "high cost" areas. For example, a fire pit might be "technically" walkable, but you mark it with a high cost so the AI will choose a longer path around it unless forced.

Final Checklist for a Working System

If you are building this for your violin app or a game project, ensure you have all four layers:

1. Bounds: Is the NavMeshBoundsVolume covering the floor?
2. Settings: Does the generated RecastNavMesh match your character's capsule size?
3. Brain: Is the AIController running a Behavior Tree?
4. Avoidance: Is the controller set to DetourCrowdAIController (for multiple agents)?