Telepathy Implementation V1 - Part 1

Overview

This is the first of a multipart series showcasing my solution for the telepathy ability I described in a previous planning post. The system, even in this prototype format, includes multiple Blueprints, graphs, post-processing effects, and audio logic, so I’ve chosen to split it into parts for easier consumption.

It can be modified to work as a standalone system. But for my purposes, I designed it to work with the Narrative Pro 2 framework plugin and GAS. If you want to replicate it as-is, you would need both in your project.

The four objects I’m going to go through in this post are BPC_AmbientThoughtsManager, BPC_NPC_Thoughts, BP_MindRead_Thoughts_Actor, and PDA_AmbientThoughts. These objects are responsible for storing and managing an NPC’s ambient thoughts.

In simple terms, the NPC owns a PDA_AmbientThoughts data asset, a BP_MindRead_Thoughts_Actor, and a BPC_NPC_Thoughts component. The data asset is where I set the information for each NPC, such as their thought audio, subtitles, and clue timestamps. The BP_MindRead_Thoughts_Actor contains the audio component and plays the thought sound clip.

When the player activates the mind-reading ability, the BP_MindRead_Thoughts_Actor moves through the world from the NPC to the player and attaches itself to the player character. When the ability ends, it moves back to the NPC. Because the sound is spatialized, it gradually becomes louder as the actor moves closer to the player, creating the illusion that the player is “concentrating” on the thought—more on this in Part 2.

BPC_NPC_Thoughts is a component attached to the NPC. It serves as the NPC-side manager of sorts. BPC_AmbientThoughtsManager is a component that lives on the player character and manages the player-side logic.

PDA_AmbientThoughts

This is a primary data asset that is associated with each BP_NPCTelepathDefinition (it’s my subclassed version of the Narrative Pro NPC definition).

Variables

Modifiable

Hidden

Functions

In this Data asset, I have two functions. Both are fairly simple.

The first initiates some variables and tells the event graph to start working.

The second. Controls the subtitle state and resets the HUD if I need them off.

Event Graph

The event graph is also fairly simple, but there is a bit of a catch. I have to start the clip only after binding the audio component to the playback event, or it can cause problems. Then, if necessary, I handle the subtitles.

BP_MindRead_Thoughts_Actor

This object was created to move between the NPC and the player, and back, during the mind-reading ability to create a seamless audio change while the player is concentrating/unconcentrating.

Variables

Functions

Normalizing the time gives me a clean 0–1 value, so I can use it to control the transition predictably and return when the move is over.

Lerping between the start position and the target character’s head socket.

When I reach the object’s target, I disable tick.

I’m getting the target narrative character, the duration of the move, and saving the actor’s current position before initiating the move by enabling tick.

Event Graph

BPC_NPC_Thoughts

Variables

Functions

This function controls the gradual volume change for the ambient thought audio. Instead of snapping the volume from one value to another, it uses elapsed time and a curve to smoothly fade from the starting volume to the target volume. This lets the mind-reading audio feel more natural when the player starts concentrating or stops concentrating, because the thought doesn’t suddenly appear or disappear.

Here, I’m just creating the thought actor and placing it. When the game loads, I sometimes encounter an issue where the character's head joint doesn’t exist yet, so I’m just using the NPC location for it now. If I ever want to have a special effect on that thought actor, I would need to change that.

I’m not a huge fan of this function. The only thing it does is tell the CurrentThoughtActor to move. It’s one of the problems that I see in this system and one of the things I would like to change.

This is similar to the function above. A Matrioshka function. It’s to get a variable that is inside a thing that is inside another thing.

Same type of Matrioshka function. Except that this time it’s related to integrating telepathy with the Narrative pro Quest system. More on this in Part 3

Macro

This macro changes the volume in controlled steps, using the current volume to determine its position between the minimum and maximum values. It then uses that position to select a change rate between the minimum and maximum increment values, so the volume can rise or fall more smoothly rather than changing by the same fixed amount each time.

Event Graph

The event graph here is a bit bigger. But I’m basically just initializing some variables and binding to events that let me easily control volume changes for all NPCs at once.

BPC_AmbientThoughtsManager

This class is big, and there are a lot of things going on here. I’ll try to divide things into subjects and explain them as best I can.

Variables

Components

Volume

Post Processing

There are 4 post-processing variables that I’ll discuss in part 3.

Mind Reading Ability Setting

Functions

Volume

Post Processing

There are 4 post-processing functions that I’ll discuss in part 3.

Event Graph

None

To do