Emotions

An 8-axis emotional core that changes as you talk.

Most conversational characters have one facial expression: pleasant. IAMX gives every character a living emotional core — a continuously updated model of how it feels, built from eight independent axes. The core listens to the whole conversation, shifts in real time, and then drives what you actually see and hear: the face, the tone of voice, and the body. Compliment the character and its eyes soften and its shoulders relax; insult it and you watch the warmth drain out of its expression while its voice cools. Nothing is scripted — the mood is derived from the dialogue as it happens.

This page explains the eight axes, how the emotional state evolves over time, how to read and steer it from Blueprint, and how to tune the dynamics per character in the panel.

The eight axes

The emotional core is not a single "happy ↔ sad" slider. It tracks eight primary axes simultaneously, each with its own score. Any real emotional state is a blend across all eight — a character can be joyful and a little afraid, or trusting and surprised, at the same time.

Each axis carries a normalized score. Reading one axis tells you a slice of the mood; reading several tells you the whole picture. The pairs are deliberately complementary — joy against sadness, trust against disgust, fear against anger, surprise against anticipation — so the blend can express nuanced, mixed feelings rather than flipping between a handful of fixed presets.

How it behaves

The emotional core is a dynamic system, not a lookup table. Two forces act on it continuously.

It shifts with the conversation

Every turn of dialogue nudges the axes. The character weighs what was said, who said it, and its own personality, then pushes the relevant axes up or down. This happens live, mid-conversation — you do not need to script triggers or hand-author expression changes. The mood is an emergent read of the exchange so far.

It decays over time

Left alone, the state drifts back toward the character's baseline temperament. A spike of surprise fades within moments; a slow build of trust lingers far longer. This decay is what makes the character feel alive between beats — emotions cool naturally instead of freezing on the last thing that happened. The rate of that return is one of the things you tune per character (see below).

  score
   ▲
1.0│           ╭─ anger spikes on the insult
   │          ╱ ╲
   │         ╱   ╲___
   │        ╱        ╲______ decays back toward baseline
   │   ____╱                ╲__________
0.0│──────────────────────────────────────► time
        turn: "you're being rude"    (no new provocation)

Mood drives three channels at once

The current blend is not just a face parameter. It feeds three output channels simultaneously so the character reads as coherent from head to toe.

Control it from Blueprint

The emotional core is fully scriptable. You can read any axis, override the mood for a scene, and react the instant the state changes — all without touching C++. These nodes live under the IAMX | Emotions category on your character component. Full signatures are in the Blueprint API reference.

A typical wiring

1. Set the opening mood — call Set Mood in BeginPlay to give the scene an emotional starting point (e.g. lean into Trust for a friendly greeter).
2. React to changes — bind On Emotion State Changed and read the axes off the event payload instead of polling every frame.
3. Branch on a threshold — inside the event, use Get Emotion Score on Anger or Fear; above a threshold, trigger a de-escalation line, swap a camera, or flag the session.
4. Punch a scripted beat — on a key story line, Force Set Emotion for a guaranteed reaction, then let decay carry it back.
5. Reset between scenes — call Reset Emotion so the next interaction starts clean.

Tuning per character

The emotional core is data-driven, so its dynamics are configured per character in the panel — no rebuild required. A stoic security guard and an excitable shop assistant can share the same eight axes but feel completely different.

• Decay rate — how quickly each axis returns to baseline. Slow decay makes a character that holds a grudge or stays warm; fast decay makes one that shrugs everything off and resets to neutral.
• Reactivity / dynamics — how strongly the conversation moves the axes. Turn it up for an expressive, mercurial personality; turn it down for a calm, hard-to-rattle one.
• Baseline temperament — the resting blend the state decays toward, so a character can idle cheerful, guarded, or reserved by default.

Because these values live in the character config, you can tune the feel of a character, hit save, and see the change on the next interaction — the same config drives the live experience and any Blueprint logic reading the axes.

Where to go next