OVERVIEW VIDEO | DOCUMENTATION

Primer Instance Health Bar renders thousands of screen-space health bars from a single batched Slate widget. Instead of spawning a Widget Component per actor, every bar shares one draw call per material - giving you world-space positioning with UI-level control over size, style, text, opacity, and layout.

Drop the component onto any actor, configure size, offset, and curves in the Details panel, and health bars appear in-game with zero Blueprint wiring to draw it. Fully controllable from Blueprints at runtime.

Inspired by MMO and ARPG health bar systems like World of Warcraft and Diablo IV.

CORE FEATURES

• Batched screen-space rendering: one Slate draw call per material, scales to hundreds of bars

• Generational handle system for O(1) lookup with safe validity checking

• Distance-based opacity and scale curves (inline keys or shared UCurveFloat assets)

• Damage trail effect with configurable duration and easing curve

• Per-bar text entries with independent anchor, alignment, margin, font, and color

• Blueprint-overridable Condition objects for custom opacity and name display logic

• Dot product fading: bars fade when viewed at steep angles

• Line-of-sight checking: one trace per frame across all LOS bars, with smooth fade

• Tick throttling: distant bars skip frames automatically for reduced CPU cost

• Behind-camera culling and global enable/disable

• Convenience component for zero-code setup, or use the subsystem API directly

• Array of Extra Material Slots, +1 Draw Call for any number of bars (i.e, instanced)

How To

1. Drop the PrimerHealthBar component onto your actor (or HealthBarBatchComponent)

2. Setup Data Asset Styling

3. Call SetHealth from your damage system

4. Play!

CONFIGURABLE DATA ASSET STYLE

• Bar Size: Dimensions in screen pixels (default: 80x8)

• Pivot: Anchor point on the bar placed at the projected position (default: 0.5, 1.0)

• Material: Material override per bar (null = project default)

• Insignia Slot Array: Material, Size and Alignment for extra details

• Distance Opacity Curve: X=distance, Y=opacity 0-1

• Distance Scale Curve: X=distance, Y=scale multiplier

• Dot Product Fade: Enable/disable with configurable start and end angles

• Trail Duration: Seconds for the damage trail to catch up to current health

• Trail Curve: Easing curve for trail interpolation (empty = linear)

• Health Percent: Initial health 0-1

• Type Scalar: Material-driven style switching (0=basic, 1=elite, 2=boss, etc.)

• Condition: Blueprint-overridable object for opacity and name logic

• Check LOS: Enable line-of-sight tracing with smooth fade

• Start Enabled: Whether this bar ticks on registration

BLUEPRINT API - Component (UPrimerHealthBarComponent)

• SetHealth - Update health percentage

• GetHealth - Read current health

• SetHandleEnabled / IsHandleEnabled - Enable or disable the bar

• SetOpacity - Override manual opacity

• SetType - Change the type scalar for material switching

• SetTextEntries - Replace all text labels

• SetTextEntryText - Update a single text entry by index

• SetTextEntryVisible - Show/hide text entries (index -1 = all)

• SetConfigAsset- Apply a full new config, keeping the same handle

• GetHandle - Retrieve the generational handle for direct subsystem calls

MULTIPLE TEXT ENTRIES ARRAY

• Text: FText content to display

• Font: FSlateFontInfo with font asset and size (default: Roboto 10)

• Text Color: Per-entry color (default: black)

• Anchor: Position on the bar geometry 0-1 (top-left to bottom-right)

• Alignment: Pivot of the text itself 0-1

• Margin: Pixel offset from the computed anchor position

• Enabled: Toggle visibility per entry at runtime

DELEGATES

• OnHealthBarRegistered(Handle, Owner) - Fires when a bar is registered

• OnHealthBarUnregistered(Handle, Owner) - Fires when a bar is unregistered

• OnHealthBarVisibilityChanged(Handle, Owner, bIsVisible) - Fires when a bar transitions between visible and invisible

• OnVisibilityChanged(bIsVisible) - Component-level visibility event

USE CASES

• MMO/ARPG enemy and NPC health bars at scale

• Boss bars with custom material types and forced tick rates

• Floating name tags with distance-based visibility

• Team or faction indicators using the type scalar and material switching

• Damage feedback via configurable trail easing

• Stealth or fog-of-war systems using LOS checking and condition objects

PRIMERS

Part of the Primer series, this plugin prioritizes clarity, control, and practical workflows.