MatrixRainRuntime - Matrix Rain DOC

Matrix Rain Runtime Documentation Version 2.0.0

Overview

Matrix Rain Runtime is a code only runtime plugin that creates a configurable digital glyph rain effect. It exposes three Blueprint nodes and three rendering modes, ranging from a full screen overlay to genuine world space text and an optimized layered 3D volume.

Supported Versions and Platforms

Unreal Engine 5.7 Unreal Engine 5.8 Windows development platform Win64 target builds

Installation

Install Matrix Rain Runtime from Fab, enable it under Edit Plugins, and restart the editor if Unreal Engine requests it. No Matrix Rain actor, Blueprint asset, input mapping, or project configuration must be added manually.

Quick Start

1. Open a Level Blueprint, Player Controller, Character, or another runtime Blueprint. 2. Add Event BeginPlay or the gameplay event that should trigger the effect. 3. Add Make Matrix Rain Settings. 4. Set Render Mode to Fast Real 3D World Space. 5. Enable World Space Follows View Target. 6. Connect the settings output to Start Matrix Rain. 7. Connect the execution wire and press Play.

You can also place Start Matrix Rain directly and right click its Settings pin to select Split Struct Pin. Its world context input is normally supplied automatically by Unreal Engine.

Blueprint Nodes

Start Matrix Rain

Starts the effect using the supplied Matrix Rain Settings. The Boolean return value is true when the effect starts successfully. Calling it again updates the active effect instead of stacking a duplicate. Selecting a different render mode replaces the previous mode.

Stop Matrix Rain

Begins the configured fade out and then removes the effect. A Fade Out Seconds value of zero removes it immediately. Repeated stop calls are safe.

Is Matrix Rain Active

Returns true while the effect is running or completing its fade out.

Rendering Modes

Current Screen Overlay

Draws the effect directly over the current game viewport. Use it for menus, HUD effects, hacking sequences, transitions, or full screen presentation. Background Dim affects only this mode.

Real 3D World Space (Text)

Creates actual Text Render components inside the level. It offers genuine 3D placement and camera facing glyphs but is the most expensive mode. Use it for smaller volumes, close shots, or situations where physical world space text is specifically required.

Fast Real 3D World Space

Creates a layered volume using a limited number of world space widget surfaces. It is the default and recommended 3D mode because it provides depth with substantially fewer components. Fast World Layer Count and Fast World Target FPS apply only to this mode.

Settings Reference

Render Mode: selects the active rendering path. Quantity: controls rain density. Valid runtime range: 0.25 to 4.0. Fade In Seconds: start fade duration from 0 to 10 seconds. Fade Out Seconds: stop fade duration from 0 to 10 seconds. Glyph Size: overlay glyph size. Min Trail Length / Max Trail Length: randomized trail length range. Min Fall Speed / Max Fall Speed: randomized falling speed range. Background Dim: overlay only screen darkening. Opacity: glyph intensity percentage. Values above 100 create a stronger glow. Trail Color: color and alpha of trailing glyphs. Head Color: color and alpha of the leading glyph. Rain Text: optional custom source characters. Leave empty for the built in glyph set. Use Rain Text In Order: cycles custom characters in their written order instead of selecting them randomly. Letter Vertical Spacing: controls distance between glyphs in a trail. World Space Follows View Target: moves a world space volume with the primary local camera or pawn. World Space Extents: size of the world space volume in Unreal units. World Column Spacing: base distance between world space columns. World Glyph Size: text size in Real 3D World Space mode. World Space Offset: offsets the world space volume from its anchor. Fast World Layer Count: number of depth layers in fast 3D mode. Valid range: 1 to 16. Fast World Target FPS: layer redraw frequency. Valid range: 1 to 120 FPS.

Custom Rain Text

Rain Text can contain letters, digits, symbols, and Unicode characters. Whitespace and non printing characters are ignored. Visible Unicode output still depends on whether Unreal Engine's active font contains the requested glyph.

When Use Rain Text In Order is false, the plugin selects randomly from the supplied characters. When enabled, every column advances through the custom characters in sequence and loops at the end.

World Space Positioning

Enable World Space Follows View Target when the volume should remain around the primary local camera or pawn. World Space Offset is applied after that location.

When follow behavior is disabled, the volume remains at its current anchor. On a fresh fixed world start, the base anchor is world origin, so use World Space Offset as the desired world placement.

Recommended Starting Preset

Render Mode: Fast Real 3D World Space Quantity: 1.0 Fade In Seconds: 2.0 Fade Out Seconds: 2.0 Opacity: 500 Letter Vertical Spacing: 1.0 World Space Follows View Target: true World Space Extents: 5000, 5000, 5000 World Space Offset: 0, 0, 0 Fast World Layer Count: 6 Fast World Target FPS: 30

Performance Guidance

Prefer Fast Real 3D World Space for gameplay. Lower Quantity to reduce the number of visible columns. Lower Fast World Layer Count to reduce 3D depth and render target cost. Lower Fast World Target FPS when the effect does not require rapid redraws. Keep Real 3D World Space volumes smaller and increase World Column Spacing when performance is important. The plugin automatically clamps unsafe settings, limits generated columns and layers, bounds render target usage, and prevents long frame stalls from causing unbounded simulation work.

Multiplayer

Matrix Rain is intentionally a local cosmetic effect and does not replicate automatically. Call Start Matrix Rain on every client that should see it.

For one affected player, invoke a Client RPC on that player's Player Controller and call Start Matrix Rain inside the client event. For all players, notify every intended client through your replicated gameplay logic and call the node locally on each one. Calling the node only in GameMode or only on a dedicated server cannot create a visible effect.

There is one active Matrix Rain effect per Game Instance. Split screen players in the same Game Instance share the effect, and world space follow mode uses the primary local player view target.

Level Travel and Viewport Changes

An active effect is restored into the new playable world after map travel. If a stop fade is pending during travel, cleanup still completes. Screen overlay mode also reconnects if the game viewport changes.

Troubleshooting

The Blueprint nodes are missing

Confirm Matrix Rain Runtime is enabled under Edit Plugins, then restart the editor if requested. Search for Start Matrix Rain under the Matrix Rain category.

Start Matrix Rain returns false

The call requires a valid playable world and local visual context. It intentionally returns false on a dedicated server, during world teardown, or when no valid Game Instance world is available.

Nothing appears in world space mode

For the simplest test, enable World Space Follows View Target. If using a fixed volume, set World Space Offset to the location where it should appear.

The result looks flat

Verify that Render Mode is Fast Real 3D World Space or Real 3D World Space (Text). Current Screen Overlay is intentionally screen space.

Custom characters do not appear

Confirm Rain Text contains printable non whitespace characters. If only certain Unicode symbols are absent, the current font may not provide those glyphs.

Custom text is not readable in sequence

Enable Use Rain Text In Order. Leave it disabled for randomized Matrix style glyph selection.

The effect is too bright or too faint

Adjust Opacity and the alpha channels of Trail Color and Head Color. Background Dim affects only overlay mode.

Performance is heavier than expected

Use Fast Real 3D World Space, reduce Quantity and Fast World Layer Count, lower Fast World Target FPS, or reduce World Space Extents.

The effect appears only for one multiplayer participant

The visual is not replicated. Ensure Start Matrix Rain executes locally on every intended client.

Removing the Effect

Call Stop Matrix Rain. The plugin fades out using Fade Out Seconds and then releases the overlay, transient actors, widget layers, and text components it created.