Material Library and Material Editor tools

WbpMaterials is the UI Foundry material-authoring module. It gives UI and material teams a project-wide Material Library for discovery and governance, plus per-Material Editor panels for everyday graph inspection and cleanup.

The module does not replace Unreal materials. It reads and edits normal UMaterialInterface, UMaterial, and Material Editor data, then stores catalog metadata in sidecar project files so materials still load normally if the plugin is disabled.

Widget Blueprint animations often key material parameters; Anim Tools can audit and remap those animation tracks, while WBP Materials documents the material assets and exposes graph inspection panels. Animation Workbench reviews clip structure and animation coverage. An optional bridge connects its animations to state-machine definitions.

How To Open It

Open the project-wide Material Library from the top-level UI Foundry editor menu.

When a Material Editor is open, use UI Foundry -> Material to open material-specific panels for that editor. Each panel is scoped to the owning Material Editor instance, so working in two Material Editor windows creates independent panel contexts.

Material Library

The Material Library is a production catalog for finding, previewing, documenting, and organizing materials across a project.

It currently supports:

material scans across supported material domains, including User Interface, Surface, Post Process, Deferred Decal, Light Function, and Volume
table and responsive grid card views
search, sorting, domain filters, tag filters, favorites, collections, recently used materials, issue-only filtering, and metadata filters for status, owner, and version
Auto, Docked, and Expanded layout modes
saved view mode, layout, sort, card size, and active sidebar filters
removable active-filter chips, so search/domain/tag/collection/favorite filters can be cleared without resetting the whole view
a right-side selected-material inspector with summary, details, metadata-field, history, and reference tabs
native Unreal material thumbnails in rows, cards, and the inspector
square 1:1 preview wells that fit non-square preview media without stretching
favorite toggles on the preview surface
hover preview tooltips for material thumbnails
repair reporting for catalog storage issues such as stale metadata index entries, orphaned record files, missing custom preview assets, legacy records, and removed schema-field values

The library is meant for broad browsing and review: finding all UI-domain materials, gathering a reusable collection, checking ownership/status, or opening a material with context.

The inspector tabs keep that review work close to the selected material:

Details shows the core catalog fields and current material facts.
Metadata Fields shows project-defined custom fields for the material’s domain.
History shows the per-material metadata file, legacy metadata path, file state, modified timestamp, read-only/source-control state, and related storage context.
References summarizes parameters, named reroutes, material functions, texture usage, and issue groups with Go To actions when a source graph expression is still available.

Catalog Metadata

Each catalog record can store:

display name
description
category
tags
status
owner
version
favorite state
custom fields defined by the project metadata schema

Display Name is optional. When it is empty, the library shows the material asset name. When it is set, artists can give a material a human-readable catalog title without renaming the asset.

Tags use token-style editing. Press Enter to commit a typed tag, use comma-separated text to add several tags, remove a pill to delete one tag, and press Backspace in an empty tag field to remove the previous pill.

Custom Thumbnails

The Material Library can show either the native Unreal material thumbnail or a catalog override.

Use Set Custom Thumbnail to pick supported external preview media from disk. The tool imports it into the configured catalog preview content path, assigns it as the material’s preview override, and saves the imported asset.

Catalog-managed preview assets are one-per-material. Replacing a custom thumbnail reuses the same generated asset name instead of creating numbered duplicates. When a material is renamed or moved, managed preview assets are kept in sync during refresh. Preview assets assigned outside the managed preview root are treated as shared or user-owned assets and are not moved.

The default managed preview path is shaped like:

/Game/UIFoundry/MaterialCatalog/Previews/{MaterialFolderPath}/{MaterialName}/T_{MaterialName}_Preview

Preview labels distinguish native, custom, and media-style overrides where that distinction matters.

Collections

Collections turn search and review work into reusable material sets.

You can:

create a collection from the selected material
create a collection from the currently visible filtered result
filter the library by collection
add the selected material to the active collection
remove the selected material from the active collection
rename, duplicate, delete, and describe collections from the active collection summary

Collection descriptions are preserved when collections are renamed. Legacy collection records stored as simple material arrays are read and rewritten into the newer object form with Materials and Description fields.

Metadata Settings

Metadata Settings controls the catalog schema for each material domain.

It stores project-wide settings in:

Config/UIFoundryMaterialCatalog/Schema.json

Schemas define which metadata fields are available, which fields appear in the selected-material inspector, and which fields appear as compact card or entry data. Built-in core fields are always available, while project-specific fields can be defined per domain.

Supported field types include single-line text, multi-line text, integer, float, boolean, version, select, multi-select, color, asset reference, and URL. Select and multi-select fields use schema-defined options, and the settings UI validates duplicate field ids, invalid field ids, and select fields with no options before save.

This lets a UI material expose fields such as SDF support, theme slot, 9-slice readiness, or animation compatibility without forcing those fields onto unrelated material domains.

Metadata Settings also controls per-domain UI compliance rule overrides. Missing overrides use UI Foundry defaults, but teams can disable a rule or change its severity to Info, Warning, or Error for a specific material domain.

Per-Material Editor Panels

The Material Editor integration is per-editor, not a single global material tool window. Open panels from UI Foundry -> Material inside a Material Editor.

Current panels:

Catalog Metadata: edit display name, description, category, tags, status, owner, version, favorite state, and schema fields for the open material.
Common Nodes: configure node palettes and add selected node types to the material graph.
Node Bindings+: configure node-spawn shortcuts and use a held-key chooser to select among a key’s assigned nodes.
Named Reroutes: list named reroute declarations, inline rename them, edit reroute colors, navigate to declarations, place usages, select child outputs and remove unused declarations where connections can be preserved safely.
Parameters+ (the parameter organizer): list material parameters, rename supported parameter expressions, edit groups and sort priorities, set defaults, duplicate/delete parameters, move parameters between groups, reorder groups, and auto-index sort priority.
Texture Usage: list texture sample/object usage with size, format, sampler type, usage, sRGB state, and UI-risk severity.
Function Dependencies: inspect direct and transitive material-function dependencies and navigate to source expressions where available.
Particle Preview: supply synthetic particle data for testing material behavior.
Custom Node Validator: provide advisory Custom-node checks and limited repairs, including review of empty code, portability risks and unused inputs.
Graph Heuristics: provide advisory graph checks and limited repairs, with source-node navigation where available.
UI Compliance: check UI material rules with pass/warn/fail summaries, configurable severities, and safe fixes where available.

Panel rows that navigate to graph objects resolve weak references at click time, so deleted or renamed graph expressions do not leave stale raw pointers in panel state.

Dedicated editor tools also manage material-function inputs and outputs. These tools complement parameter naming, grouping, defaults and ordering within material graphs.

Custom Node Validator and Graph Heuristics findings do not establish shader compilation success or GPU cost. Use Unreal’s compiler and appropriate profiling tools to validate those separately. Particle Preview supplies synthetic values for material testing; it does not reproduce a particle simulation.

Node palettes and shortcuts

Use Common Nodes to keep reusable node choices close to the graph. Node Bindings+ assigns one or more node types to a shortcut and lets you choose which node that shortcut places by default.

To use the held-key chooser, drag from a connector and press a configured key, or hold a configured key and click empty graph space. Release the key before the hold delay to place its default node; keep holding to open the chooser. Choose a row and release the spawn key to place it. Press Escape or right-click to cancel. A key press alone continues to the graph’s existing keyboard commands.

Assignments and the hold delay are configurable per user and project. Disabling Manage node-spawn keys returns these gestures to Unreal’s native behavior.

UI Compliance Rules

The UI Compliance panel focuses on material settings that commonly matter for UI production. Current checks include skeletal mesh usage flags, Niagara sprite usage, Pixel Depth Offset, and Scene Texture lookups. The panel reads the material domain, applies project compliance settings, and presents each result with its configured severity.

Use the compliance settings when the same rule should mean different things for different material domains. For example, a Scene Texture lookup might be an error for a strict UI material profile but only a warning for a post-process material review.

Parameters+

Parameters+ is the material-side counterpart to Anim Tools’ material-parameter checks. Anim Tools can find stale animated parameter names in Widget Blueprint animation tracks; Parameters+ shows the material’s current parameter names, groups, default values, and sort priorities so the material author can decide whether the graph or the animation track should change.

Relationship To Animation Tools

Use WBP Materials when you need to understand or govern the material asset itself: metadata, preview media, graph nodes, reroutes, parameters, functions, texture usage, or UI compliance.

Use Anim Tools when the problem lives in a Widget Blueprint animation: an animated material parameter name is stale or a supported material-parameter track needs remapping. General FPS conversion and automatic project-wide animation migration are not implemented.

Use Animation Workbench when you are authoring or reviewing which widgets and properties participate in a clip. If that review shows material-related drift or a suspicious parameter track, jump to Anim Tools for repair or WBP Materials for material-asset inspection.

Storage Model

Catalog metadata is stored in project-level sidecar JSON keyed by material path. The material asset itself remains safe if UI Foundry is removed or disabled.

Catalog editing checks read-only and source-control state, offers checkout where supported, and reports locks. Track Config/UIFoundryMaterialCatalog in source control when the team shares metadata, collections and schemas.

The editor caches catalog metadata, legacy metadata, and domain schemas during a session for responsiveness. Saves through the catalog helpers update those caches so selection changes and details edits remain quick without drifting from the sidecar files.

Current Boundaries

The current implementation is already useful for cataloging, previewing, filtering, collection building, and per-material inspection. Some larger production features are intentionally still future work:

animated GIF/video preview playback and scrub controls
bulk metadata edits and schema migration tooling
broader usage tracking across WBPs, levels, material instances, Niagara, and related UI Foundry modules
drag/drop material placement into compatible editors where Unreal exposes a stable target API