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Version: 1.2.0

Building UMG Widgets with the Agent

The UMG/Widgets toolsets let the agent author Widget Blueprints: create the widget asset, add and nest widgets, lay them out, and set properties — so you can describe a UI and get a working widget back.

What the agent can do​

  • Create Widget Blueprints (UserWidget) at a content path.
  • Add widgets to the tree — panels (Canvas, Vertical/Horizontal Box, Overlay, Size Box), and leaf widgets (Text, Button, Image, Progress Bar, etc.).
  • Nest and lay out widgets by parenting them and setting slot properties (alignment, padding, fill).
  • Set widget properties — text, colors, fonts, brushes, sizes.
  • Compile and save the Widget Blueprint so it can be created at runtime.

These are engine-reflected tools (Verb+Noun: create / add / set). Use describe_toolset on the UMG/Widgets toolset for exact signatures.

Typical workflows​

Build a simple HUD​

"Create a Widget Blueprint /Game/UI/WBP_HUD. Add a vertical box, then a Text labelled Score: 0 and a Progress Bar under it. Compile it."

The agent creates the widget, builds the tree, sets the text, and compiles — ready to add to the viewport from your game code or another Blueprint.

Lay out a menu​

"Add three buttons stacked vertically, each with a centered text label: Play, Options, Quit. Give them 8px padding."

For clean, resolution-friendly UMG, prefer content-driven sizing over manual pixel placement:

  • Use Size To Content / Auto on containers where possible instead of fixed Canvas slots.
  • Enable Auto Wrap Text on text that can overflow.
  • Prefer auto alignment (Fill / Center via box slots) over absolute Canvas offsets, so the layout adapts to different screen sizes.

Ask the agent to "size to content and auto-wrap" and it will favor box/overlay layouts over a hand-placed canvas.

Tips​

  • Choose the right container. Vertical/Horizontal Box for stacks, Overlay for layering, Canvas only when you truly need absolute positioning.
  • Name your widgets. Give buttons/texts meaningful names so later edits ("set the Play button text to Start") are unambiguous.
  • Compile and save. Adding widgets marks the asset dirty; have the agent compile and save before you use the widget.

Example via call_tool​

{ "method": "tools/call", "params": {
    "name": "call_tool",
    "arguments": {
      "tool": "AddWidget",
      "args": {
        "widgetBlueprint": "/Game/UI/WBP_HUD",
        "widgetType": "TextBlock",
        "parent": "RootVerticalBox",
        "name": "ScoreText"
      }
    } } }

Tool/argument names are illustrative — confirm them with describe_toolset for the UMG/Widgets toolset in your editor.