Getting Started

Learn how to integrate the Grid Placement System into your Unreal Engine project.

Prerequisites

Unreal Engine 5.4 or later
Basic knowledge of Blueprints or C++
Understanding of Unreal Engine's component system

Installation

Install the Grid Placement System plugin from fab.com
Enable the plugin in Edit > Plugins, then restart the editor.

If the plugin does not appear in your Content Browser:

Open your Content Browser settings and enable Show Plugin Content:

The system uses these tags to identify placement surfaces. give tags "Floor", "Wall", "Roof" in your mesh

Blueprint Setup

These instructions assume a fresh setup.
You may reuse or duplicate relevant actors or variables from the plugin content.

An initialization setup is already available in the Content Browser at: /GPS_Core/Demo/Character/UEM_CharacterSetup blueprint.

This blueprint is identical to the preview shown below. For a quick setup, simply copy the nodes from UEM_CharacterSetup into your own character.

Inside UEM_CharacterSetup Blueprint

1. Implement the Interface in Your Placeable Objects Actor

Every placeable object must implement the PlaceableObjectInterface:

Configure the required interface functions:

Get Placement Class (Self is the object itself)

Returning Class is optional, if it’s not provided as shown below, the placement will still function.

Get Class Placement Type (PlacementType variable: Floor, Wall, or Roof).

If PlacementType is not returned as shown below, the placement will default to Floor.

2. (Optional) Add Directional Arrow Component (For Oriented Objects)

For objects that need directional placement (chairs, table and etc):

Reference the DirectionalArrow in the remaining interface class:

3. Add Components to Your Player Pawn

Open your Character Blueprint.
Add PlacementSystemComponent and PlacementObjectRegistry components.

4. Initialize the System (Same as in UEM_CharacterSetup above)

Call InitializePlacementSystem from PlacementHelper in BeginPlay.

5. Register Placeable Objects

Placeable objects can be registered in two ways:

By calling RegisterObject (via PlacementHelper), as shown below

And, By using a DataTable that follows the PlaceableObjectDataTable structure and linking it to the PlacementObjectRegistry component.

6. Create the UI

Add the provided (Default) WBP_PlacementObjectsListWidget to your HUD or Character and configure.

If you want to create your own UI, you can create something like this:

Instantiate WBP_MinimalObjectList for each entry in RegisteredObjects and add it to the WBP_MinimalMenu ScrollBox.

This are WBP_MinimalObjectList hierarchy and variable look like

Add OnClick event on ItemButton (in WBP_MinimalObjectList) to call Start Placing from (PlacementHelper)

7. Begin Play

Yeah, play

Input Controls

Once in placement mode, the system provides these controls:

Camera Controls

Input	Action
AWSD	Camera Movement
Scroll Wheel	Zoom In/Out
L/R Mouse Drag	Camera Panning
E and Q	Up/Down Movement

Object Placement

Input	Action
Left Click	Place Object
Right Click	Rotate Object
X/ESC	Cancel Placing/Editing Object
DEL	Delete Object While Selected
Middle Mouse	Select Object for Editing

Special Modes

Input	Action
Hold Shift	Precision Mode
TAB	Toggle Enter/Exit Placement
ALT	Toggle Cursor

Common Issues and Solutions

"Directional arrows not showing"

Cause: Missing UDirectionalArrowComponent or not returned in GetArrowComponent
Solution: Add arrow component and return it in interface function

"Objects can't be placed on surfaces"

Cause: Surfaces missing required tags ("Floor", "Wall", "Roof")
Solution: Add proper tags to placement surface actors (Default tags are "Floor" if not specified)

"Placement system not responding"

Cause: Components not added to player pawn or system not initialized
Solution: Add both required components and call InitializePlacementSystem

Important Notes

Interface Implementation: MANDATORY for all placeable objects - without this, objects will not work
Directional Arrows: Highly recommended for objects with orientation (chairs, and other Floor object)
Surface Tags: Ensure your floor/wall/roof actors have correct tags ("Floor", "Wall", "Roof")
Component Dependencies: Both PlacementSystemComponent and PlacementObjectRegistry are required
Camera Compatibility: System automatically adapts to camera setup by create Spring Arm Component at Runtime. Third Person, First Person are all supported
Initialization Order: Always initialize the system before registering objects
Asset Loading: The system loads required materials and input actions automatically from the plugin content
Grid Display: Grids appear automatically when you enter placement mode
Collision: Objects validate placement against other objects and world geometry
Placement Types: Objects can only be placed on surfaces matching their defined placement type

Introduction Overview