Unreal Engine 5.7 — PCG (Procedural Content Generation)¶

Last verified: 2026-02-13 Status: Production-Ready (as of UE 5.7) Plugin: PCG (built-in, enable in Plugins)

Overview¶

Procedural Content Generation (PCG) is Unreal's node-based framework for generating procedural content at massive scale. It's designed for populating large open worlds with foliage, rocks, props, buildings, and other environmental detail.

Use PCG for:

Procedural foliage placement (trees, grass, rocks)
Biome-based environment generation
Road/path generation
Building/structure placement
World detail population (props, clutter)

DON'T use PCG for:

Gameplay logic (use Blueprints/C++)
One-off manual placement (use editor tools)

⚠️ Note: PCG was experimental in UE 5.0-5.6, became production-ready in UE 5.7.

Core Concepts¶

1. PCG Graph¶

Node-based graph (similar to Material Editor)
Defines generation rules

2. PCG Component¶

Placed in level, executes PCG Graph
Generates content in defined volume

3. PCG Data¶

Point data (positions, rotations, scales)
Spline data (paths, roads, rivers)
Volume data (density, biome masks)

4. Nodes¶

Samplers: Generate points (Grid, Poisson, Surface)
Filters: Remove points based on rules (Density, Tag, Bounds)
Modifiers: Transform points (Offset, Rotate, Scale)
Spawners: Instantiate meshes/actors at points

Setup¶

1. Enable Plugin¶

Edit > Plugins > PCG > Enabled > Restart

2. Create PCG Volume¶

Place Actors > Volumes > PCG Volume
Scale volume to desired generation area

3. Create PCG Graph¶

Content Browser > PCG > PCG Graph
Open PCG Graph Editor

Basic Workflow¶

Example: Forest Generation¶

1. Create PCG Graph¶

Node Setup:

Input (Volume)
  ↓
Surface Sampler (sample volume surface, points per m²: 0.5)
  ↓
Density Filter (use texture mask or noise)
  ↓
Static Mesh Spawner (tree meshes)
  ↓
Output

2. Assign Graph to Volume¶

Select PCG Volume
Details Panel > PCG Component > Graph = Your PCG Graph
Click "Generate" button

Key Node Types¶

Samplers (Point Generation)¶

Grid Sampler¶

Regular grid of points
Configure:
Grid Size: Distance between points
Offset: Random offset per point

Poisson Disk Sampler¶

Random points with minimum distance
Configure:
Points Per m²: Density
Min Distance: Spacing between points

Surface Sampler¶

Points on mesh surfaces or landscape
Configure:
Points Per m²: Density
Surface Only: Only surface, not volume

Filters (Point Removal)¶

Density Filter¶

Remove points based on density value
Input: Texture or noise
Use for: Biome masks, clearings, paths

Tag Filter¶

Filter points by tag
Use for: Conditional spawning

Bounds Filter¶

Keep only points within bounds
Use for: Limiting generation to specific areas

Modifiers (Point Transformation)¶

Rotate¶

Randomize point rotation
Configure:
Min/Max Rotation: Rotation range per axis

Scale¶

Randomize point scale
Configure:
Min/Max Scale: Scale range

Project to Ground¶

Snap points to landscape surface

Spawners (Mesh/Actor Instantiation)¶

Static Mesh Spawner¶

Spawn static meshes at points
Configure:
Mesh List: Array of meshes (random selection)
Culling Distance: LOD/culling settings

Actor Spawner¶

Spawn Blueprint actors at points
Use for: Gameplay actors, interactive objects

Data Sources¶

Landscape¶

Use landscape as input for sampling
Automatically projects to landscape height

Splines¶

Generate content along splines (roads, rivers, paths)
Example: Trees along path

Textures¶

Use textures as density masks
Paint biomes, clearings, areas

Biome Example (Mixed Forest)¶

Graph Setup¶

Input (Landscape)
  ↓
Surface Sampler (density: 1.0)
  ↓
┌─────────────────┬─────────────────┐
│ Tree Biome      │ Rock Biome      │
│ (density > 0.5) │ (density < 0.5) │
├─────────────────┼─────────────────┤
│ Tree Spawner    │ Rock Spawner    │
└─────────────────┴─────────────────┘
  ↓
Merge
  ↓
Output

Spline-Based Generation (Road with Trees)¶

1. Create PCG Graph¶

Spline Input
  ↓
Spline Sampler (sample along spline)
  ↓
Offset (offset from spline path)
  ↓
Tree Spawner
  ↓
Output

2. Add Spline Component to PCG Volume¶

PCG Volume > Add Component > Spline
Draw spline path
PCG Graph reads spline data

Runtime Generation¶

Trigger Generation from C++¶

#include "PCGComponent.h"

UPCGComponent* PCGComp = /* Get PCG Component */;
PCGComp->Generate(); // Execute PCG graph

Stream Generation (Large Worlds)¶

PCG automatically streams with World Partition
Only generates content in loaded cells

Performance¶

Optimization Tips¶

Use culling distance on spawned meshes (LOD)
Limit density (fewer points = better performance)
Use Hierarchical Instanced Static Meshes (HISM) for repeated meshes
Enable streaming for large worlds

Debug Performance¶

// Console commands:
// pcg.graph.debug 1 - Show PCG debug info
// stat pcg - Show PCG performance stats

Common Patterns¶

Forest with Clearings¶

Surface Sampler
  ↓
Density Filter (noise texture with clearings)
  ↓
Tree Spawner (pine, oak, birch)

Rocks on Steep Slopes¶

Landscape Input
  ↓
Surface Sampler
  ↓
Slope Filter (angle > 30°)
  ↓
Rock Spawner

Props Along Road¶

Spline Input (road spline)
  ↓
Spline Sampler
  ↓
Offset (side of road)
  ↓
Street Light Spawner

Debugging¶

PCG Debug Visualization¶

// Console commands:
// pcg.debug.display 1 - Show points and generation bounds
// pcg.debug.colormode points - Color-code points

Graph Debugging¶

PCG Graph Editor > Debug > Show Debug Points
Visualize points at each node in the graph

Migration from UE 5.6 (Experimental) to 5.7 (Production)¶

API Changes¶

// ❌ OLD (5.6 experimental API):
// Some nodes renamed, API unstable

// ✅ NEW (5.7 production API):
// Stable node types, documented API

Migration: Rebuild PCG graphs using stable 5.7 nodes. Test thoroughly.

Limitations¶

Not for gameplay logic: Use Blueprints/C++ for game rules
Large graphs can be slow: Optimize with filters and density reduction
Runtime generation overhead: Pre-generate when possible

Sources¶

https://docs.unrealengine.com/5.7/en-US/procedural-content-generation-in-unreal-engine/
https://docs.unrealengine.com/5.7/en-US/pcg-quick-start-in-unreal-engine/
UE 5.7 Release Notes (PCG Production-Ready announcement)

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