After building three environments using UE5’s PCG Framework, I can say it’s the most powerful procedural toolset Epic has released. But the learning curve is real — the documentation assumes you already know what you’re doing.
This guide covers what you actually need to know to start generating forests, biomes, and full levels procedurally.
Contents
- Quick Answer
- What is PCG?
- Setting Up Your First PCG Graph
- Essential Nodes
- Creating a Forest
- UE5.7 Improvements
- Common Mistakes
- Pro Tips
- FAQ
Quick Answer
- PCG = Procedural Content Generation Framework, built into UE5.2+
- Use case: Automatically place foliage, props, buildings, entire biomes
- Learning time: 2-4 hours for basics, weeks for mastery
- Best for: Open worlds, environmental art, rapid prototyping
Enable the PCG plugin, create a PCG Graph asset, add it to a PCG Component in your level, and start connecting nodes. Changes update in real-time.
What is PCG?
The Procedural Content Generation Framework is a node-based system for generating game content at runtime or in-editor. Instead of manually placing 10,000 trees, you define rules and let PCG do the work.
Key concepts:
- Points — Locations in 3D space where things can spawn
- Density — Probability a point will actually spawn something (0-1)
- Attributes — Custom data attached to points (scale, rotation, type)
- Subgraphs — Reusable PCG logic you can embed in other graphs
PCG graphs flow from left to right: generate points → filter/modify → spawn assets.
Setting Up Your First PCG Graph
Step 1: Enable the plugin
Edit → Plugins → search “Procedural Content Generation Framework” → Enable → Restart
Step 2: Create a PCG Graph
Content Browser → Right-click → Create Advanced Asset → PCG → PCG Graph
Step 3: Add to your level
- Create an empty Actor
- Add a PCG Component
- Assign your PCG Graph to the component
- Set the generation trigger (On Load, Manual, etc.)
Step 4: Generate
Select the actor → Details panel → click “Generate”
Your graph executes and spawns content based on your node setup.
Essential Nodes
These nodes handle 90% of beginner use cases:
Samplers (generate points):
- Surface Sampler — Points on landscape/mesh surfaces
- Volume Sampler — Points filling a 3D volume
- Spline Sampler — Points along a spline path
Filters (remove points):
- Density Filter — Remove based on density threshold
- Bounds Filter — Keep points inside/outside a shape
- Self-Pruning — Remove overlapping points
Modifiers (change points):
- Transform Points — Adjust position, rotation, scale
- Attribute Operation — Math on point attributes
- Copy Points — Duplicate with variations
Spawners (create content):
- Static Mesh Spawner — Place meshes at points
- Actor Spawner — Spawn full actors with logic
Creating a Forest
Here’s a practical workflow for a basic forest:
1. Start with Surface Sampler
Connect to your landscape. Set points per square meter to ~0.5 for trees.
2. Add Density Noise
Use Perlin noise to vary density. This creates natural clustering instead of uniform placement.
3. Filter by Slope
Trees don’t grow on cliffs. Filter out points where slope exceeds 30-40 degrees.
4. Self-Prune
Set minimum distance between trees (3-5m for dense forest, 8-10m for sparse).
5. Randomize Transform
Add rotation variation (0-360° on Z). Add scale variation (0.8-1.2).
6. Spawn Meshes
Connect to Static Mesh Spawner. Assign your tree assets with weighted random selection.
7. Layer for Variety
Duplicate your setup for undergrowth, rocks, and grass with different settings.
UE5.7 Improvements
The latest engine version significantly upgraded PCG:
GPU Execution
PCG can now run on GPU for massive performance gains. Large worlds generate 10-50x faster.
Procedural Vegetation Editor (PVE)
New visual tools for foliage placement rules without touching nodes.
Nanite Foliage
PCG-spawned foliage now supports Nanite. Millions of high-poly plants with minimal performance cost.
Hierarchical Generation
Better support for streaming worlds with level-of-detail PCG.
Common Mistakes
Not using Self-Pruning
Points spawn on top of each other. Always prune to maintain minimum distances.
Ignoring execution order
Nodes execute left-to-right, top-to-bottom. Filter before transform, transform before spawn.
Too many points
Start with fewer points than you think. 10,000 trees in editor = pain. Generate, evaluate, scale up.
Forgetting seeds
Set explicit random seeds for reproducible results. Without them, regeneration = different output.
No LOD planning
PCG doesn’t automatically handle LODs. Use mesh LODs and consider culling distances.
Pro Tips
- Use subgraphs for reusable logic (grass layer, rock scatter, etc.)
- Debug view shows point density as color gradient — use it
- Attribute sets let you pass data between graph sections cleanly
- Templates in UE5.7 let you start from proven setups
- Combine with Landscape grass system for micro-detail
- Test at target scale early — what works on a 100m patch may fail at 10km
- Profile generation time — some node combinations are surprisingly expensive
FAQ
Q: Does PCG work at runtime?
A: Yes, but with caveats. Generation is CPU-intensive. Pre-generate what you can, generate dynamically only when needed.
Q: Can I use PCG with World Partition?
A: Yes. PCG integrates with streaming — content generates/despawns as partition cells load/unload.
Q: PCG vs Foliage Tool?
A: Foliage Tool is manual painting. PCG is rule-based generation. Use both — PCG for bulk, Foliage for hand-tuned areas.
Q: How do I make PCG content editable after generation?
A: Use “Convert to Static Mesh Actors” option. This bakes PCG output into regular actors you can move/delete.
Q: Minimum engine version?
A: PCG shipped in UE5.2. Major improvements in 5.3, 5.5, and 5.7. Use 5.7 if possible.
Summary
PCG transforms environment art from tedious placement to creative rule-making. Start with Surface Sampler → Filter → Transform → Spawn. Build complexity gradually. Use subgraphs for reusability.
The UE5.7 improvements (GPU execution, Nanite foliage, PVE) make this the best time to learn PCG. Go procedural.
