How to Use PCG in Unreal Engine 5 — Complete Procedural Generation Tutorial

If you have ever spent hours hand-placing thousands of rocks, trees, or grass patches across a massive open world, you already know why procedural content generation matters. This UE5 PCG tutorial walks you through everything you need to know about the Procedural Content Generation framework in Unreal Engine 5 — from your very first scatter system to advanced techniques like spline-based placement and exclusion zones.

By the end of this guide you will be able to populate entire landscapes in minutes instead of days, iterate on density and variation with a single click, and avoid the most common pitfalls that trip up newcomers.

What Is PCG and Why Should You Care?

PCG stands for Procedural Content Generation. In Unreal Engine 5, the PCG framework is a node-based system that lets you define rules for placing, filtering, and transforming actors and meshes at scale. Instead of dragging assets into the viewport one by one, you build a graph that describes what should be placed, where it should go, and how it should vary.

The benefits are substantial:

Speed — Scatter tens of thousands of instances across a landscape in seconds.
Iteration — Change a single parameter and regenerate the entire system instantly.
Consistency — Rules guarantee uniform quality across every corner of your map.
Non-destructive workflow — PCG graphs are live; nothing is baked until you decide to.

Whether you are building a dense forest, a rocky desert, or an urban environment with procedurally placed street props, PCG is one of the most powerful tools in the UE5 toolbox.

Prerequisites

Before you start, make sure you have the following:

Unreal Engine 5.2 or later — The PCG framework shipped as an experimental feature in 5.2 and became production-ready in 5.3. If possible, use 5.4+ for the most stable experience.
PCG plugin enabled — Open Edit > Plugins, search for “Procedural Content Generation” (or “PCG”), and make sure it is enabled. Restart the editor if prompted.
Basic Unreal Engine knowledge — You should be comfortable navigating the viewport, creating actors, and working with the Content Browser.
A landscape or static mesh floor — PCG needs a surface to scatter onto. A default Landscape actor works perfectly for learning.

PCG Fundamentals

There are three core concepts you need to understand before building anything.

1. The PCG Volume (PCGVolume)

A PCG Volume defines the region in your level where procedural generation takes place. Think of it as a bounding box: only the area inside the volume is eligible for point generation and mesh spawning.

You create one by placing a PCG Volume actor from the Place Actors panel. Scale it to cover the area you want to populate.

2. The PCG Graph

The PCG Graph is where all the logic lives. It is a visual, node-based editor — similar to Blueprints or Material graphs — where you connect nodes to define a pipeline: generate points, filter them, transform them, and finally spawn meshes or actors.

Every PCG Volume references a PCG Graph asset. You can share the same graph across multiple volumes or create unique graphs for different biomes.

3. The Pipeline Flow

A typical PCG pipeline follows this pattern:

Generate points — Create a set of candidate positions (from a surface, grid, spline, or other source).
Filter and modify — Remove points that overlap, fall on steep slopes, or land inside exclusion zones. Adjust density, add randomness to transforms.
Spawn — Convert surviving points into Static Mesh instances (or full actors).

Understanding this generate-filter-spawn flow is the key to mastering PCG. Every graph you build will follow some variation of it.

Step-by-Step: Creating Your First PCG Scatter System

Let’s build a simple rock scatter that distributes meshes randomly across a landscape. This is the “Hello World” of PCG.

Step 1 — Create a PCG Volume

Open the Place Actors panel (shortcut: Shift + 1 in the viewport).
Search for PCG Volume.
Drag it into your level and scale it so it covers the area of your landscape you want to fill. A good starting size is around 5000 x 5000 x 2000 units.

Step 2 — Create and Assign a PCG Graph

In the Content Browser, right-click and choose Procedural Content Generation > PCG Graph.
Name it something descriptive like PCG_RockScatter.
Select your PCG Volume in the Outliner, then in the Details panel find the Graph property and assign your new PCG_RockScatter asset.

Step 3 — Open the PCG Graph Editor

Double-click the PCG Graph asset to open the graph editor. You will see an empty canvas with an Input node and an Output node already wired together. All of your logic will go between these two.

Step 4 — Add a Surface Sampler

The Surface Sampler generates points on whatever geometry exists inside the volume — typically your landscape.

Right-click the canvas and search for Surface Sampler.
Place it and wire the Input node into the Surface Sampler.
In the Surface Sampler’s details, set Points Per Square Meter to something low for testing — 0.05 is a good start (roughly one point every 20 square meters).

Step 5 — Add a Static Mesh Spawner

The Static Mesh Spawner takes points and places mesh instances at each one.

Right-click and add a Static Mesh Spawner node.
Wire the Surface Sampler’s output into the Spawner.
Wire the Spawner into the Output node.
In the Spawner’s details, click the + button under Meshes and select a rock mesh. If you don’t have one, use any Static Mesh from the Starter Content or Megascans library.

Step 6 — Configure Randomization

A scatter system looks artificial if every instance has identical scale and rotation. Fix that with transform randomization.

Random rotation around Z axis:

Right-click and add a Transform Points node. Place it between the Surface Sampler and the Spawner.
Set Rotation Min to (0, 0, 0) and Rotation Max to (0, 0, 360).

Random scale variation:

In the same Transform Points node (or a second one), set Scale Min to (0.7, 0.7, 0.7) and Scale Max to (1.4, 1.4, 1.4).

This gives each rock a unique orientation and a subtle size difference, which is enough to break the repetitive pattern.

Step 7 — Generate and Iterate

Select your PCG Volume in the viewport.
In the Details panel, click Generate (or enable Generate on Load for automatic regeneration).
Thousands of rocks should appear across your landscape.

If the density is too high, lower the Points Per Square Meter value. If rocks are floating or buried, check that your Surface Sampler is tracing against the correct surface type and that collision is enabled on your landscape.

Congratulations — you now have a working PCG scatter system. From here, the process is always the same: add more nodes to refine placement, swap meshes, and layer multiple graphs for complex biomes.

Advanced PCG Techniques

Once you are comfortable with the basics, these techniques will take your environments to the next level.

Landscape-Aware Scatter with Slope and Altitude Filters

Use the Density Filter and Attribute nodes to read landscape data. For example, you can filter out points on slopes steeper than 30 degrees so that trees only grow on relatively flat ground, or restrict certain vegetation to a specific altitude range.

Density Control with Textures

Feed a texture or landscape layer weight into a Density Remap node. Paint density in your landscape material — white means full density, black means none. This gives you artistic control while keeping the procedural foundation.

Spline-Based Placement

Create a spline actor in your level and reference it in a Spline Sampler node instead of a Surface Sampler. This is perfect for placing fence posts along a path, street lights along a road, or trees lining a river bank. Combine it with a Distance to Spline node to create exclusion buffers on either side.

Exclusion Zones

Add PCG Exclusion Volumes in areas where you do not want procedural content — around buildings, inside caves, or over roads. The PCG framework automatically removes any points that fall inside an exclusion volume, so you can hand-craft key areas while leaving the rest procedural.

Multi-Layer Biomes

Create separate PCG Graphs for grass, bushes, rocks, and trees. Assign each to its own PCG Volume (or use subgraphs within a single graph). Layer them so that large trees suppress grass underneath using density masks. This modular approach keeps each graph simple and debuggable.

LOD and Performance Optimization

PCG spawns Instanced Static Meshes by default, which is highly performant. However, with hundreds of thousands of instances you still need to manage draw calls. Use Hierarchical Instanced Static Meshes (HISM), cull distances, and Nanite-enabled meshes to keep frame rates stable on large maps.

How AI Can Accelerate Your PCG Workflows

Building PCG graphs is powerful but time-consuming. Each node needs to be placed, configured, and wired correctly. When you are iterating on a complex biome with dozens of layers, the manual setup adds up fast.

This is where Ultimate Engine CoPilot fits into the picture. It is an AI-powered plugin for Unreal Engine 5 with over 1,050 tools — including a dedicated PCG toolset with 32 actions built specifically for procedural content generation.

Here is what that means in practice:

Generate entire PCG graphs from a text prompt. Describe the scatter system you want (“sparse desert rocks on slopes under 20 degrees, no placement within 500 units of roads”) and the plugin builds the graph for you — Surface Sampler, slope filter, spline exclusion, mesh spawner, and all.
Auto-configure scatter parameters. Instead of manually tuning density, scale ranges, and rotation for each layer, let the AI suggest and apply values based on the asset type and biome context.
Modify existing graphs conversationally. Select a PCG graph and ask the AI to add a density falloff near water, swap the mesh set for a snow biome, or optimize instance counts for performance.

The PCG toolset is part of a broader library of tool categories covering Blueprints, materials, Niagara, landscape, and more. If you are spending significant time on procedural workflows, it is worth exploring how AI can handle the repetitive configuration so you can focus on creative decisions.

Common PCG Mistakes and How to Avoid Them

Even experienced developers run into these issues when starting with PCG. Save yourself the debugging time.

1. Forgetting to Enable Collision on the Landscape

The Surface Sampler relies on collision traces to find the ground. If your landscape has collision disabled (or uses a simplified collision that does not match the visual surface), points will either fail to generate or float above the ground. Make sure Complex Collision as Simple is enabled on your landscape.

2. Setting Density Too High Too Early

It is tempting to crank up Points Per Square Meter to see a lush forest. But at high densities, each regeneration can take minutes and the editor may become unresponsive. Start with a low density (0.01 to 0.05), get the graph logic right, then increase density as a final step.

3. Not Using Seed Values

PCG uses random seeds to determine placement. If you do not set a fixed seed on your graph, results may change unpredictably between regenerations. Lock your seed once you are happy with a layout so it stays consistent across builds.

4. Ignoring Hierarchical Instanced Static Meshes

If you use regular Static Mesh instances instead of HISM, you lose automatic LOD transitions and occlusion culling benefits. Always verify that your Spawner node is configured to use Hierarchical Instanced Static Mesh components.

5. Overlapping PCG Volumes Without Exclusion Logic

When two PCG Volumes overlap, both will generate content in the shared region, causing double-density and z-fighting. Use exclusion zones or partition your volumes so they do not intersect.

Frequently Asked Questions

What version of Unreal Engine do I need for PCG?

PCG was introduced as an experimental feature in UE 5.2 and became stable in UE 5.3. For the best experience with the fewest bugs, use UE 5.4 or later. Earlier versions of Unreal Engine do not include the PCG framework.

Can I use PCG with Nanite meshes?

Yes. PCG works well with Nanite-enabled meshes and it is actually the recommended approach for large-scale scattering. Nanite handles the LOD and draw call management automatically, which complements PCG’s instanced spawning. Just make sure your meshes have Nanite enabled in their asset settings.

How does PCG performance compare to hand-placed foliage?

PCG uses Instanced Static Mesh or Hierarchical Instanced Static Mesh components under the hood, which is the same technology the Foliage tool uses. Runtime performance is essentially identical. The difference is in workflow: PCG is non-destructive, parameterized, and regenerable, while hand-placed foliage is static. For large maps, PCG is almost always faster to create and easier to maintain.

Conclusion

The PCG framework is one of the most impactful additions to Unreal Engine 5 for anyone building environments at scale. With a solid understanding of the generate-filter-spawn pipeline, surface samplers, and transform randomization, you can populate entire worlds in a fraction of the time it would take by hand.

Start with the simple rock scatter system from this tutorial, then layer in slope filters, density textures, spline-based placement, and exclusion zones as your confidence grows. The modular nature of PCG graphs means you can always add complexity incrementally without starting over.

If you want to accelerate the process further, tools like Ultimate Engine CoPilot can generate and configure PCG graphs from natural language descriptions — but even without AI assistance, the techniques in this guide will transform how you approach level design in UE5.

Happy scattering.