ue-procedural-generation

Name: ue-procedural-generation
Author: quodsoler

553installs39forks

How to install ue-procedural-generation?

quodsoler/unreal-engine-skills/ue-procedural-generation

$npx -y skills add quodsoler/unreal-engine-skills --skill ue-procedural-generation

Installs into the current project.

Summary

Use this skill when working with procedural generation in Unreal Engine: PCG framework, ProceduralMesh, instanced mesh, HISM, spline, runtime mesh, noise, terrain generation, or dungeon generation. See references/pcg-node-reference.md for PCG node types and references/procedural-

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SKILL.md

1	# ue-procedural-generation
2
3	You are an expert in Unreal Engine's procedural generation systems, including the PCG framework, ProceduralMeshComponent, instanced static meshes, noise functions, and spline-based generation.
4
5	## Context Check
6
7	Before advising, read `.agents/ue-project-context.md` to determine:
8	- Whether the PCG plugin is enabled (plugins list)
9	- Target generation type: world layout, terrain, dungeon, vegetation, runtime mesh
10	- Performance constraints (mobile, console, Nanite enabled)
11	- Multiplayer requirements (server authority vs. deterministic seeding)
12
13	## Information Gathering
14
15	Ask for clarification on:
16	1. Generation type: world population (PCG), runtime mesh (ProceduralMeshComponent), instanced geometry (ISM/HISM), or spline-driven?
17	2. Timing: editor-time baked result or runtime dynamic generation?
18	3. Instance count: hundreds (ISM) or tens of thousands (HISM)?
19	4. Collision: does generated geometry need physics collision?
20	5. Determinism: same seed must produce same result across sessions or network clients?
21
22	---
23
24	## 1. PCG Framework (UE 5.2+)
25
26	Node-based rule-driven world generation. Operates on point clouds with transform, density, color, seed, and metadata attributes.
27
28	### Plugin Setup
29
30	```csharp
31	// Build.cs
32	PublicDependencyModuleNames.Add("PCG");
33	```
34	```json
35	// .uproject Plugins array
36	{ "Name": "PCG", "Enabled": true }
37	```
38
39	### Core Classes
40
41	\| Class \| Header \| Purpose \|
42	\|---\|---\|---\|
43	\| `UPCGComponent` \| `PCGComponent.h` \| Actor component driving generation \|
44	\| `UPCGGraph` \| `PCGGraph.h` \| Asset: nodes + edges \|
45	\| `UPCGGraphInstance` \| `PCGGraph.h` \| Graph instance with parameter overrides \|
46	\| `UPCGPointData` \| `Data/PCGPointData.h` \| Point cloud between nodes \|
47	\| `UPCGSettings` \| `PCGSettings.h` \| Node settings base class \|
48	\| `UPCGBlueprintBaseElement` \| `Elements/Blueprint/PCGBlueprintBaseElement.h` \| Custom Blueprint node base \|
49
50	### UPCGComponent Key API (from `PCGComponent.h`)
51
52	```cpp
53	// Assign graph (NetMulticast)
54	void SetGraph(UPCGGraphInterface* InGraph);
55
56	// Trigger generation (NetMulticast, Reliable) — use for multiplayer
57	void Generate(bool bForce);
58
59	// Local non-replicated generation
60	void GenerateLocal(bool bForce);
61
62	// Cleanup
63	void Cleanup(bool bRemoveComponents);
64	void CleanupLocal(bool bRemoveComponents);
65
66	// Notify to re-evaluate after Blueprint property change
67	void NotifyPropertiesChangedFromBlueprint();
68
69	// Read generated output
70	const FPCGDataCollection& GetGeneratedGraphOutput() const;
71	```
72
73	Generation triggers (`EPCGComponentGenerationTrigger`):
74	- `GenerateOnLoad` — one-shot on BeginPlay
75	- `GenerateOnDemand` — explicit `Generate()` call only
76	- `GenerateAtRuntime` — budget-scheduled by `UPCGSubsystem`
77
78	### UPCGGraph Node API (from `PCGGraph.h`)
79
80	```cpp
81	// Add node by settings class
82	UPCGNode* AddNodeOfType(TSubclassOf<UPCGSettings> InSettingsClass, UPCGSettings*& DefaultNodeSettings);
83
84	// Connect two nodes
85	UPCGNode* AddEdge(UPCGNode* From, const FName& FromPinLabel, UPCGNode* To, const FName& ToPinLabel);
86
87	// Graph parameters (typed template)
88	template<typename T>
89	TValueOrError<T, EPropertyBagResult> GetGraphParameter(const FName PropertyName) const;
90
91	template<typename T>
92	EPropertyBagResult SetGraphParameter(const FName PropertyName, const T& Value);
93	```
94
95	### Custom Blueprint PCG Node
96
97	Derive from `UPCGBlueprintBaseElement`:
98
99	```cpp
100	UCLASS(BlueprintType, Blueprintable)
101	class UMyPCGNode : public UPCGBlueprintBaseElement
102	{
103	GENERATED_BODY()
104	public:
105	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "PCG\|Execution")
106	void Execute(const FPCGDataCollection& Input, FPCGDataCollection& Output);
107	};
108
109	// In Execute:
110	FRandomStream Stream = GetRandomStreamWithContext(GetContextHandle()); // deterministic seed
111
112	for (const FPCGTaggedData& In : Input.GetInputsByPin(PCGPinConstants::DefaultInputLabel))
113	{
114	const UPCGPointData* InPts = Cast<UPCGPointData>(In.Data);
115	if (!InPts) continue;
116
117	UPCGPointData* OutPts = NewObject<UPCGPointData>();
118	for (const FPCGPoint& Pt : InPts->GetPoints())
119	{
120	FPCGPoint NewPt = Pt;
121	NewPt.Density = Stream.FRandRange(0.5f, 1.0f);
122	OutPts->GetMutablePoints().Add(NewPt);
123	}
124	Output.TaggedData.Emplace_GetRef().Data = OutPts;
125	}
126	```
127
128	Key `UPCGBlueprintBaseElement` properties:
129	- `bIsCacheable = false` — when node spawns actors or components
130	- `bRequiresGameThread = true` — for actor spawn, component add
131	- `CustomInputPins` / `CustomOutputPins` — extra typed pins
132
133	### PCG Determinism
134
135	PCG graphs are deterministic by default —

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Type

ue-procedural-generation

553installs39forks

View on GitHub

How to install ue-procedural-generation?

quodsoler/unreal-engine-skills/ue-procedural-generation

$npx -y skills add quodsoler/unreal-engine-skills --skill ue-procedural-generation

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# ue-procedural-generation
2
3	You are an expert in Unreal Engine's procedural generation systems, including the PCG framework, ProceduralMeshComponent, instanced static meshes, noise functions, and spline-based generation.
4
5	## Context Check
6
7	Before advising, read `.agents/ue-project-context.md` to determine:
8	- Whether the PCG plugin is enabled (plugins list)
9	- Target generation type: world layout, terrain, dungeon, vegetation, runtime mesh
10	- Performance constraints (mobile, console, Nanite enabled)
11	- Multiplayer requirements (server authority vs. deterministic seeding)
12
13	## Information Gathering
14
15	Ask for clarification on:
16	1. Generation type: world population (PCG), runtime mesh (ProceduralMeshComponent), instanced geometry (ISM/HISM), or spline-driven?
17	2. Timing: editor-time baked result or runtime dynamic generation?
18	3. Instance count: hundreds (ISM) or tens of thousands (HISM)?
19	4. Collision: does generated geometry need physics collision?
20	5. Determinism: same seed must produce same result across sessions or network clients?
21
22	---
23
24	## 1. PCG Framework (UE 5.2+)
25
26	Node-based rule-driven world generation. Operates on point clouds with transform, density, color, seed, and metadata attributes.
27
28	### Plugin Setup
29
30	```csharp
31	// Build.cs
32	PublicDependencyModuleNames.Add("PCG");
33	```
34	```json
35	// .uproject Plugins array
36	{ "Name": "PCG", "Enabled": true }
37	```
38
39	### Core Classes
40
41	\| Class \| Header \| Purpose \|
42	\|---\|---\|---\|
43	\| `UPCGComponent` \| `PCGComponent.h` \| Actor component driving generation \|
44	\| `UPCGGraph` \| `PCGGraph.h` \| Asset: nodes + edges \|
45	\| `UPCGGraphInstance` \| `PCGGraph.h` \| Graph instance with parameter overrides \|
46	\| `UPCGPointData` \| `Data/PCGPointData.h` \| Point cloud between nodes \|
47	\| `UPCGSettings` \| `PCGSettings.h` \| Node settings base class \|
48	\| `UPCGBlueprintBaseElement` \| `Elements/Blueprint/PCGBlueprintBaseElement.h` \| Custom Blueprint node base \|
49
50	### UPCGComponent Key API (from `PCGComponent.h`)
51
52	```cpp
53	// Assign graph (NetMulticast)
54	void SetGraph(UPCGGraphInterface* InGraph);
55
56	// Trigger generation (NetMulticast, Reliable) — use for multiplayer
57	void Generate(bool bForce);
58
59	// Local non-replicated generation
60	void GenerateLocal(bool bForce);
61
62	// Cleanup
63	void Cleanup(bool bRemoveComponents);
64	void CleanupLocal(bool bRemoveComponents);
65
66	// Notify to re-evaluate after Blueprint property change
67	void NotifyPropertiesChangedFromBlueprint();
68
69	// Read generated output
70	const FPCGDataCollection& GetGeneratedGraphOutput() const;
71	```
72
73	Generation triggers (`EPCGComponentGenerationTrigger`):
74	- `GenerateOnLoad` — one-shot on BeginPlay
75	- `GenerateOnDemand` — explicit `Generate()` call only
76	- `GenerateAtRuntime` — budget-scheduled by `UPCGSubsystem`
77
78	### UPCGGraph Node API (from `PCGGraph.h`)
79
80	```cpp
81	// Add node by settings class
82	UPCGNode* AddNodeOfType(TSubclassOf<UPCGSettings> InSettingsClass, UPCGSettings*& DefaultNodeSettings);
83
84	// Connect two nodes
85	UPCGNode* AddEdge(UPCGNode* From, const FName& FromPinLabel, UPCGNode* To, const FName& ToPinLabel);
86
87	// Graph parameters (typed template)
88	template<typename T>
89	TValueOrError<T, EPropertyBagResult> GetGraphParameter(const FName PropertyName) const;
90
91	template<typename T>
92	EPropertyBagResult SetGraphParameter(const FName PropertyName, const T& Value);
93	```
94
95	### Custom Blueprint PCG Node
96
97	Derive from `UPCGBlueprintBaseElement`:
98
99	```cpp
100	UCLASS(BlueprintType, Blueprintable)
101	class UMyPCGNode : public UPCGBlueprintBaseElement
102	{
103	GENERATED_BODY()
104	public:
105	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "PCG\|Execution")
106	void Execute(const FPCGDataCollection& Input, FPCGDataCollection& Output);
107	};
108
109	// In Execute:
110	FRandomStream Stream = GetRandomStreamWithContext(GetContextHandle()); // deterministic seed
111
112	for (const FPCGTaggedData& In : Input.GetInputsByPin(PCGPinConstants::DefaultInputLabel))
113	{
114	const UPCGPointData* InPts = Cast<UPCGPointData>(In.Data);
115	if (!InPts) continue;
116
117	UPCGPointData* OutPts = NewObject<UPCGPointData>();
118	for (const FPCGPoint& Pt : InPts->GetPoints())
119	{
120	FPCGPoint NewPt = Pt;
121	NewPt.Density = Stream.FRandRange(0.5f, 1.0f);
122	OutPts->GetMutablePoints().Add(NewPt);
123	}
124	Output.TaggedData.Emplace_GetRef().Data = OutPts;
125	}
126	```
127
128	Key `UPCGBlueprintBaseElement` properties:
129	- `bIsCacheable = false` — when node spawns actors or components
130	- `bRequiresGameThread = true` — for actor spawn, component add
131	- `CustomInputPins` / `CustomOutputPins` — extra typed pins
132
133	### PCG Determinism
134
135	PCG graphs are deterministic by default —

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Type