unreal-pcg-automation

unreal-pcg-automation

Skill Version: 2.0.2 Last Updated: 2026-09-08 Dependencies: Unreal Engine 5.8+, UE 5.8 native MCP (HTTP, port 8000) Status: Production-ready

Preflight first (2026-09-08): before the first build step of any approved plan, run the unreal-project-preflight skill (ue_preflight.py --live --features <list> --plan-block) so plugins and project settings this skill depends on are enabled in ONE restart. Mid-task "class not found / plugin not enabled" errors go back to that Step 0, never to a runtime toggle.

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Execution Model: Direct MCP Connection

CRITICAL: This skill assumes Claude Code is connected to a running Unreal Engine instance via native MCP.

What This Means:

• Execute Python directly in Unreal using mcp__ue58-mcp__execute_python_code
• NO script generation - execute immediately
• Check Unreal Output Log for results (see Debugging section)
• Use multi-phased execution for complex graphs (see below)

Multi-Phased Workflow Pattern:

For complex PCG graphs, use 3 separate executions to avoid crashes and timeouts:

# PHASE 1: Create all nodes (separate execution)
graph = unreal.AssetToolsHelpers.get_asset_tools().create_asset(...)
node1, _ = graph.add_node_of_type(unreal.PCGGetLandscapeSettings)
node2, _ = graph.add_node_of_type(unreal.PCGSurfaceSamplerSettings)
# ... create all nodes
print(f"Created {len(graph.nodes)} nodes")

# PHASE 2: Connect all nodes (separate execution)
graph = unreal.load_asset('/Game/PCG/MyGraph')
graph.add_edge(graph.nodes[0], unreal.Name("Out"), graph.nodes[1], unreal.Name("Surface"))
# ... all connections (NO CODE AFTER LAST add_edge!)

# PHASE 3: Configure properties (separate execution)
graph = unreal.load_asset('/Game/PCG/MyGraph')
s1 = graph.nodes[1].get_settings()  # Use .get_settings() for existing graphs
s1.points_per_squared_meter = 0.05
# ... all property configurations
print("Configuration complete")

Why 3 Phases:

• Overwrite popups can interrupt node creation
• add_edge() triggers async validation (Silent Execution)
• Settings access differs between creation vs existing graphs