$npx -y skills add arjun988/blender-skills --skill geometry-nodesBlender Geometry Nodes for procedural modeling, scatter systems, vegetation, buildings, pipes, cables, and reusable node groups. Use for procedural asset generation and instancing pipelines via MCP.
| 1 | # Geometry Nodes |
| 2 | |
| 3 | Reusable procedural systems. Parametric assets. Performance-aware instancing. |
| 4 | |
| 5 | ## When to Use |
| 6 | |
| 7 | - Scatter systems (rocks, vegetation, debris) |
| 8 | - Parametric buildings, roads, pipes, cables |
| 9 | - Procedural variation without unique modeling |
| 10 | - Kit assembly with randomization |
| 11 | - Non-destructive iteration on large scenes |
| 12 | |
| 13 | ## Workflow |
| 14 | |
| 15 | ``` |
| 16 | Define Parameters → Build Node Tree → Create Node Group (GN_) |
| 17 | → Test Variations → Bake/Instance Decision → Export Integration |
| 18 | ``` |
| 19 | |
| 20 | ## Node Group Standards |
| 21 | |
| 22 | - Prefix: `GN_[System]_[Descriptor]` |
| 23 | - Expose only necessary inputs (seed, density, scale range) |
| 24 | - Document input ranges in group name or custom properties |
| 25 | - Version node groups: `GN_Scatter_Rocks_v02` |
| 26 | |
| 27 | ## Core Patterns |
| 28 | |
| 29 | ### Scatter System |
| 30 | ``` |
| 31 | Mesh Surface → Distribute Points on Faces → Instance on Points |
| 32 | → Randomize Rotation (Z) → Randomize Scale → Realize (optional) |
| 33 | ``` |
| 34 | |
| 35 | ### Building Generator |
| 36 | ``` |
| 37 | Floor Count (input) → Repeat Mesh → Stack Instances |
| 38 | → Window Cut Pattern → Material Variation → Output |
| 39 | ``` |
| 40 | |
| 41 | ### Cable/Pipe Routing |
| 42 | ``` |
| 43 | Curve Input → Curve to Mesh (profile) → Subdivide → Set Material |
| 44 | → Multiple curves from single path node |
| 45 | ``` |
| 46 | |
| 47 | ### Rock Formation |
| 48 | ``` |
| 49 | Ico Sphere → Displace (noise) → Decimate → Instance Scatter |
| 50 | ``` |
| 51 | |
| 52 | ## Randomization |
| 53 | |
| 54 | | Parameter | Typical Range | |
| 55 | |-----------|---------------| |
| 56 | | Scale | 0.8–1.2 (uniform or per-axis) | |
| 57 | | Rotation Z | 0–360° | |
| 58 | | Density | 0.1–2.0 per m² | |
| 59 | | Seed | Integer for reproducibility | |
| 60 | |
| 61 | Always expose seed as group input for art direction iteration. |
| 62 | |
| 63 | ## Performance Rules |
| 64 | |
| 65 | | Scenario | Approach | |
| 66 | |----------|----------| |
| 67 | | Game export | Realize instances → decimate → export mesh | |
| 68 | | Background scatter | Keep instanced; limit count | |
| 69 | | Hero procedural | Bake to static mesh for engine | |
| 70 | | Viewport preview | Limit instance count attribute | |
| 71 | |
| 72 | ## Reusable Systems Library |
| 73 | |
| 74 | | Group | Purpose | |
| 75 | |-------|---------| |
| 76 | | GN_Scatter_Objects | Generic surface scatter | |
| 77 | | GN_Array_Modular | Linear modular repetition | |
| 78 | | GN_Curve_Pipe | Pipe/cable along curve | |
| 79 | | GN_Wall_Variant | Parametric wall sections | |
| 80 | | GN_Vegetation_Cluster | Tree/bush clustering | |
| 81 | |
| 82 | ## MCP Integration |
| 83 | |
| 84 | 1. Create geometry nodes modifier via MCP |
| 85 | 2. Configure group inputs via MCP |
| 86 | 3. Query instance count and final polycount |
| 87 | 4. Realize geometry for export via MCP |
| 88 | 5. Organize GN objects in dedicated collection |
| 89 | |
| 90 | ## Integration with Export |
| 91 | |
| 92 | Before export: |
| 93 | 1. Apply geometry nodes modifier OR |
| 94 | 2. Realize instances and merge OR |
| 95 | 3. Export as instances if engine supports (Unreal HISM) |
| 96 | |
| 97 | Document which approach per target engine. |
| 98 | |
| 99 | ## Constraints |
| 100 | |
| 101 | ### MUST DO |
| 102 | - Create reusable node groups, not one-off trees |
| 103 | - Expose seed and density as inputs |
| 104 | - Test at min/max parameter extremes |
| 105 | - Realize/bake before game export unless engine supports instances |
| 106 | - Name groups with `GN_` prefix |
| 107 | |
| 108 | ### MUST NOT DO |
| 109 | - Million-instance scatter without LOD/culling plan |
| 110 | - Nested realize operations (performance killer) |
| 111 | - Hardcode values that should be inputs |
| 112 | - Export procedural without polycount validation |
| 113 | - Skip variation testing at boundary values |
| 114 | |
| 115 | ## Reference Guide |
| 116 | |
| 117 | | Topic | Reference | Load When | |
| 118 | |-------|-----------|-----------| |
| 119 | | Scatter recipes | `references/scatter-systems.md` | Environment scatter | |
| 120 | | Building generators | `references/building-generators.md` | Architectural procedural | |