Blender Geometry Nodes Studio

Build Geometry Nodes as readable, reusable systems. Use a direct component when it exposes the whole required result more simply, and use Geometry Nodes when fields, adaptive variation, coordinated source rules, scalable instances, complex curve data, reusable topology, or node state provide a documented benefit. Geometry Nodes do not require an explicit user request when that is the better production system.

Suite Authority

Follow ../blender-production-router/references/production-protocol.md and ../blender-production-router/references/native-component-contract.md. The Router owns route, stage, budgets, rollback, and pauses. This skill owns node graphs, fields, instances, simulation zones, and graph evidence only; it may not restart analysis or reroute the task.

When this skill participates in reversible Blockout, require minimum Production Analysis and semantic source/control objects. Formal systems require passed Production Analysis and an approved Part Graph; source assets must then be formal meshes, curves, or intentional instance sources, not Blockout proxies. If the graph generates a primary or structural surface, record its form level, construction method, section/connection logic, realization policy, component target, bevel policy, and evaluated wireframe evidence in construction_graph.json.

Before editing a graph, read graph-layout-contract.md. Read asset-library-findings.md when the task involves outline generation, vegetation, data-flow visuals, text effects, complex modular effects, or flock-like motion. Also read ../blender-production-router/references/system-choice-contract.md. When the Router marks local_asset_library.requested=true with request_origin=user_explicit or request_origin=router_node_candidate, blender-local-asset-library may inspect a source group but this Skill owns graph selection, integration, field contracts, readable layout, and evaluated output evidence. Never use a library asset as an unexplained black box.

Design

1. State the source geometry, domain, density or spacing, orientation, scale range, seed, exclusions, animation requirement, and performance budget.
2. Split large systems into semantic functional groups. Use a thin assembly group to connect generation, sampling, transformation, instancing, material assignment, and output.
3. Expose only meaningful group inputs. Name them by outcome, attach units and ranges, and keep a stable seed input whenever random variation is visible.
4. Preserve instances through the graph. Realize only for a downstream topology operation, collision, export, or per-element edit that requires real geometry.
5. Store or capture IDs and named attributes before topology-changing nodes. Drive time variation from stable IDs rather than random values that reshuffle every frame.

Graph Layout

Lay graphs left to right in these frames: 00 INPUT, 10 DOMAIN, 20 GENERATE, 30 SAMPLE, 40 VARIATION, 50 INSTANCE, 60 FINISH, 90 OUTPUT.

• Keep the main geometry spine on one row.
• Place scalar/vector field controls in lanes above or below the geometry spine.
• Use direct wires for local dependencies; use named reroute buses only for a shared control crossing a stage boundary.
• Keep Zone input/output pairs aligned. A backward wire is valid only for a zone or an explicitly documented feedback relationship.
• Avoid generic node names, unlabeled group inputs, overlapping nodes, and decorative reroute chains.

Build Rules

• Use Instance on Points, collection instances, and curve-to-mesh while preserving instances.
• Use Store Named Attribute only for data crossing a group or topology boundary; use Capture Attribute for short local flow.
• Use Simulation Zone only for stateful motion. For art-directed movement, prefer curves, goal fields, stable phases, or a hybrid.
• Use an Array, linked object, or curve before Geometry Nodes for simple regular repetition.
• Do not recreate ordinary Mirror, Bevel, Solidify, Array, or shader-noise work inside Geometry Nodes.
• Join Geometry only combines geometry streams. It does not weld boundaries or remove internal faces. Use Merge by Distance, Mesh Boolean, a shared curve/profile construction, or downstream reconstruction when the Part Graph requires D_TOPOLOGY_FUSION.
• Do not use procedural detail density to bypass missing Primary, Structural, or Transition Forms.

Inspect And Validate

Run scripts/inspect_geometry_nodes_asset.py with Blender in background to inspect a reference .blend without editing it:

& "F:\SteamLibrary\steamapps\common\Blender\blender.exe" --background "<asset.blend>" --python "<skill>/scripts/inspect_geometry_nodes_asset.py" -- "<report.json>"

For every delivered graph, verify that public inputs are named, node stages are framed, instances remain unrealized unless justified, random inputs use stable IDs where animation needs it, and the graph is readable at normal zoom. Report the group name, public inputs, source/instance/realized counts, seed behavior, simulation/cache state, and viewport/render budget.

Also compare the evaluated output to its Part Graph: connected-component count, visible intersections, endpoint interfaces, real bevel geometry, front/side/top/hero clay, and wireframe. Two topology rollback strikes invalidate the graph output even when the node graph itself is tidy. Populate the output part's procedural contract with source objects, system status, instance and realized counts, stable-ID policy, realization reason, and viewport vertex budget.