Computational-Design-Day-Delft-March-2026

Orchestrates complex AEC workflows spanning multiple technologies (Blender Python, IfcOpenShell, Bonsai), providing decision trees for technology selection, workflow sequencing for multi-step BIM operations, and coordination patterns for tasks like IFC creation to Blender visualization to Bonsai authoring. Activates when Claude handles cross-technology AEC tasks, multi-step BIM pipelines, or needs to choose between Blender/IfcOpenShell/Bonsai approaches.

Orchestrates end-to-end BIM workflows combining IfcOpenShell for IFC manipulation, Bonsai for native BIM authoring in Blender, and Blender for 3D operations. Covers common AEC automation patterns: IFC file creation and enrichment, model validation pipelines, geometry extraction workflows, property set management across tools, and batch processing of building models.

Provides a systematic validation checklist for reviewing Blender Python code, checking for deprecated API usage, context errors, version compatibility issues, threading violations, data reference invalidation, incorrect operator calls, and addon/extension structure compliance. Activates when Claude reviews, validates, audits, or checks Blender Python code quality.

Provides a systematic migration process for updating Blender Python scripts and addons across major versions (3.x to 4.x to 5.x), covering API renames, removed functions, changed parameters, extension system migration, BGL to GPU module conversion, and bone collection migration. Activates when migrating, porting, updating, or upgrading Blender Python code between versions.

Guides Blender Python API usage including bpy module structure, RNA data access, context system, dependency graph, and operator invocation. Activates when writing bpy scripts, creating Blender addons, or accessing Blender data blocks programmatically.

Guides GPU drawing in Blender Python using the gpu module, built-in shaders, batch rendering, gpu.state management, SpaceView3D draw handlers, and offscreen rendering. Covers BGL-to-gpu migration. Activates when drawing custom overlays, creating viewport visualizations, or migrating from deprecated bgl module.

Covers Blender Python runtime behavior including mathutils module (Vector, Matrix, Quaternion, KDTree, BVHTree), threading restrictions, undo/redo invalidation of bpy references, application handlers with @persistent, bpy.app.timers, bpy.msgbus subscriptions, and background mode limitations. Activates when dealing with math operations, handlers, timers, or runtime crashes in Blender scripts.

Provides complete Blender Python API version matrix from 3.x through 5.1 with all breaking changes, migration paths, and version-safe coding patterns. Activates when writing version-compatible scripts, migrating addons between Blender versions, or checking API deprecations.

Diagnoses and resolves Blender Python context errors including RuntimeError from restricted context access, operator poll() failures, wrong context for bpy.ops calls, and modal operator context issues. Covers context override removal in 4.0+, temp_override migration, and context-dependent attribute access patterns across Blender 3.x-5.x.

Diagnoses and resolves Blender Python data access errors including ReferenceError from removed objects, undo-invalidated bpy.data references, stale ID pointers after file operations, and data lifecycle management. Covers safe data access patterns, ID reference caching pitfalls, and proper use of bpy.data collections across all Blender versions.

Diagnoses and resolves Blender Python version compatibility errors including AttributeError from removed APIs, ImportError from deprecated modules (bgl in 5.0), breaking changes in operator signatures, and version-specific API differences. Provides migration patterns from 3.x to 4.x to 5.x with complete deprecation timeline and replacement mappings.

Guides complete Blender addon development workflows including project structure for multi-file addons, testing strategies, extension packaging for extensions.blender.org, CI/CD pipelines, dependency management, and addon distribution. Activates when building production Blender addons, packaging extensions, or setting up addon development environments.

Provides implementation workflows for Blender animation including construction sequence animation for AEC, camera walkthrough automation, solar study animations, phasing visualization, NLA workflow orchestration, and batch keyframe operations. Activates when creating construction animations, camera paths, or time-based visualizations for architecture.

Covers Blender automation workflows including batch rendering, headless processing via blender --background, file format I/O automation (OBJ/FBX/STL/USD/glTF), scene assembly scripts, and command-line pipeline integration. Activates when automating Blender workflows, batch processing files, or building render pipelines.

Provides implementation workflows for Blender mesh operations including creating buildings from vertices, IFC geometry visualization, mesh analysis tools, custom mesh generation for AEC, BMesh algorithms, and performance optimization with foreach_get/set. Activates when generating mesh geometry for architecture, implementing custom mesh tools, or creating parametric building elements.

Provides implementation workflows for Blender node systems including creating Geometry Nodes modifiers from Python, building shader node trees programmatically, custom node groups, and linking node setups for AEC visualization. Activates when building node-based setups for parametric modeling, material generation, or procedural geometry.

Provides implementation patterns for Blender operators including modal operators with timer callbacks, file browser integration, undo/redo support, batch processing operators, progress reporting, and multi-step workflows. Activates when implementing complex Blender operators, modal tools, file dialogs, or batch automation scripts.

Defines Blender addon and extension development patterns including legacy bl_info dict, blender_manifest.toml (4.2+), register/unregister lifecycle, multi-file addon structure, AddonPreferences, class naming conventions, and extension packaging for extensions.blender.org. Activates when creating Blender addons, packaging extensions, or migrating from legacy bl_info to manifest format.

Covers Blender animation API including keyframe insertion, FCurve access, Action data blocks, NLA system, BoneCollection (4.0+), armature bone layers migration, driver expressions, and timeline control. Activates when creating animations programmatically, managing keyframes, working with armatures, or setting up drivers.

Covers Blender data management including collections, library overrides, asset system, linked libraries, BlendDataLibraries, data block creation and removal, fake users, and data transfer between files. Activates when managing Blender collections, linking/appending data, working with library overrides, or using the asset system.

Covers Blender material and shader node API including Principled BSDF input name changes (4.0), material slot assignment, UV mapping, texture node setup, material_slot_add, and node-based material creation. Activates when creating materials programmatically, assigning textures, setting up shaders, or migrating material code between Blender versions.

Covers Blender mesh data access including vertices, edges, faces, loops, BMesh creation and editing, from_pydata, UV layers, vertex colors/attributes, normals, and foreach_get/set for bulk operations. Activates when creating or editing mesh geometry, working with BMesh, or manipulating vertex data programmatically.

Covers Blender modifier stack API including adding/removing modifiers, applying modifiers via operators, evaluated mesh access via depsgraph, Geometry Nodes modifier input identifiers, and common AEC modifiers (Array, Boolean, Solidify). Activates when working with modifiers programmatically, applying modifiers to meshes, or accessing Geometry Nodes inputs.

Explains Blender node tree system including Geometry Nodes, Shader Nodes, Compositor Nodes, NodeTreeInterface API (4.0+), creating and linking nodes programmatically, and node group management. Activates when building node trees via Python, creating Geometry Nodes setups, or managing shader node connections.

Defines Blender operator creation patterns including bpy.types.Operator class, execute/invoke/modal methods, poll() functions, bl_idname naming, bl_options flags, return values, operator properties, and context.temp_override. Activates when creating custom Blender operators, registering tools, or handling operator context issues.

Defines Blender UI panel creation including bpy.types.Panel, draw() method, UILayout API (row/column/box/split), bl_space_type, bl_region_type, bl_category, sub-panels, draw_header, menus, and UIList. Activates when creating custom Blender panels, building addon interfaces, or working with UILayout elements.

Defines all bpy.props types (Bool/Int/Float/String/Enum/Vector/Pointer/Collection), PropertyGroup registration, subtypes, units, update callbacks, dynamic enum items, and getter/setter patterns. Activates when adding custom properties to Blender objects, creating PropertyGroups, or handling property update callbacks.

Covers Blender rendering API including render engine selection (EEVEE/Cycles/Workbench), RenderSettings configuration, output format setup, batch rendering via Python, camera setup, scene.render.*, and EEVEE identifier changes across versions. Activates when configuring render settings, automating renders, setting up cameras, or scripting batch render pipelines.

Provides a systematic validation process for IFC models in Bonsai, checking spatial hierarchy completeness, property set compliance, geometry validity, classification correctness, and IDS (Information Delivery Specification) conformance using ifctester. Activates when validating, auditing, checking, or verifying IFC model quality in Bonsai projects.

Explains Bonsai (formerly BlenderBIM) addon architecture including native IFC workflow, tool.Ifc.get() for IfcOpenShell file access, bpy.ops.bim.* operator namespace, BIM property panels, IFC-backed custom properties, and the relationship between Blender objects and IFC entities. Activates when working with Bonsai addon, developing Bonsai extensions, or scripting BIM workflows in Blender.

Catalogs common Bonsai error patterns including IFC schema violations, spatial hierarchy errors, property set failures, geometry representation issues, operator poll failures, drawing generation errors, and BCF/clash workflow problems. Provides diagnostic decision trees and recovery strategies. Activates when debugging Bonsai errors, troubleshooting BIM workflows, or diagnosing IFC-related failures in Blender.

Guides implementation of BIM Collaboration Format (BCF) workflows in Bonsai including creating BCF topics, adding viewpoints with camera snapshots, managing comments, importing/exporting BCF files (v2.1 and v3.0), and integrating BCF issue tracking with IFC element references. Activates when working with BCF files, BIM issue tracking, clash report management, or collaboration workflows in Bonsai.

Guides implementation of clash detection workflows in Bonsai using IfcClash, including defining clash sets with element groups and filters, running intersection tests, reviewing and resolving clashes, smart grouping of results, and integration with BCF for issue tracking. Activates when performing clash detection, interference checking, collision analysis, or spatial coordination in BIM models.

Implements Bonsai classification workflows including applying classification systems (Uniclass 2015, OmniClass, NL-SfB, CCI), bSDD (buildingSMART Data Dictionary) integration for property lookups, managing IfcClassificationReference assignments, and bulk classification operations. Covers classification library import, element-to-classification mapping, and cross-referencing between classification systems.

Implements Bonsai drawing and documentation workflows including creating 2D drawings from IFC models, managing drawing views (plans, sections, elevations), annotation placement, sheet layout composition, SVG generation and export, and titleblock management. Covers the complete documentation pipeline from model views through annotated drawings to printable sheet output.

Implements Bonsai BIM modeling workflows including placing building elements (walls, slabs, columns, beams), assigning IFC types and predefined types, material layer/profile/constituent assignment, parametric modeling with type libraries, and element copy/array operations. Covers the complete element creation pipeline from type selection through geometric representation to spatial assignment.

Implements Bonsai project management workflows including creating new IFC projects with schema selection (IFC2X3/IFC4/IFC4X3), opening and saving native IFC files, project unit configuration (metric/imperial), georeference setup with coordinate reference systems, and project template management. Covers the complete project lifecycle from creation to delivery.

Implements Bonsai quantity takeoff (QTO) workflows including calculating quantities from IFC element geometry, using QtoCalculator for automated base quantity computation, managing IfcElementQuantity sets (area, length, volume, weight), custom quantity set definitions, and bulk quantity operations across building elements. Covers the complete QTO pipeline from geometry analysis to quantity export.

Provides Bonsai IFC element access syntax including tool.Ifc.get() for file access, element-to-Blender-object mapping, IfcStore element retrieval, relating IFC entities to scene objects, and the Bonsai data bridge between bpy.types.Object and IFC elements. Covers core patterns for reading and navigating IFC data within the Bonsai addon context.

Provides Bonsai geometry creation and editing syntax including IFC representation management, profile extrusion, boolean operations, mesh-to-IFC geometry conversion, and Bonsai-specific geometry tools. Covers IfcExtrudedAreaSolid creation, IfcShapeRepresentation assignment, geometry context setup, and the relationship between Blender mesh data and IFC geometric representations.