Blender Python
that actually runs.

Every render here is a CI artifact.

These aren't mockups. Each example runs headless on Blender 4.5 LTS and 5.1 in the smoke workflow, asserts its own correctness, and exits non-zero if the API drifted. The render is what the code produced.

swatch-grid Procedural Principled materials — metal and dielectric, the emission pattern, and the cross-version set_specular shim.

turntable A slotted-actions Z-rotation turntable keyed through the cross-version channelbag path (get_channelbag_for_slot).

gn-sdf-remesh A Geometry Nodes SDF remesh (MeshToSDFGrid → GridToMesh at the SDF zero-level), with a Set Material node carrying the material through the remesh.

depsgraph-export The depsgraph lifetime contract — evaluated_get().to_mesh() paired with to_mesh_clear() — measured against an OBJ export of the same object.

wave-displace Bulk vertex IO at real scale — 9,409 vertices displaced into a standing wave with one foreach_get and one foreach_set, no per-vertex access.

driver-wave A driver_namespace function driving sixteen column heights through SCRIPTED drivers — the sine skyline is entirely driver-evaluated.

bmesh-gear A 14-tooth gear built entirely with bmesh — profile ring, face, extrude — with bm.free() in a try/finally, exactly as the ownership contract demands.

shader-node-group One reusable shader group declared via tree.interface.new_socket, instanced in two materials with different Tint values — two spheres, one group, two colors.

temp-override-join Join three unit cubes into a staircase under bpy.context.temp_override — the supported replacement for the removed context.copy() dict-pass form.

gn-instance-grid A generative Geometry Nodes tree — Mesh Grid → Instance on Points → Realize Instances → Set Shade Smooth — attached as a NODES modifier with no Group Input geometry.

shape-key-blend A relative Tall shape key that lifts and flares the top face — authored via shape_key_add / key_blocks / .value — read back from the depsgraph-evaluated mesh.

curve-bevel-arc A beveled Bezier semicircle authored on bpy.types.Curve — splines.new('BEZIER'), bezier_points, bevel_depth, use_fill_caps — so the curve renders as a solid tube without a prior mesh conversion.

Workflows the AI loads by name.

Each skill is the canonical pattern for one job — operators, panels, bmesh, geometry nodes, slotted actions — plus the mistakes AI assistants actually make there. Where 4.5 LTS and 5.1 diverge, both code paths are shown.

Anti-patterns, caught before they ship.

Always-on guardrails for the failure modes that make Blender Python look right and run wrong: ops in loops, leaked bmesh, deprecated context dicts, per-vertex Python loops.

Canonical patterns, five to fifty lines.

Standalone, paste-ready answers to the questions that come up every session: the right way to create and delete objects, read bulk vertex data, bind properties, bridge the 4.x/5.x API boundary.

Plus 2 starter templates: extension-addon-template and headless-batch-script-template — a complete Extensions-Platform add-on and a headless batch job with CI exit codes.

Clone it. Point your AI at it.

1. Clone the repo: git clone https://github.com/TMHSDigital/Blender-Developer-Tools
2. Cursor: copy rules/ into your project's .cursor/rules/ — they auto-apply via scope globs; reference skills by name in chat
3. Claude Code: copy skills/ and rules/ into your project workspace, or point Claude Code at the checkout
4. Grab snippets/ and templates/ as starting points for add-ons and headless batch jobs