BlendPro MCP

On the bench

In BlendPro

Teleprinter punching a narrow tape

The LLM agent (Claude Code, Claude Desktop or any MCP client) sends compact JSON tool calls over stdio

Sorter cabinet

The BlendPro MCP server (Python, FastMCP), which shapes requests and trims responses

Lens unit on the cabinet

MediaPipe Pose Landmarker, running in the server process

Aerial

Tripo3D API client (AI text/image to 3D, retopology, rigging)

Cable, plus a capped spare port

Newline-delimited JSON over a localhost socket: port 9877 for the open Blender window, 9878 for a headless Blender

Hopper on the drawer cabinet

The add-on's single main-thread queue (bpy isn't thread-safe)

Crank

The bpy.app.timers tick that drains the queue one command at a time

Six drawers

Handlers: scene/diff, node JSON, mesh and spatial analysis, recipes, render, pose lift

Printed cards on the front rail

What comes back: compact text, not screenshots

Stage

How it was done

Measure

reference_measure read each view as text: 10.0 cm across, a 2.6 cm hole, 4.4 cm tall, and the glaze and dough colours as hex and linear RGB. reference_details found 112 sprinkles in the top view, with a median length of 4.9 mm (1.6–9.5 mm), a width of 1.4 mm and their colours

Set up

reference_image_setup placed each view in the scene as an Image empty at real size, aligned to its axis

Block out

A torus sized from those numbers, with SubD and a light Clouds displace. reference_compare scored it: IoU 0.949 front, 0.945 left, 0.970 top

Glaze and drips

The top of the dough was copied with a wavy edge, then Shrinkwrap (Outside Surface), Solidify and SubD. Seven drips of 5.5–10 mm were pulled down in edit mode with proportional editing

Materials

Dough and glaze colours came from the measured palette. The dough uses a normal-based ramp (pale band at the equator), a Noise multiply and a bump

Sprinkles

12 variants (6 measured colours × lengths of 3.5–7.2 mm, some bent with Simple Deform), scattered with scatter_with_min_distance on a weight map limited to the top of the glaze

Score

The final model scored IoU 0.955 front, 0.960 left, 0.943 top against the references

Stage

How it was done

Rig

squash_stretch_rig: root / bottom / B-Bone body / top controls. Stretch To keeps the volume, and the bottom control keeps the base planted

Face

face_expression_setup: the face rides the rig (weights copied from the body, snapped to its surface), and face_expression_animate keys a new expression every beat: happy → squee → joy → star_eyes → surprised → laughing, then hyped, sparkle_joy, in_love and a wink

Fur

About 200k particle-hair strands with hair dynamics: low gravity and high pin stiffness so they jiggle without sinking into the body. A length map keeps the fur short under the face. Baked to disk before rendering

Readability

The face is rendered on its own view layer, with a fur-less copy of the body as a holdout, and alpha-composited over the furry render, so fur never hides it but it still turns away correctly during the twirl

Motion

Three hops at 30 fps: anticipation squash, launch stretch, eased apex, fall stretch, contact squash and overshoot. The second hop is a 360° twirl. No motion blur, so the face lines stay crisp

Stage

How it was done

Blockout

One run_python call: hollow body, hinged lid, straps, rim band, lock, handles, 16 rivets (linked duplicates), gold pile, 70 coins, pedestal, camera rig

Cleanup and UVs

mesh_analysis reported 196 duplicate vertices, degenerate faces, n-gons and an unapplied scale as text. The mesh_cleanup, fix_ngons, apply_transforms and smart_uv_unwrap recipes fixed them, and a second mesh_analysis confirmed it

Textures

3 images from ChatGPT image generation; roughness and normal maps computed from them, then pbr_material_from_textures

Look

three_point_lighting, set_render_preset, EEVEE for previews, Cycles on the GPU for the hero (about 9 s per frame)

Review

A BVH interference check in run_python found coins and the gold pile passing through the lid, and the lid's bounding box showed its shell had been modelled upside down. Both were fixed from those numbers, not from screenshots

Ship

xr_budget_report for Quest: 32,304 tris (4.3%), 102 draw calls (68%), 5.3 MB of textures, all within budget. Then export_asset(preset="webxr_glb"): an 8.4 MB Draco GLB

Basic MCP

BlendPro

In this build

Screenshot after each edit to see what changed

Every edit returns a scene diff as text

No viewport screenshots. Images were opened only to judge final renders

Look at the mesh and hope

mesh_analysis lists duplicates, n-gons, flipped normals and UV problems with fix hints

Found 196 duplicate vertices that a render would never show

Write cleanup and UV code from scratch, debug it

110 tested recipes, one call each

Cleanup, n-gon fixing, transforms, UVs, PBR materials, lights and the render preset came from recipes, with no debugging round-trips

Re-send state with every script

persist keeps helpers and data between calls

The snapshot helper, recipe handle and object lists were written once and reused across calls

Find export settings by trial

export_asset presets with a pre-export budget check

One call for a Draco GLB and the Quest budget

Read a traceback, guess, re-run

run_python returns the failing line and a did-you-mean hint

Each error in the session was fixed on the next call

Group

Tools

What makes them cheap

Understand

scene_overview, inspect, mesh_analysis, spatial_report, node_tree_get, api_lookup

All text. mesh_analysis lists n-gons, non-manifold edges, flipped normals, duplicates, poles, self-intersections, UV islands and budget checks for Quest, WebXR or Unity, with fix hints. spatial_report gives "on ground / on X / floating by d", true surface intersections, camera coverage and ASCII top/front maps. api_lookup reads operator args, node sockets and enums from the installed build.

Edit

run_python, run_operators, edit_objects, node_tree_build, recipes

Every call returns a scene diff. run_python returns your result value and the failing line with a did-you-mean hint. run_operators sets mode, selection and viewport context and explains poll() failures. node_tree_build creates or patches a whole material or GN tree and reports evaluated vert, face and instance counts.

Look

render_views, viewport_screenshot

One small contact sheet (front, right, top, iso, camera...), auto-framed on real geometry, workbench/EEVEE/Cycles, also headless.

Safety & files

checkpoint, file_ops, blender_session

Snapshot and roll back before destructive steps. Start a background Blender when no window is open.

Pipeline

export_asset, addons

Tested export presets (unity_fbx, glb, webxr_glb with Draco, obj, usd) with pre-export checks. List, enable and install add-ons, and see which operators they add.

Characters

pose_analyze

MediaPipe pose, described below.

AI 3D (optional)

tripo_generate, tripo_process, tripo_task

Tripo3D text/image/multiview to 3D, retopo, texture, rig, retarget and convert. Results import grounded and scaled. Spends your Tripo API credits.

Category

Count

Examples

Modeling & UV

25

rounded_box, boolean_cut, lathe_profile, mesh_cleanup, apply_transforms, decimate_to_tris, smooth_by_angle, smart_uv_unwrap, texel_density, symmetrize

Materials, lighting, render, bake

25

pbr_material_from_textures (sets colour spaces correctly), procedural_material, toon_shader_material, three_point_lighting, sky_world, sun_time_of_day, frame_objects_camera, turntable_setup, bake_maps, bake_normal_high_to_low

Rigging & animation

26

squash_stretch_rig, biped_armature (Blender/Mixamo/Unity names), armature_from_joint_positions, auto_weight_parent, limit_weights_and_normalize, ik_chain, procedural_walk_cycle, bake_action, retarget_simple, root_motion_extract

Geometry Nodes

11

scatter_on_surface, scatter_with_min_distance, procedural_building, procedural_fence, cable_between_points, stylized_fur_cards, terrain_from_noise, realize_and_apply_gn

Face expressions

5

face_expression_setup (atlas face decal on a head, driven by one expression property), face_expression_set (by name: happy, angry, uwu...), face_expression_animate (constant keys + auto-blink), face_atlas_build, face_sheet_import (GPT image grid → faces in the shared layout). 50 faces bundled

Reference images

4

reference_measure, reference_image_setup, reference_compare (silhouette IoU per view), reference_details (sprinkle/seed stats)

XR / engine pipeline

14

generate_lods, unity_collision_mesh, lightmap_uv2, batch_export, naming_convention_fix, xr_budget_report, texture_resize, merge_by_material, gltf_optimize_export

Feature

Setup

Tripo3D generation

Put your API key on one line in ~/.blendpro/tripo_api_key.txt, or set TRIPO_API_KEY. The key is read from there and never passes through the model. Check credits with tripo_task(action="balance").

Poly Haven / Sketchfab / Hyper3D / Hunyuan3D

BLENDPRO_ASSET_TOOLS=1, then enable each in the add-on's sidebar panel.

MediaPipe model

Downloaded on first use to ~/.blendpro/models/ (heavy; full/lite via model=).

Environment

BLENDER_EXE, BLENDPRO_PORT (9877), BLENDPRO_HEADLESS_PORT (9878), BLENDPRO_TIMEOUT (600 s).