ifbars/blender-agent-studio/blender-character-workflow

Blender Character Workflow

Read the shared execution guidance once per task for autonomous decisions, evidence cadence, and long-task continuity.

Match completion to the requested character: a static sculpt needs form and surface evidence; a rigged or animated character also needs deformation evidence. A mesh plus an armature is not a finished rig. Clarify static versus rigged delivery if the request and context leave that consequential choice open.

Establish the character contract

Record intended platform and export format, body/face scope, scale and axis, triangle/material/texture budgets, bone naming and hierarchy requirements, required controls, facial shape keys, poses/actions, and engine/avatar constraints. Record the intended body type and a coherent proportion reference set. Male and female variants need separately reviewed body proportions when requested; a head or clothing swap does not validate another body type. For a requested rig, identify the minimum acceptance poses: neutral, extreme bend for each major joint, reach, twist, locomotion/contact, and any required facial expression.

Review character form and fit

Read character form and fit review for humanoid creation and substantial anatomy/clothing repairs. Establish torso, pelvis, boot and hand proportions against the references before adding detail. Inspect continuous garment/joint surfaces, fitted accessories and skin-texture consistency in neutral and moving poses. These are visual acceptance criteria; passing rig/export metrics alone does not satisfy them.

For realistic, likeness or reference-based briefs, keep the guide's brief-defining feature table. Each row needs an acceptance basis (an opened reference, the brief or an approved design, or unreferenced), a matched model view, the concrete differences and a verdict. A failed download is not a reference. Reopen the reference when you review the feature, and check face construction, hair volume, the named footwear type and native/export pattern parity at delivery scale.

For a requested likeness refinement, follow calibrated proportions and facial likeness. Freeze camera/pose alignment before shape edits, preserve body and tightly framed face snapshots, and check independent views. Keep numerical projection targets separate from identity.

For game characters, resolve silhouette, face identity and fitted garment surfaces before accessory detail. Inspect hands, boots, back and profile at the intended gameplay distance; adding seams to box-like anatomy does not finish it. For a rigged brief, test bend, reach and twist while forms are still editable, then repeat affected poses after clothing/accessory changes. Reserve time for this review and fresh-export deformation rather than spending the whole budget on a neutral hero pose. Static briefs need no invented rig.

Build and rig deliberately

Read connected character construction before creating humanoid hands, footwear or joint surfaces. It describes palm-to-digit construction, footprint/profile shoe lofting, continuous shoulder/pelvis transitions and localized weight bands. Use these construction methods alongside the form review; naming the right parts is not enough.

For a procedural stylized humanoid, the optional Blender-Python starting cages in scripts/build_upper_body.py and scripts/build_hand.py implement these shared boundaries directly. Use them when appropriate instead of rebuilding shoulders from capped tubes or fingers from intersecting primitives. Read the helper contract before importing them. Adapt proportions and inspect the actual result; they are blockouts, not finished anatomy, clothing, or rigs.

Build a complete simple character before finishing regions. Preserve shared boundaries and whole-body landmarks during local refinement. Review hand palm/dorsal/edge views and shoe top/profile views before adding small details. For rigged work, test the simple joint surfaces in bend and reach before clothing detail, then verify the same poses after export. Keep an accepted source checkpoint so a local improvement cannot silently damage the whole.

Preserve requested cartoon proportions and simplified hands. For animated outfits, use the construction guide's rigid/flexible attachment rules: socks and cuffs must follow the local leg surface, soles the feet, and straps their actual supports. Check ankle flexion, foot lift and passing poses from side and rear before replicating an outfit across a character family.

For static character requests, build and review the form without inventing a rigging requirement. The rigging and motion steps below apply when requested.

Retrieve anatomy references with compatible species, age and pose before building a new character or creature. For a low-poly brown bear, for example, look for whole-body front, profile and three-quarter views in a comparable stance, plus head and paw close-ups. Record body/head proportions, muzzle depth, shoulder shape and foot contact from those images. Use separate low-poly examples for plane simplification; do not replace anatomy with a generic animal silhouette or infer all four legs from one occluded photograph.

1. Keep the authored mesh, armature, controls, deformation helpers, and export

mesh in named collections. Apply or deliberately preserve transforms before skinning; document the choice.

1. Create anatomically or mechanically plausible joint placement and semantic

bone names. Separate deform bones from animator controls where the target benefits from it.

1. Keep symmetry and mirror workflows explicit. Limit vertex influences and

normalize weights according to the target runtime requirements.

1. Add IK/FK, constraints, corrective shapes, or drivers only when they solve a

named deformation need. Test without relying on a single flattering pose.

1. For facial work, name shape keys semantically and test combinations that

reveal volume loss, collisions, or eyelid/mouth failures.

Validate export and motion

For locomotion, grounded turns, sitting, carrying and first-person interaction, follow the animation workflow's humanoid motion guide. Declare root-motion ownership, support/grip anchors and reach limits. Separate base motion quality from IK accuracy, inspect weight transfer and transitions at normal speed, and verify grip orientation as well as hand position. Use the real seat, prop and gameplay camera when they are part of the brief. Native constraint success does not establish baked-export or runtime IK behavior.

1. Render the neutral and every contract pose from front, profile, back, and

close-up deformation views. Open the evidence.

1. Check volume preservation, joint collapse, candy-wrapper twisting, clipping,

foot/hand contact, constraint cycles, control readability, and unwanted scale/shear.

1. Export to the requested format, fresh-import it in a clean Blender process,

and compare armature hierarchy, skin weights where supported, materials, actions, frame ranges, scale, and orientation.

1. Use $blender-agent-studio:blender-animation-workflow for action timing and

$blender-agent-studio:blender-asset-validation for authored/exported geometry and hierarchy evidence.

Fit modular VRChat hair

For arbitrary head and hair assets, use scripts/fit_vrchat_hair.py. It fits the largest semantic hair mesh against the upper cranial region in evaluated world space while applying one uniform transform to the complete hair rig. Do not align the full hairstyle minimum Z to the head top; hanging strands and ponytails make that measurement invalid.

Require a 1-8 mm median fitted clearance, no more than 15 mm p95 clearance, fewer than 2% large gaps over 20 mm, and a 1.02-1.10 hair-to-cranium width ratio. Preserve hair armatures, bones, weights, materials, UVs, and separately named style meshes. Treat nearest-normal sign as a warning on multi-component or open head meshes, not proof of penetration; confirm intersections in fixed front, back, side, top, and perspective evidence. A Blender style visibility setup is not proof that Unity/VRChat expression-menu toggles were authored.

Completion gate

Close the loop on each failed region: preserve the current asset and evidence, name the defect, change its construction or binding, regenerate, and reopen the same views and poses. Do not compensate for weak joints with unrequested pads, or hide poor forms with textures. Recheck neighboring surfaces after a regional repair. Stop only when the required checks and visual review agree, or explicitly deliver the remaining defect and evidence as incomplete.

For skinned attachments, use blender_inspect_attachments when available. Bind small, explicit vertex patches on both sides of a seam before posing: sock/shin, cuff/leg, shoe/ankle, strap/support. Use multiple pairs around the boundary; a single centroid can miss rotation. Fix the frame set and permitted gap from the brief/scale before testing. Verify the intended active action/NLA state in the saved inspection copy; the tool samples that state and does not select animation clips. SceneIR object-local points alone do not follow skin deformation. The surface inspector projects evaluated patches into SceneIR and reports the worst frame and per-frame gap. Record selectors in an inspection manifest once topology is stable. Inspection groups are metadata, not additional deform weights; exclude them from bone weight normalization and influence-count audits, or use explicit vertex indices. Repair weights, ownership or geometry, then repeat with unchanged bindings and thresholds. Pass the preserved output as baselineJson on the repair run to detect newly failing frames and changed bindings. Topology changes require rebinding and renewed visual review; never move a marker or widen tolerance just to pass.

This tool requires stable topology and the Rust runtime. If unavailable or unsupported, retain the same pose/close-up review and report the numeric check as unverified. Repeat on the fresh export with explicitly verified export selectors; indices and custom groups may not survive export. A within-tolerance result still requires visual review of intersection, silhouette and deformation.

Resolve or explicitly report the form/fit review findings. Include full-body and feature close-ups from the final revision, with affected poses rechecked after the last geometry/material edit. Report the feature verdicts. Do not claim a realistic or likeness result unless the face and every other brief-defining feature is accepted.

Deliver the editable source, requested export and fresh-import evidence. For a rigged/animated character, include the bone/control map and tested pose/action list. State any target-specific validation that could not be performed in Blender; a successful GLB import is not proof of runtime avatar compatibility.