blender-motion-state-inspection

Blender Motion State Inspection

When to Use

• A Blender character looks twisted, mirrored, flattened, offset, or foot-sliding in an animation.
• A user asks whether an imported avatar, armature, or retargeted motion matches an expected pose.
• You need to compare rendered evidence with structured facts such as bones, bounding boxes, contacts, and facing vectors.
• A workflow depends on deciding whether a model is a character, prop, proxy mesh, control rig, or broken import.

Core Principle

Do not judge animated 3D assets only from screenshots. Screenshots are review evidence, but they hide axis conventions, bone names, object scale, local transforms, parented meshes, material slots, and frame-by-frame contact state.

First extract structured Blender state, then use viewport screenshots or renders to confirm what the facts imply.

How It Works

1. Establish the clean scene and asset baseline before judging motion.
2. Extract structured facts from Blender using an exporter or Blender Python run inside Blender's own interpreter.
3. Sample the frames most likely to expose contact, orientation, scale, and retargeting errors.
4. Compare the measured facts against the user's expected pose, direction, ground plane, and render goal.
5. Return a concise report that separates confirmed facts, likely causes, and required fixes.

Inspection Workflow

1. Inventory the scene.

   • List meshes, armatures, empties, cameras, lights, modifiers, parent relationships, and hidden objects.
   • Separate character meshes from helper/proxy geometry before judging the avatar.
   • Record object-space and world-space bounding boxes.

2. Identify the skeleton.

   • Capture armature names, pose bones, bone heads/tails, roll, parent chains, constraints, and rest-pose axes.
   • Map semantic bones such as hips, spine, neck, head, shoulders, elbows, hands, thighs, knees, ankles, and feet.
   • Flag missing left/right pairs and unusual naming schemes.

3. Determine forward, up, and side axes.

   • Use the pelvis, spine, shoulders, hips, head, and feet together; do not rely on a single mesh normal.
   • Compare local armature axes with world axes and imported file conventions such as glTF Y-up vs Blender Z-up.
   • Mark likely mirrored or backwards imports when face/head/feet direction conflicts with root motion.