Blender MCP

Tool Selection

Use structured MCP tools (get_scene_info, screenshot) for quick inspection.

Use execute_python for anything non-trivial: hierarchy traversal, material extraction, animation baking, bulk operations. It gives full bpy API access and avoids tool schema limitations.

Use headless CLI for GLTF exports — the MCP server times out on export operations.

Health Check (Always First)

1. get_scene_info — verify connection (default port 9876)
2. execute_python with print("ok") — verify Python works
3. screenshot — verify viewport capture works

If MCP is unresponsive, check that the Blender MCP addon is enabled and the socket server is running.

Complete Export Workflow

This is the end-to-end linear narrative. Follow these steps in order. Do not skip steps.

Step 1: Health Check

Confirm MCP is alive before touching anything else:

# In MCP tool call:
get_scene_info
execute_python: print("ok")
screenshot

If any step fails, stop and fix MCP connectivity first. See Known Errors.

Step 2: Inspect Scene

Run the full hierarchy extraction to understand what you're working with:

import bpy, json

def extract_hierarchy(obj, depth=0):
    data = {
        "name": obj.name,
        "type": obj.type,
        "location": list(obj.location),
        "rotation": list(obj.rotation_euler),
        "scale": list(obj.scale),
        "visible": not obj.hide_viewport,
        "children": [],
    }
    if obj.type == 'MESH' and obj.data:
        data["vertices"] = len(obj.data.vertices)
        data["faces"] = len(obj.data.polygons)
        data["materials"] = [slot.material.name for slot in obj.material_slots if slot.material]
    if obj.type == 'LIGHT':
        data["light_type"] = obj.data.type
        data["energy"] = obj.data.energy
        data["color"] = list(obj.data.color)
    for mod in obj.modifiers:
        if mod.type == 'ARRAY':
            data.setdefault("modifiers", []).append({
                "type": "ARRAY",
                "count": mod.count,
                "offset_object": mod.offset_object.name if mod.offset_object else None,
            })
    for child in obj.children:
        data["children"].append(extract_hierarchy(child, depth + 1))
    return data

scene_data = {
    "name": bpy.context.scene.name,
    "fps": bpy.context.scene.render.fps,
    "frame_start": bpy.context.scene.frame_start,
    "frame_end": bpy.context.scene.frame_end,
    "objects": [],
}
for obj in bpy.context.scene.objects:
    if obj.parent is None:
        scene_data["objects"].append(extract_hierarchy(obj))

print(json.dumps(scene_data, indent=2))

Look for:

• Array modifiers (will balloon file size if baked — must replicate at runtime)
• Objects with many vertices (risk of slow export or large GLB)
• Hidden objects you may or may not want to export
• Missing materials (empty material_slots)

Step 3: Verify Materials

Run the material extraction to catch export-lossy setups before committing to an export:

import bpy, json

def extract_materials():
    materials = []
    for mat in bpy.data.materials:
        if not mat.use_nodes:
            continue
        info = {"name": mat.name, "nodes": [], "warnings": []}
        has_principled = False
        for node in mat.node_tree.nodes:
            node_data = {"type": node.type, "name": node.name}
            if node.type == 'BSDF_PRINCIPLED':
                has_principled = True
                for inp in node.inputs:
                    if inp.is_linked:
                        node_data[inp.name] = "linked"
                    elif hasattr(inp, 'default_value'):
                        val = inp.default_value
                        try:
                            node_data[inp.name] = list(val)
                        except TypeError:
                            node_data[inp.name] = float(val)
            if node.type == 'TEX_IMAGE' and node.image:
                node_data["image"] = node.image.filepath
                node_data["size"] = [node.image.size[0], node.image.size[1]]
                if node.image.size[0] > 2048:
                    info["warnings"].append(f"Large texture: {node.image.filepath} ({node.image.size[0]}x{node.image.size[1]})")
            if node.type in ('TEX_NOISE', 'TEX_VORONOI', 'TEX_WAVE', 'TEX_MUSGRAVE'):
                info["warnings"].append(f"Procedural texture node '{node.name}' ({node.