Blender Threejs Export

Blender Three.js Export

Exports the product from Blender as a GLB and writes a standalone HTML file with a Three.js viewer. The viewer includes orbit controls, studio lighting, auto-rotation, and responsive sizing — ready to drop into any website.

Adapted for claude-3d-harness. The original ran a bundled Node script that opened Blender's add-on socket itself and assembled both the Python it sent and the HTML it wrote from command-line text. The export now goes through the MCP server, and the viewer is a fixed template (assets/viewer.html) with four named placeholders. See docs/security-review.md.

Prerequisites

• Blender MCP connected
• A scene loaded in Blender (e.g. after blender-product-polish)

Parameters

Flow

Step 1: Export the GLB

Export the objects that make up the product, not every mesh in the file. The selection the user had is put back.

import bpy, os

OBJECTS = ["<product object name>", "..."]   # from get_scene_info, or the collection this job built
OUT = "<JOB_DIR>/web/model.glb"

os.makedirs(os.path.dirname(OUT), exist_ok=True)
view_layer = bpy.context.view_layer
was_selected = [o.name for o in bpy.context.selected_objects]
was_active = view_layer.objects.active

bpy.ops.object.select_all(action="DESELECT")
for name in OBJECTS:
    bpy.data.objects[name].select_set(True)

bpy.ops.export_scene.gltf(
    filepath=OUT,
    export_format="GLB",
    use_selection=True,
    export_apply=True,          # modifiers are applied in the export only, not on the source mesh
    export_image_format="AUTO",
    export_materials="EXPORT",
    export_texcoords=True,
    export_normals=True,
)

bpy.ops.object.select_all(action="DESELECT")
for name in was_selected:
    if name in bpy.data.objects:
        bpy.data.objects[name].select_set(True)
view_layer.objects.active = was_active

print(f"Exported GLB: {os.path.getsize(OUT) / (1024 * 1024):.1f} MB")

Step 2: Write the viewer

Read assets/viewer.html (next to this file), replace the four placeholders, and write the result to <output>/<name>.html:

For a single file, {{GLB_FILE}} can instead be data:model/gltf-binary;base64,<the GLB, base64-encoded>. Do this only for small models: the page grows by a third of the GLB's size.

Output

<output>/
  model.glb          # GLB export from Blender
  model.html         # Standalone Three.js viewer (CDN imports, no build step)

Tell the user that the page loads Three.js 0.170.0 from cdn.jsdelivr.net when it is opened, and that a browser will not load the GLB from a file:// page: serve the folder (python -m http.server) or use the single-file form.

Viewer Features

• Orbit controls — click and drag to rotate, scroll to zoom, right-click to pan
• Auto-rotation — slow spin to showcase the product
• Studio lighting — 3-point light setup matching the Blender polish look
• Glossy override — every material is made glossy (roughness 0.05, full clearcoat), to match blender-product-polish. For a matte product, remove the "Apply glossy material overrides" block from the page
• Responsive — fills container, works on mobile
• Zero dependencies — uses Three.js from CDN via import maps, no npm/build needed