blender-cli

name	blender-cli
description	Use Blender from the command line to render 3D scenes, run Python scripts for batch processing, and convert 3D file formats without the GUI.

Blender CLI

3D creation suite with full command-line interface. Render scenes, batch process, and run Python scripts headlessly.

• Official site: https://www.blender.org
• Docs: https://docs.blender.org/manual/en/latest/advanced/command_line/arguments.html

Common Commands

Rendering

blender -b scene.blend -o /tmp/frame_ -f 1                    # Render frame 1
blender -b scene.blend -o /tmp/frame_ -s 1 -e 250 -a          # Render animation (frames 1-250)
blender -b scene.blend -o /tmp/render.png -f 1 -F PNG          # Render as PNG
blender -b scene.blend -o /tmp/render_ -F OPEN_EXR -a          # Render as OpenEXR

Engine Selection

blender -b scene.blend -E CYCLES -f 1                          # Render with Cycles
blender -b scene.blend -E BLENDER_EEVEE_NEXT -f 1              # Render with EEVEE

Resolution

blender -b scene.blend -o /tmp/out -x 1920 -y 1080 -f 1       # Custom resolution

Python Scripting

blender -b --python script.py                                   # Run Python script
blender -b scene.blend --python script.py                       # Run script on file
blender -b --python-expr "import bpy; print(bpy.data.objects.keys())"  # Inline Python

File Conversion

# Import/export via Python script
blender -b --python-expr "
import bpy
bpy.ops.wm.read_factory_settings(use_empty=True)
bpy.ops.import_scene.fbx(filepath='model.fbx')
bpy.ops.wm.save_as_mainfile(filepath='model.blend')
"

# Export to glTF
blender -b model.blend --python-expr "
import bpy
bpy.ops.export_scene.gltf(filepath='model.glb', export_format='GLB')
"

Scene Info

blender -b scene.blend --python-expr "
import bpy
for obj in bpy.data.objects:
    print(f'{obj.name}: {obj.type}')
"

Agent Best Practices

• Always use -b (background) flag for headless/CLI operation
• Use -o to set output path, -f for single frame, -a for animation
• Use --python or --python-expr for automation and batch processing
• Use -F to set output format: PNG, JPEG, OPEN_EXR, FFMPEG
• CYCLES is higher quality but slower; EEVEE is faster for previews
• Use --python-text to run a text block already in the .blend file
• Check Blender's Python API docs for scripting: https://docs.blender.org/api/current/

Example Workflows

Batch render a scene

blender -b scene.blend -E CYCLES -o /tmp/renders/frame_ -s 1 -e 100 -a

Convert FBX to glTF

blender -b --python-expr "
import bpy
bpy.ops.wm.read_factory_settings(use_empty=True)
bpy.ops.import_scene.fbx(filepath='input.fbx')
bpy.ops.export_scene.gltf(filepath='output.glb', export_format='GLB')
"