Single Server Rendering

This guide demonstrates how to automate multi-camera rendering from a single .blend file using Blender’s bpy module on Brender Cloud.

Example Files

Download Sample File
Sample Script Code (see below)

Core Script


import bpy
import os
 
def render_cameras():
    # Get output path from environment variable
    output_folder = os.getenv('BC_OUTPUT_FOLDER', '/default/output/path')
    
    # Find all cameras in scene
    cameras = [obj for obj in bpy.data.objects if obj.type == 'CAMERA']
    
    if not cameras:
        print("No cameras found in scene")
        return
    
    scene = bpy.context.scene
    
    for camera in cameras:
        # Set active camera
        scene.camera = camera
        
        # Configure output path
        scene.render.filepath = os.path.join(
            output_folder, 
            f"{camera.name}"
        )
        
        print(f"Rendering {camera.name} => {scene.render.filepath}")
        bpy.ops.render.render(animation=False, write_still=True)
 
if __name__ == "__main__":
    render_cameras()

Key Components Explained

1. Camera Discovery


cameras = [obj for obj in bpy.data.objects if obj.type == 'CAMERA']

Finds all camera objects in the current Blender scene.

2. Output Configuration


scene.render.filepath = os.path.join(output_folder, f"{camera.name}_frame_####")

Uses BC_OUTPUT_FOLDER environment variable to set render destination paths.

⚠️

Use always BC_OUTPUT_FOLDER for proper path handling. Your render output may be lost if you use a hardcoded path.

3. Render Execution


bpy.ops.render.render(animation=False, write_still=True)

Renders single frame for each camera with final quality settings.

Environment Variables

Default Variables

Variable	Description	Example Usage
`BC_OUTPUT_FOLDER`	The output folder for the current server, where rendered frames and other files are saved.	`bpy.context.scene.render.filepath = os.path.join(os.getenv('BC_OUTPUT_FOLDER'), 'frame_####')`
`BC_SERVER_INDEX`	The index of the current server within a server array; useful for distributing tasks.	Set automatically during execution.
`BC_SERVER_ARRAY_SIZE`	Total number of servers in use; this variable is only available when more than one server is active.	Used to coordinate parallel tasks across servers.

Custom Variables

Add custom key-value pairs via the Add Env button in job configuration:

Variable	Description	Example Usage
`MY_CUSTOM_VAR`	Custom environment variable	`os.getenv('MY_CUSTOM_VAR', 'default_value')`

Usage Steps

Upload Script

Navigate to Scripts Dashboard
Upload multi_camera_render.py

Test Script

Click on script name to access detail view
Click Test Script to run a test render
If successful, proceed to job configuration

Configure Job

Navigate to New Render
Upload your .blend file or .zip containing .blend and assets
Select multi_camera_render.py from the script dropdown
Choose 1 server for rendering (for multi-server rendering, see Multi-Server Rendering)

Launch Render

Monitor progress via Render Job Details > Click on job ID cell to view details and logs

Expected Output


# BC_OUTPUT_FOLDER: /app/bc_output/
/app/bc_output/
├── cam_001.png
├── cam_002.png
└── cam_003.png

This script pattern works for 1-10 cameras. For larger quantities (>20 cameras), consider multi-server rendering.

Download Output

Navigate to Render Job Details > Click on job ID cell
Click Download to retrieve rendered frames (.zip)
Zip file contains all frames rendered by the script