How to Run Maya in Batch Mode

Important: Post deprecated

Please refer this blog post for most up-to-date Maya batch mode guide

Import Standalone Module

import maya.standalone
maya.standalone.initialize(name='python')

Sometimes, import error could occur

ImportError: No module named maya.standalone

Solution

• check your python interpreter, it should match the maya python2 version. I changed my project interpreter in my pycharm setting.
• setup system environment variable, like the following
• if error still occurs, please check your maya directory

import sys
import os


MAYA_LOCATION = "C:/Program Files/Autodesk/Maya2018"
PYTHON_LOCATION = MAYA_LOCATION + "/Python/Lib/site-packages"

os.environ["MAYA_LOCATION"] = MAYA_LOCATION
os.environ["PYTHONPATH"] = PYTHON_LOCATION

sys.path.append(MAYA_LOCATION)
sys.path.append(PYTHON_LOCATION)
sys.path.append(MAYA_LOCATION+"/bin")
sys.path.append(MAYA_LOCATION+"/lib")
sys.path.append(MAYA_LOCATION+"/Python")
sys.path.append(MAYA_LOCATION+"/Python/DLLs")
sys.path.append(MAYA_LOCATION+"/Python/Lib")
sys.path.append(MAYA_LOCATION+"/Python/Lib/plat-win")
sys.path.append(MAYA_LOCATION+"/Python/Lib/lib-tk")
print('\n'.join(sys.path))

Add Functions

Let’s add a test function to our standalone script.

def test():
    import maya.cmds as cmds
    # full path to your Maya file to OPEN
    maya_file_to_open = r"C:\Users\Lei\Desktop\test.ma"
    # Open your file
    cmds.file(maya_file_to_open, o=True)
    # full path to your Maya file to IMPORT
    maya_file_to_import = r"C:\Users\Lei\Desktop\import.ma"
    # Import the file. the variable "nodes" will hold the names of all nodes imported, just in case.
    cmds.file(maya_file_to_import, i=True, type="mayaAscii")
    render = r"C:\Users\Lei\Desktop\te.ma"
    cmds.file(rename=render)
    cmds.file(force=True, save=True, options='v=1;p=17', type='mayaBinary')
    print('a')

This test function opens a maya file on my desktop and import a maya file and save out as another file.

Execute from mayapy

Execute from Command Line

• to do so, make sure to add mayapy to your system environment variable.

• in system variable: add C:\Program Files\Autodesk\Maya2018\bin to Path

• open command prompt, and enter mayapy [directory/firstStandalone.py]

Execute using subprocess

you can do it without going to command line, but by executing another .py using subprocess

import subprocess

command = 'mayapy [directory/firstStandalone.py]'
process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)
process.wait()

print(process.returncode)  # this return the message from cmd

Standalone Script with Arguments

Sometimes, we would want to pass arguments to our standalone script

get argument as variable using sys.argv

import sys

file_path = sys.argv[1]
file_name = sys.argv[2]

Example from Toadstorm Nerdblog:

import subprocess


maya_path = 'directory/mayapy.exe'  # mayapy or full path to mayapy.exe
script_path = 'directory/firstStandalone.py'


def add_layer(file_names,layer_name):
    for file_name in file_names:
        command = r'mayapy {} {} {}'.format(
            script_path, file_name, layer_name
        )
        
        process = subprocess.Popen(
            command,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE
        )
        process.wait()
        print(process.returncode)  # this return the message from cmd
        
        
if __name__ == '__main__':
    # define a list of filenames to iterate through
    files = ['file1', 'file2', 'file3']
    render_layer = 'a new render layer'
     
    # run procedure, assuming you've already defined it
    add_layer(files, render_layer)

Reference

Tech-Artist Org - Import maya.standalone problem

Stack Overflow - use external python script to open maya and run another script inside maya

Stack Overflow - How to use an external interpreter for Maya?

Toadstorm Nerdblog - Python in Maya Standalone