Create a command line to run navipy within blender

bin/blendnavipy.py

+"""
+Run a script within blender
+"""
+import os
+import sys
+import shutil
+import inspect
+import tempfile
+import argparse
+
+
+def activate_virtualenv(venv_path):
+    """ activate venv
+
+    Blender comes with its own python installation. Thus, we need to \
+    tell blender to use our virtualenv where the navigation toolbox \
+    is installed.
+    """
+    if venv_path is None:
+        raise NameError('Python is not running within a virtualenv')
+    filepath = os.path.join(venv_path, 'bin', 'activate_this.py')
+    with open(filepath, 'r') as f:
+        exec(f.read(), dict(__file__=filepath))
+
+
+def blender_version(pyversion):
+    """ check version
+
+    Blender comes with its own version of python, and should be
+    match the one used by navipy
+    """
+    blendpyversion = sys.version_info[:3]
+    if blendpyversion != pyversion:
+        errormsg = 'Blender comes with its own version of python'
+        errormsg += ' (here: {}). To run without hard to debug issues, '
+        errormsg += ' the python version used by navipy (here {}) and '
+        errormsg += 'the python version used by blender should match'
+        errormsg = errormsg.format(blendpyversion, pyversion)
+        raise NameError(errormsg)
+
+
+def parser_blendnavipy():
+    # Create command line options
+    parser = argparse.ArgumentParser()
+    arghelp = 'Path to the environment (.blend) in which your agent lives'
+    parser.add_argument('--blender-world',
+                        type=str,
+                        default=None,
+                        help=arghelp)
+    arghelp = 'Path to your python script to be run in blender'
+    parser.add_argument('--python-script',
+                        type=str,
+                        default=None,
+                        help=arghelp)
+    arghelp = 'Command to run blender\n'
+    arghelp += 'If not provided, the script will try to find the command'
+    arghelp += " by using: shutil.which('blender')"
+    parser.add_argument('--blender-command',
+                        type=str,
+                        default=None,
+                        help=arghelp)
+
+    arghelp = 'To display some stuff \n'
+    arghelp += ' * -v print command \n'
+    arghelp += ' * -vv print also script'
+    parser.add_argument('-v', '--verbose',
+                        action='count',
+                        default=0,
+                        help=arghelp)
+    return parser
+
+
+def main():
+    # Find the name of the virtualenv, so that we can activate
+    # it in blender
+    venv_path = sys.base_prefix
+
+    # Find python version to be checked agains blender python version
+    pyver = sys.version_info[:3]
+
+    # encoding for temporary file
+    encoding = 'utf-8'
+
+    args = parser_blendnavipy().parse_args()
+    if args.blender_command is None:
+        # Find blender command to do a system call
+        args.blender_command = shutil.which('blender')
+
+    python_script = args.python_script
+
+    header = '""" Script generated by {}"""\n'.format(sys.argv[0])
+    with tempfile.NamedTemporaryFile() as tfile:
+        # Start of file
+        tfile.write(header.encode(encoding))
+        tfile.write('# check blender version\n'.encode(encoding))
+        tfile.write('import sys \n'.encode(encoding))
+        for line in inspect.getsourcelines(blender_version)[0]:
+            tfile.write(line.encode(encoding))
+        line = 'blender_version({})\n'.format(pyver)
+        tfile.write(line.encode(encoding))
+        tfile.write('# activate virtualenv within blender\n'.encode(encoding))
+        tfile.write('import os \n'.encode(encoding))
+        for line in inspect.getsourcelines(activate_virtualenv)[0]:
+            tfile.write(line.encode(encoding))
+        line = 'activate_virtualenv(\"{}\")\n'.format(venv_path)
+        tfile.write(line.encode(encoding))
+        tfile.write('# run simulation\n'.encode(encoding))
+        with open(python_script) as infile:
+            for line in infile:
+                tfile.write(line.encode(encoding))
+        tfile.write('print("I am done")\n'.encode(encoding))
+        tfile.seek(0)
+        # End of file
+        if args.verbose > 1:
+            print('Script to be run:')
+            print('=================')
+            print(tfile.read().decode(encoding))
+            tfile.seek(0)
+        command = '{} {} --background --python {}'.format(
+            args.blender_command,
+            args.blender_world,
+            tfile.name)
+        if args.verbose > 0:
+            print('Run blender with the following command')
+            print('======================================')
+            print('>>> ' + command)
+        os.system(command)
+
+
+if __name__ == "__main__":
+    # execute only if run as a script
+    main()