Custom Python loader plug-in example for Panda3D

test.py

from direct.showbase.ShowBase import ShowBase
from panda3d.core import *

# Use this import to make sure you support the VFS
from direct.stdpy.file import open


class SmurfLoader:
    # Human-readable name of the format
    name = "Smurf"

    # Supported extensions, without leading dot.
    # The primary extension should come first.
    extensions = ['smurf', 'smrf']

    # Set this to True if you use the methods on VirtualFileSystem with
    # auto_unwrap=True to automatically unwrap .gz/.pz files.
    supports_compressed = False

    @staticmethod
    def load_file(path, options, record=None):
        fp = open(path, 'rb')

        # Any raised exception will count as a load failure
        if fp.read(4) != b'smrf':
            raise RuntimeError("Not a valid smurf file!")

        # Mark dependent files as you encounter them (for proper caching)
        if record:
            record.add_dependent_file(referenced_image_path)

        # We may return any PandaNode, but ModelRoot is best
        root = ModelRoot("loaded model")
        return root

    # Optional; but don't define it if you don't support saving
    #@staticmethod
    #def save_file(path, options, node):
    #    open(path).write('stuff')


# To register it explicitly:
registry = LoaderFileTypeRegistry.get_global_ptr()
registry.register_type(SmurfLoader)

# To have Panda import it from an external package, put this in your metadata:
#entry_points={"panda3d.loaders": ["smurf = my_package.my_module:SmurfLoader"]}

# Happy loading!
base = ShowBase()

model = loader.loadModel('model.smurf')
model.reparent_to(base.render)
model.ls()

base.run()