xc3_model_py 
Python bindings to xc3_model for high level and efficient data access to model files for Xenoblade 1 DE, Xenoblade 2, and Xenoblade 3.
Installation
The package can be installed for Python version 3.9, 3.10, 3.11, or 3.12 using pip on newer versions of Windows, Linux, or MacOS. The prebuilt wheels (.whl files) are included only for situations where pip might not be available such as for plugin development for applications. The wheels are zip archives and can be extracted to obtain the compiled .pyd or .so file.
Installing: pip install xc3_model_py
Updating: pip install xc3_model_py --upgrade
Introduction
Parsing and processing happens in optimized Rust code when calling xc3_model_py.load_map or xc3_model_py.load_model. All characters, models, and maps are converted to the same scene hierarchy representation. This avoids needing to add any special handling for maps vs characters. Pregenerated shader JSON databases are available from xc3_lib.
import xc3_model_py
# Get a list of model roots.
roots = xc3_model_py.load_map("xenoblade3_dump/map/ma59a.wismhd", database_path="xc3.json")
for root in roots:
for group in root.groups:
for models in group.models:
for material in models.materials:
print(material.name)
# The shader contains assignment information when specifying a JSON database.
if material.shader is not None:
# Find the image texture and channel used for the ambient occlusion output.
ao = material.shader.sampler_channel_index(2, 'z')
if ao is not None:
sampler_index, channel_index = ao
image_texture_index = material.textures[sampler_index].image_texture_index
image_texture = root.image_textures[image_texture_index]
print(image_texture.name, 'xyzw'[channel_index])
for model in models.models:
# prints (num_instances, 4, 4)
print(len(model.instances.shape))
# This returns only a single root.
root = xc3_model_py.load_model("xenoblade3_dump/chr/chr/01012013.wimdo", database_path="xc3.json")
for group in root.groups:
for models in group.models:
for model in models.models:
# prints (1, 4, 4)
print(len(model.instances.shape))
# Access vertex and index data for this model.
buffers = group.buffers[model.model_buffers_index]
for buffer in buffers.vertex_buffers:
for attribute in buffer.attributes:
print(attribute.attribute_type, attribute.data.shape)
# Access vertex skinning data for each mesh.
for mesh in model.meshes:
vertex_buffer = buffers.vertex_buffers[mesh.vertex_buffer_index]
if buffers.weights is not None:
# Calculate the index offset based on the weight group for this mesh.
unk_type = models.materials[mesh.material_index].unk_type
start_index = buffers.weights.weights_start_index(mesh.skin_flags, mesh.lod, unk_type)
# Get vertex skinning attributes.
for attribute in vertex_buffer.attributes:
if attribute.attribute_type == xc3_model_py.AttributeType.WeightIndex:
# Find the actual per vertex skinning information.
weight_indices = attribute.data + start_index
skin_weights = buffers.weights.skin_weights.weights[weight_indices]
# Note that these indices index into a different bone list than the skeleton.
bone_indices = buffers.weights.skin_weights.bone_indices[weight_indices]
bone_name = buffers.weights.skin_weights.bone_names[bone_indices[0]]
Certain types like matrices and vertex atribute data are stored using numpy.ndarray. This greatly reduces conversion overhead and allows for more optimized Python code. xc3_model_py requires the numpy package to be installed. Blender already provides the numpy package, enabling the use of functions like foreach_get and foreach_set for efficient property access.
# blender
blender_mesh.vertices.add(positions_array.shape[0])
blender_mesh.vertices.foreach_set('co', positions_array.reshape(-1))
Animations can be loaded from a file all at once. The track type is currently opaque, meaning that implementation details are not exposed. The values can be sampled at the desired frame using the appropriate methods.
import xc3_model_py
path = "xenoblade3_dump/chr/ch/ch01027000_event.mot"
animations = xc3_model_py.load_animations(path)
for animation in animations:
print(animation.name, animation.space_mode, animation.play_mode, animation.blend_mode)
print(f'frames: {animation.frame_count}, tracks: {len(animation.tracks)}')
track = animation.tracks[0]
# Each track references a bone in one of three ways.
bone_index = track.bone_index()
bone_hash = track.bone_hash()
bone_name = track.bone_name()
if bone_index is not None:
pass
elif bone_hash is not None:
# Use xc3_model_py.murmur3(bone_name) for hashing the skeleton bones.
pass
elif bone_name is not None:
pass
# Sample the transform for a given track at each frame.
# This essentially "bakes" the keyframes of the animation.
for frame in range(animation.frame_count:)
print(track.sample_scale(frame), track.sample_rotation(frame), track.sample_translation(frame))
print()
xc3_model_py enables Rust log output by default to use with Python's logging module.
Logging can be disabled entirely if not needed using logging.disable().
import logging
# Configure log messages to include more information.
FORMAT = '%(levelname)s %(name)s %(filename)s:%(lineno)d %(message)s'
logging.basicConfig(format=FORMAT, level=logging.INFO)
Documentation
See the pyi stub file for complete function and type information. This also enables autocomplete in supported editors like the Python extension for VSCode. The Python API attempts to match the Rust functions and types in xc3_model as closely as possible.
Installation
The compiled extension module can be imported just like any other Python file. On Windows, rename xc3_model_py.dll to xc3_model_py.pyd. If importing xc3_model_py fails, make sure the import path is specified correctly and the current Python version matches the version used when building. For installing in the current Python environment, install maturin and use maturin develop --release.
Building
Build the project with cargo build --release. This will compile a native python module for the current Python interpreter. For use with Blender, make sure to build for the Python version used by Blender. This can be achieved by activating a virtual environment with the appropriate Python version or setting the Python interpeter using the PYO3_PYTHON environment variable. See the PyO3 guide for details.
Limitations
All data should be treated as immutable. Attempting to set fields will result in an error. Modifying list elements will appear to work, but changes will not be reflected when accessing the elements again. Types from xc3_model_py also cannot be constructed in any way from Python. These limitations may be lifted in the future. Write support may be added in the future as xc3_lib and xc3_model develop.
