SMPL Codec

SMPLCodec is a minimal pure-Python library that provides a standardized way to read and write SMPL(-H/-X) parameters of bodies and animations as .smpl files.

See the SMPL Wiki for a general description of the model, and the SMPL-X project page and GitHub for model data and code for the most commonly used version.

Installation

pip install smplcodec

Usage

A .smpl files is simply an NPZ that follows some conventions. It is flat-structured and only contains numeric (specifically int32 and float32) data for maximum interoperability. The library provides a SMPLCodec dataclass which provides convenience methods for reading, writing, and validating SMPL data.

    from smplcodec import SMPLCodec, SMPLVersion, SMPLGender

    # Read a 601-frame sequence from a file
    a = SMPLCodec.from_file("avatar.smpl")

    # The full_pose helper property contains the sequence data
    assert a.full_pose.shape == (601, 55, 3)            
    
    # You can also load AMASS sequences
    a = SMPLCodec.from_amass_npz("motion.npz")

    # Create a new neutral avatar and write it to file
    b = SMPLCodec(smpl_version=SMPLVersion.SMPLX, gender=SMPLGender.NEUTRAL, shape_parameters=np.zeros(10))
    b.write("neutral.smpl")

License

This library is released under the MIT license.