Files
2026-05-13 13:02:48 +02:00

98 lines
3.4 KiB
Python

"""Wrapper minimal autour de smplx.SMPLXLayer pour decoder les params
de Multi-HMR (betas + thetas + expression) en vertices 3D."""
from __future__ import annotations
import logging
from pathlib import Path
import numpy as np
LOG = logging.getLogger("smplx_decoder")
def _require_torch():
"""Return the torch module, raising a clear error if not installed."""
try:
import torch
return torch
except ImportError as e:
raise RuntimeError(
"smplx_decoder requires the 'multihmr' extra: "
"uv sync --extra multihmr"
) from e
class SMPLXDecoder:
"""Charge SMPL-X NEUTRAL et expose decode(params) -> (verts, joints)."""
def __init__(self, model_path: str, device: str = "mps") -> None:
torch = _require_torch()
# Demote unsupported devices to CPU (mirrors MultiHMRWorker pattern)
if device == "mps" and not torch.backends.mps.is_available():
device = "cpu"
elif device.startswith("cuda") and not torch.cuda.is_available():
device = "cpu"
self.device = device
import smplx
model_path_p = Path(model_path)
if model_path_p.is_file():
# smplx.SMPLXLayer attend le dossier contenant SMPLX_<GENDER>.<ext>
model_folder = str(model_path_p.parent)
ext = "npz" if model_path_p.suffix == ".npz" else "pkl"
else:
model_folder = str(model_path_p)
ext = "npz"
self.layer = smplx.SMPLXLayer(
model_path=model_folder,
gender="neutral",
num_betas=10,
num_expression_coeffs=10,
ext=ext,
).to(self.device).eval()
LOG.info("SMPL-X loaded from %s (device=%s)", model_folder, self.device)
def decode(
self,
betas: "torch.Tensor",
body_pose: "torch.Tensor",
global_orient: "torch.Tensor",
left_hand_pose: "torch.Tensor",
right_hand_pose: "torch.Tensor",
jaw_pose: "torch.Tensor",
expression: "torch.Tensor",
transl: "torch.Tensor",
) -> tuple[np.ndarray, np.ndarray]:
torch = _require_torch()
with torch.no_grad():
out = self.layer(
betas=betas, body_pose=body_pose, global_orient=global_orient,
left_hand_pose=left_hand_pose, right_hand_pose=right_hand_pose,
jaw_pose=jaw_pose, expression=expression, transl=transl,
return_verts=True,
)
return out.vertices.cpu().numpy(), out.joints.cpu().numpy()
def decode_neutral(self) -> tuple[np.ndarray, np.ndarray]:
"""T-pose neutre. Les poses sont des matrices de rotation : on
utilise l'identite (pas zeros, qui collapserait le mesh)."""
torch = _require_torch()
d = self.device
B = 1
def eye(n: int) -> "torch.Tensor":
return torch.eye(3, device=d).expand(B, n, 3, 3).contiguous()
with torch.no_grad():
out = self.layer(
betas=torch.zeros((B, 10), device=d),
body_pose=eye(21),
global_orient=eye(1),
left_hand_pose=eye(15),
right_hand_pose=eye(15),
jaw_pose=eye(1),
expression=torch.zeros((B, 10), device=d),
transl=torch.zeros((B, 3), device=d),
)
return (out.vertices[0].cpu().numpy(),
out.joints[0].cpu().numpy())