Data loader for AIST dataset

fairmotion/data/aist.py

@@ -0,0 +1,65 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+
+import numpy as np
+import pickle
+import torch
+from human_body_prior.body_model.body_model import BodyModel
+from fairmotion.core import motion as motion_class
+from fairmotion.ops import conversions, motion as motion_ops
+from fairmotion.data import amass
+
+"""
+Structure of pkl file in AIST dataset is as follows.
+- smpl_trans (num_frames, 3):  translation (x, y, z) of root joint
+- smpl_scaling (1,): 
+- smpl_loss (1,)
+- smpl_poses (num_frames, 72)
+    0-2 Root orientation
+    3-65 Body joint orientations
+    66-155 Finger articulations
+"""
+
+def load(file, bm=None, bm_path=None, model_type="smplh"):
+    num_betas = 10
+    if bm is None:
+        # Download the required body model. For SMPL-H download it from
+        # http://mano.is.tue.mpg.de/.
+        assert bm_path is not None, "Please provide SMPL body model path"
+        bm = amass.load_body_model(bm_path, num_betas, model_type)
+
+    skel = amass.create_skeleton_from_amass_bodymodel(
+        bm, None, len(amass.joint_names), amass.joint_names,
+    )
+
+    bdata = pickle.load(open(file, "rb"))
+    fps = 60
+    root_orient = bdata["smpl_poses"][:, :3]  # controls the global root orientation
+    pose_body = bdata["smpl_poses"][:, 3:66]  # controls body joint angles
+    trans = bdata["smpl_trans"][:, :3] / bdata["smpl_scaling"][0] # controls global position
+
+    motion = motion_class.Motion(skel=skel, fps=fps)
+
+    num_joints = skel.num_joints()
+    parents = bm.kintree_table[0].long()[:num_joints]
+
+    for frame in range(pose_body.shape[0]):
+        pose_body_frame = pose_body[frame]
+        root_orient_frame = root_orient[frame]
+        root_trans_frame = trans[frame]
+        pose_data = []
+        for j in range(num_joints):
+            if j == 0:
+                T = conversions.Rp2T(
+                    conversions.A2R(root_orient_frame), root_trans_frame
+                )
+            else:
+                T = conversions.R2T(
+                    conversions.A2R(
+                        pose_body_frame[(j - 1) * 3 : (j - 1) * 3 + 3]
+                    )
+                )
+            pose_data.append(T)
+        motion.add_one_frame(pose_data)
+
+    grounded_motion = motion_ops.fix_height(motion, axis_up="y")
+    return grounded_motion

fairmotion/data/amass.py

@@ -48,6 +48,8 @@
 
 
 def create_skeleton_from_amass_bodymodel(bm, betas, num_joints, joint_names):
+    if betas is None:
+        betas = torch.zeros(1, 10).to("cpu")
     pose_body_zeros = torch.zeros((1, 3 * (num_joints - 1)))
     body = bm(pose_body=pose_body_zeros, betas=betas)
     base_position = body.Jtr.detach().numpy()[0, 0:num_joints]