Follow A-SDF 的Data Generation部分：
We follow
(1) ANSCH to create URDF for shape2motion dataset
(1-2) URDF2OBJ（本人认为是1-2之间需要进行的重要的过渡部分）
(2) Manifold to create watertight meshes
(3) and modified mesh_to_sdf for generating sampled points and sdf values.

1. ANSCH to create URDF for shape2motion dataset

follow这个github: ANSCH

（1）克隆数据集，编辑自己的路径信息

git clone https://github.com/dragonlong/articulated-pose.git # 克隆仓库
# global_info主要放路径信息，通过下行命令编辑路径信息
vim global_info.py

在global_info.py中，主要修改192行的self.base_path路径，改成克隆下来文件夹的位置，我这里改成/mnt/d/sdc/liutong/codes/articulated-pose。

（2）Shape2Motion数据集的解压和使用

因为这里需要使用到Shape2Motion数据集，所以下载一下，Shape2Motion项目主页：Shape2Motion，Shape2Motion下载链接：Shape2Motion下载链接

下载好Shape2Motion数据集后，在zip文件路径做如下操作

unzip 'Motion Dataset v0.zip' # 解压数据集
mv 'Motion Dataset v0' shape2motion # 重命名数据集
mv shape2motion /mnt/d/sdc/liutong/codes/articulated-pose/dataset/ # 将数据集移动到目标目录下

（3）json2urdf

follow github上的操作：

cd tools # 进入工具文件夹
python json2urdf.py	# 执行python2urdf

可能会出现以下报错，根据报错进行修改后重复运行python json2urdf.py

这时候报错1：

Traceback (most recent call last):File "/mnt/d/sdc/liutong/codes/articulated-pose/tools/json2urdf.py", line 62, in <module>all_objs     = os.listdir( base_path  + dataset  + '/objects' )
FileNotFoundError: [Errno 2] No such file or directory: '/mnt/d/sdc/liutong/codes/articulated-pose/dataset/shape2motion/objects'
(gapartnet) root@szu-SYS-7048GR-TR:/mnt/d/sdc/liutong/codes/articulated-pose/tools# ls -l ../dadtaset/shape2motion

经检查，是Shape2Motion下没有objects文件夹，所以我将报错的62行进行更改如下，确保这部分可以正常运行：

# 从
all_objs     = os.listdir( base_path  + dataset  + '/objects' )
# 更改至
all_objs     = os.listdir( base_path  + dataset )

同理，73行中的路径代码因为也有objects，所以肯定也会出问题，同样进行修改：

# 从
instances_per_obj = sorted(glob.glob(base_path  + dataset  + '/objects/' + obj_name + '/*'))
# 更改至
instances_per_obj = sorted(glob.glob(base_path  + dataset + '/' + obj_name + '/*'))

接着会报错2：

Traceback (most recent call last):File "/mnt/d/sdc/liutong/codes/articulated-pose/tools/json2urdf.py", line 87, in <module>with open(json_name[0]) as json_file:
IndexError: list index out of range

这是因为前面运行的时候在dataset/shape2motion/下生成了一个urdf文件夹，这里面是生成的结果，所以会导致读取不到.json文件，所以只需要执行：

rm -rf dataset/shape2motion/urdf

即可。或者一劳永逸地改掉urdf的保存路径（前面的更改我没有把旧代码删掉，而注释旧代码，在下面添加新代码，所以我这里保存路径是在85行）。这里有个小小的担心是会不会后续条件下也要对urdf的路径进行修改：

# 从
save_dir     = base_path + '/' + dataset  + '/urdf/{}/{}'.format(obj_name, instance_name) # todo
# 更改至
save_dir     = base_path + 'urdf/{}/{}'.format(obj_name, instance_name)

接着会报错3：

Traceback (most recent call last):File "/mnt/d/sdc/liutong/codes/articulated-pose/tools/json2urdf.py", line 224, in <module>f.write('{}/{}\t'.format(obj_j['revolute'], obj_j['prismatic']))
KeyError: 'revolute'

发现是因为有的obj_j为空造成的，故更改如下：

# 从
with open(base_path + '/' + dataset + '/statistics.txt', "a+") as f:for obj_j in object_joints:f.write('{}/{}\t'.format(obj_j['revolute'], obj_j['prismatic']))f.write('\n')
# 更改至
with open(base_path + '/' + dataset + '/statistics.txt', "a+") as f:for obj_j in object_joints:if not len(obj_j) == 0:f.write('{}/{}\t'.format(obj_j['revolute'], obj_j['prismatic']))else:f.write('NAN/NAN\t')f.write('\n')

虽然ANSCH后续还有一些渲染数据的操作，但是这里我们只需要拿到URDF就足够了

1-2. URDF2OBJ

在这一步，我follow了一个已经写好的github代码：urdf_to_obj
由于我们得到的文件形式是这样的：
在这里插入图片描述

我们要取的是这下边的syn.urdf来进行最终结果的合成，我根据这个文件格式改了一下我上面提及的github的代码，更改后的代码urdf_to_obj如下，参数释义：
--urdf_file_dir：urdf文件夹的路径
--output_dir：输出文件夹的路径
--angle：用于给输出obj文件命名时候用的，你生成的是多少度就写多少度就好了（并不是在这里指定角度就能够实现生成）

from urdfpy import URDF
import numpy as np
import trimesh
import argparse
import meshes_extracted
import osdef merge_meshes(mesh_list):"""Merge a list of meshes into a single meshParameters:- mesh_list (list): list of trimesh.Trimesh objectsReturns:- mesh (trimesh.Trimesh): merged mesh"""# Get vertices and facesverts_list = [mesh.vertices for mesh in mesh_list]faces_list = [mesh.faces for mesh in mesh_list]# Num of faces per meshfaces_offset = np.cumsum([v.shape[0] for v in verts_list], dtype=np.float32) # Compute offset for faces, otherwise they all start from 0faces_offset = np.insert(faces_offset, 0, 0)[:-1]            verts = np.vstack(verts_list)faces = np.vstack([face + offset for face, offset in zip(faces_list, faces_offset)])# Create single meshmesh = trimesh.Trimesh(verts, faces)return meshdef main(args):"""Extract meshes from a URDF file and save them as .obj files"""# Load urdf file dirurdf_file_dir = args.urdf_file_diroutput_dir = args.output_dir# Load other parametersobject_angle = args.angle# Get the sub_dir under urdf_file_dir, and then 0001/0002/0003/0004/0005urdf_root = sorted(os.listdir(urdf_file_dir))for urdf_dir in urdf_root:# urdf_file_path be like 0001/syn.urdf, 0002/syn.urdf, 0003/syn.urdf, etcurdf_file_path = os.path.join(urdf_file_dir, urdf_dir, 'syn.urdf')output_path = os.path.join(output_dir, f'{urdf_dir}art{object_angle}.obj')# Load urdf filerobot = URDF.load(urdf_file_path)meshes = robot.visual_trimesh_fk()mesh_list = []for idx, mesh in enumerate(meshes):pose = meshes[mesh]   # 4 x 4 : rotation + translationtranslation = pose[:3, 3][:, None]# Add a column of zeros to the verticesverts = np.array(mesh.vertices)zeros = np.zeros((verts.shape[0], 1))new_verts = np.hstack((verts, zeros))# Apply pose to the verticesverts_pose = pose @ new_verts.transpose(1, 0) verts_pose = verts_pose[:3, :] + translation   verts_pose = verts_pose.transpose(1, 0)mesh_extracted = trimesh.Trimesh(verts_pose, mesh.faces)mesh_list.append(mesh_extracted)# Merge meshesmesh_merged = merge_meshes(mesh_list)# Save merged meshesprint('save ' + str(output_path))trimesh.exchange.export.export_mesh(mesh_merged, output_path, file_type='obj')if __name__=='__main__':parser = argparse.ArgumentParser()parser.add_argument("--urdf_file_dir", default='', type=str, help="Path to the .urdf file", required=True)parser.add_argument("--output_dir", default='', type=str, help="Path to the output dir", required=True)parser.add_argument("--angle", default='', type=str, help="Angle of objects, be used to name the file", required=True)args = parser.parse_args()main(args)

运行示例：

 python urdf_to_obj_group.py --urdf_file_dir /mnt/d/sdc/liutong/codes/articulated-pose/dataset/shape2motion/urdf/door --output_dir obj_tmp --angle 90

报错如下：

Traceback (most recent call last):File "urdf_to_obj_group.py", line 104, in <module>main(args)File "urdf_to_obj_group.py", line 56, in mainrobot = URDF.load(urdf_file_path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 3729, in loadreturn URDF._from_xml(node, path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 3926, in _from_xmlkwargs = cls._parse(node, path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 161, in _parsekwargs.update(cls._parse_simple_elements(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 137, in _parse_simple_elementsv = [t._from_xml(n, path) for n in vs]File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 137, in <listcomp>v = [t._from_xml(n, path) for n in vs]File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 181, in _from_xmlreturn cls(**cls._parse(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 161, in _parsekwargs.update(cls._parse_simple_elements(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 137, in _parse_simple_elementsv = [t._from_xml(n, path) for n in vs]File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 137, in <listcomp>v = [t._from_xml(n, path) for n in vs]File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 1146, in _from_xmlkwargs = cls._parse(node, path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 161, in _parsekwargs.update(cls._parse_simple_elements(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 127, in _parse_simple_elementsv = t._from_xml(v, path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 181, in _from_xmlreturn cls(**cls._parse(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 161, in _parsekwargs.update(cls._parse_simple_elements(node, path))File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 127, in _parse_simple_elementsv = t._from_xml(v, path)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/urdf.py", line 581, in _from_xmlmeshes = load_meshes(fn)File "/home/liutong/anaconda3/envs/gapartnet/lib/python3.8/site-packages/urdfpy/utils.py", line 235, in load_meshesraise ValueError('At least one mesh must be pmeshesent in file')
ValueError: At least one mesh must be pmeshesent in file

其实使用原始github连接中的python urdf_to_obj.py --urdf_path relative/path/to/urdf来进行试验的话，会发现0001的syn.urdf文件会报这样的错误，而0002的syn.urdf文件就不会报这样的错误。
经过仔细地检查发现，实际上是因为0001的syn.urdf中，mesh - none_motion.obj的vertices数量为空所导致的，但是因为这个错误是包里的错误，所以我也不知道应该怎么进行修改比较合适。
最后我是直接删掉会产生这个异常的文件夹，最后不会产生异常的文件夹应该只有51个。

2. Manifold to create watertight meshes

这一步实际上就是缩减网格数量，因为原本的网格太密集了
follow这个github: Manifold
follow里面的Install进行安装就可以了
然后我根据它的命令，用python写了一个自动执行减少网格数量的程序，其中要用到的参数如下：
--obj_file_dir：放置了URDF2OBJ的那些obj文件的文件夹
--target_dir：输出文件夹路径

import os
import argparse# res = os.popen('ls').read()
# print(res)def main(args):# Load obj file dirobj_file_dir = args.obj_file_dirtarget_dir = args.target_dirobj_files = sorted(os.listdir(obj_file_dir))for obj in obj_files:source_obj = os.path.join(obj_file_dir, obj)obj = "manifold_" + objtarget_obj = os.path.join(target_dir, obj)res = os.popen('./manifold ' + source_obj + ' ' + target_obj).read()print(res)if __name__=='__main__':parser = argparse.ArgumentParser()parser.add_argument("--obj_file_dir", default='', type=str, help="Path to the .obj file dir", required=True)parser.add_argument("--target_dir", default='', type=str, help="Path to the target dir", required=True)args = parser.parse_args()main(args)

这是得到的结果：
在这里插入图片描述

3. modified mesh_to_sdf for generating sampled points and sdf values

follow 这个github: mesh_to_sdf
按照里面的步骤安装好
这一步实际上就是做sdf采样了，像A-SDF里的话采样好像是保存成一些.npy还是.npz文件的，但是我这里根据我自己的需要，需要采样并保存到.mat文件中，下面提供一个保存到.mat文件中的代码：
--manifold_obj_dir: 上一步manifold减少网格数量后的结果
--sdf_dir: .mat文件的保存路径

from mesh_to_sdf import sample_sdf_near_surfaceimport trimesh
import numpy as np
import os
import argparse
from scipy.io import savemat
os.environ['PYOPENGL_PLATFORM'] = 'egl'def main(args):# Load obj file dirmanifold_obj_dir = args.manifold_obj_dirsdf_dir = args.sdf_dirmanifold_objs = sorted(os.listdir(manifold_obj_dir))for obj in manifold_objs:# Load meshmesh = trimesh.load(os.path.join(manifold_obj_dir, obj))# sample pointsprint("Now processing " + str(os.path.join(manifold_obj_dir, obj)))points, sdf, gradients = sample_sdf_near_surface(mesh, number_of_points=500000, return_gradients=True)# construct save pathtarget_file = os.path.join(sdf_dir, obj.split('.')[0].split('_')[1] + '.mat')# if only points and sdf# sdf = sdf[:, np.newaxis]# result = np.hstack((points, sdf))result = np.hstack((points, gradients))print("Saving to " + str(os.path.join(sdf_dir, obj.split('.')[0].split('_')[1] + '.mat')) + ", shape:" + str(result.shape))data = {}# data.update({'p_sdf':result})data.update({'p':result})savemat(target_file, data)if __name__=='__main__':parser = argparse.ArgumentParser()parser.add_argument("--manifold_obj_dir", default='', type=str, help="Path to the .obj file dir", required=True)parser.add_argument("--sdf_dir", default='', type=str, help="Path to the .mat dir", required=True)args = parser.parse_args()main(args)