2

I am working with openmesh installed in Python 3.6 via pip. I need to add custom properties to vertices of a mesh in order to store some data at each vertex. My code goes as follows : 

import openmesh as OM
import numpy as np
mesh = OM.TriMesh()

#Some vertices
vh0 = mesh.add_vertex(np.array([0,0,0]));
vh1 = mesh.add_vertex(np.array([1,0,0]));
vh2 = mesh.add_vertex(np.array([1,1,0]));
vh3 = mesh.add_vertex(np.array([0,1,0]));

#Some data
data = np.arange(mesh.n_vertices)

#Add custom property
for vh in mesh.vertices():
    mesh.set_vertex_property('prop1', vh, data[vh.idx()])

#Check properties have been added correctly
print(mesh.vertex_property('prop1'))

OM.write_mesh('mesh.om',mesh)

print returns [0, 1, 2, 3]. So far, so good. But when I read again the mesh, the custom property has disappeared :

mesh1 = OM.TriMesh()

mesh1 = OM.read_trimesh('mesh.om')

print(mesh1.vertex_property('prop1'))

returns [None, None, None, None]

I have two guesses :
1 - The property was not saved in the first place
2 - The reader does not know there is a custom property when it reads the file mesh.om

Does anybody know how to save and read properly a mesh with custom vertex properties with openmesh in Python? Or is it even possible (has anybody done it before?)?
Is it that there is something wrong with my code?

Thanks for your help,

Charles.

4

2 回答 2

1

OM 编写器当前不支持自定义属性。如果您使用数字属性，将数据转换为 NumPy 数组并单独保存可能是最简单的方法。

假设您的网格和属性设置如下：

import openmesh as om
import numpy as np

# create example mesh
mesh1 = om.TriMesh()
v00 = mesh1.add_vertex([0,0,0])
v01 = mesh1.add_vertex([0,1,0])
v10 = mesh1.add_vertex([1,0,0])
v11 = mesh1.add_vertex([1,1,0])
mesh1.add_face(v00, v01, v11)
mesh1.add_face(v00, v11, v01)

# set property data
mesh1.set_vertex_property('color', v00, [1,0,0])
mesh1.set_vertex_property('color', v01, [0,1,0])
mesh1.set_vertex_property('color', v10, [0,0,1])
mesh1.set_vertex_property('color', v11, [1,1,1])

您可以使用其中一种方法将属性数据提取为 numpy 数组，并使用 NumPy 的函数*_property_array将其保存在网格旁边。save

om.write_mesh('mesh.om', mesh1)
color_array1 = mesh1.vertex_property_array('color')
np.save('color.npy', color_array1)

加载类似：

mesh2 = om.read_trimesh('mesh.om')
color_array2 = np.load('color.npy')
mesh2.set_vertex_property_array('color', color_array2)

# verify property data is equal
for vh1, vh2 in zip(mesh1.vertices(), mesh2.vertices()):
    color1 = mesh1.vertex_property('color', vh1)
    color2 = mesh2.vertex_property('color', vh2)
    assert np.allclose(color1, color2)
于 2018-07-09T15:40:01.750 回答
0

存储数据时，应将 set_persistent 函数设置为 true，如下所示。（对不起使用c++，我不知道python）

OpenMesh::VPropHandleT<float> vprop_float;
mesh.add_property(vprop_float,  "vprop_float");
mesh.property(vprop_float).set_persistent(true);
OpenMesh::IO::write_mesh(mesh, "tmesh.om");

然后，您必须在使用 obj 阅读器加载网格之前在网格中请求此自定义属性。秩序很重要。

TriMesh readmesh;
OpenMesh::VPropHandleT<float> vprop_float;
readmesh.add_property(vprop_float, "vprop_float");
OpenMesh::IO::read_mesh(readmesh, "tmesh.om");'

我在下面提到。 https://www.openmesh.org/media/Documentations/OpenMesh-4.0-Documentation/a00062.html https://www.openmesh.org/media/Documentations/OpenMesh-4.0-Documentation/a00060.html

于 2019-12-23T05:42:46.633 回答