Trimesh介绍及基本使用

Trimesh是一个纯Python 工具库（支持3.7版本以上），用于加载和使用三角形Mesh网格，支持多种常见的三维数据格式，如二进制/文本格式的STL、Wavefront OBJ、二进制/文本格式的PLY、GLTF/GLB 2.0、3MF、XAML、3DXML等输入及输出。

Trimesh自带可视化接口，同时支持jupyter-notebook

conda安装Trimesh

conda install -c conda-forge trimesh

官方介绍 https://trimesh.org/install.html

Trimesh的基本使用

# trimesh
import trimesh
import numpy as np

1、三维模型加载模型并显示

Import meshes from binary/ASCII STL, Wavefront OBJ, ASCII OFF, binary/ASCII PLY, GLTF/GLB 2.0, 3MF, XAML, 3DXML, etc.
Export meshes as binary STL, binary PLY, ASCII OFF, OBJ, GLTF/GLB 2.0, COLLADA, etc.

# 加载3D模型, stl/obj
mesh = trimesh.load_mesh('assets/T520.obj')
mesh.show()

2、获取模型的数据

1）顶点数据

# 顶点数值
mesh.vertices, len(mesh.vertices)

(TrackedArray([[ 7.69345e-01, -1.68524e-01, -5.17700e-03],[ 7.95310e-01, -1.30030e-01, -1.49920e-02],[ 7.96241e-01, -2.50368e-01,  7.82000e-04],[ 7.89202e-01, -2.47317e-01, -1.20380e-02],
...[-7.28633e-01, -4.08450e-02, -2.48030e-02],[-7.75898e-01, -7.34740e-02, -1.63650e-02]]),252)

2）三角面片数据

# 具体的三角面片数值
mesh.triangles, mesh.triangles.shape

(array([[[ 0.706239, -0.098673, -0.017216],[ 0.691089, -0.012151, -0.031851],[ 0.632243, -0.153526, -0.011587]],[[-0.072159, -0.088825, -0.011398],[-0.103937, -0.111302, -0.012344],[-0.11107 , -0.110316, -0.043356]],[[ 0.22723 , -0.144808, -0.022788],[ 0.174921, -0.039651, -0.027571],[ 0.160237, -0.11074 ,  0.001933]],...,[[-0.188532, -0.037858, -0.043866],[-0.156491,  0.026905, -0.063014],[-0.249915,  0.023218, -0.060589]],[[ 0.769345, -0.168524, -0.005177],[ 0.79531 , -0.13003 , -0.014992],[ 0.764495, -0.065438, -0.018574]],[[ 0.764495, -0.065438, -0.018574],[ 0.716619, -0.036048, -0.035477],[ 0.758556, -0.016973, -0.031903]]]),(500, 3, 3))

3）获取三角面的索引

# 三角面索引
mesh.faces, mesh.faces.shape

(TrackedArray([[  8,   7,  15],[172, 192, 194],[ 53,  58,  65],...,[207, 204, 205],[  0,   1,   4],[  4,   5,   6]]),(500, 3))

4）获取法向

# 法向
mesh.face_normals, mesh.face_normals.shape

(array([[-0.0430527 ,  0.15929062,  0.98629253],[ 0.57338015, -0.80401884, -0.15744496],[ 0.44854726,  0.26199037,  0.85449775],...,[ 0.01400081,  0.27712567,  0.96073167],[ 0.16915266,  0.13484063,  0.97632238],[ 0.18972766, -0.23867821, -0.95238444]]),(500, 3))

5）面角度

mesh.face_angles, mesh.face_angles.shape

(array([[2.0388429 , 0.56233828, 0.54041148],[0.60782991, 1.76058396, 0.77317879],[0.72379323, 0.73242608, 1.68537335],...,[1.21296721, 1.08268034, 0.84594511],[0.63579868, 2.10158121, 0.40421277],[0.86144328, 0.98109206, 1.29905732]]),(500, 3))

6）面片面积

mesh.area_faces, mesh.area_faces.shape

(array([0.00366692, 0.00060866, 0.00307942, 0.00190347, 0.00148136,0.00144005, 0.00038739, 0.00108227, 0.00081048, 0.00068454,0.00144096, 0.00436192, 0.00092929, 0.00109818, 0.00200931,0.00293418, 0.00155164, 0.00069498, 0.00211061, 0.00245476,
...0.00041811, 0.00288816, 0.00024923, 0.00102368, 0.00124401,0.00203138, 0.00155559, 0.0017429 , 0.00130824, 0.00059137,0.00061473, 0.00168217, 0.00308738, 0.00146638, 0.00112652]),(500,))

7）总面积、总体积、最大最小点(aabb包围盒)、实体数量

# 边界包围盒
mesh.area, mesh.volume,mesh.bounds,mesh.body_count

(1.170476162025276,0.018943660462617348,array([[-0.797947, -0.333213, -0.095076],[ 0.796241,  0.442033,  0.285582]]),1)

3、导出模型

导出模型
mesh.export('output/export-models.stl')