Trimesh Geometry

Full-featured mesh processing with trimesh.

Installation

pip install trimesh[all]  # Full installation with optional dependencies

Loading and Saving

import trimesh

# Load mesh
mesh = trimesh.load('model.stl')

# Load with specific format
mesh = trimesh.load('model.obj', file_type='obj')

# Save mesh
mesh.export('output.stl')
mesh.export('output.ply')
mesh.export('output.glb')  # GLTF binary

Creating Primitives

import trimesh

# Box
box = trimesh.creation.box(extents=[10, 20, 5])

# Cylinder
cylinder = trimesh.creation.cylinder(radius=5, height=20)

# Sphere
sphere = trimesh.creation.icosphere(radius=10, subdivisions=3)

# Cone
cone = trimesh.creation.cone(radius=5, height=10)

# From vertices and faces
mesh = trimesh.Trimesh(vertices=vertices, faces=faces)

Boolean Operations

import trimesh

a = trimesh.creation.box(extents=[10, 10, 10])
b = trimesh.creation.cylinder(radius=3, height=20)

# Union
union = a.union(b)

# Difference
difference = a.difference(b)

# Intersection
intersection = a.intersection(b)

Transformations

import trimesh
import numpy as np

mesh = trimesh.load('model.stl')

# Translation
mesh.apply_translation([10, 0, 0])

# Rotation (4x4 matrix)
angle = np.radians(45)
rotation = trimesh.transformations.rotation_matrix(angle, [0, 0, 1])
mesh.apply_transform(rotation)

# Scaling
mesh.apply_scale(2.0)

Mesh Analysis

import trimesh

mesh = trimesh.load('model.stl')

# Properties
print(f"Vertices: {len(mesh.vertices)}")
print(f"Faces: {len(mesh.faces)}")
print(f"Volume: {mesh.volume}")
print(f"Surface area: {mesh.area}")
print(f"Center of mass: {mesh.center_mass}")
print(f"Is watertight: {mesh.is_watertight}")
print(f"Is convex: {mesh.is_convex}")

# Bounding box
print(f"Bounds: {mesh.bounds}")
print(f"Extents: {mesh.extents}")

Mesh Repair

import trimesh

mesh = trimesh.load('broken_model.stl')

# Fix normals
mesh.fix_normals()

# Fill holes
mesh.fill_holes()

# Remove degenerate faces
mesh.remove_degenerate_faces()

# Merge duplicate vertices
mesh.merge_vertices()

# Process into watertight mesh
mesh.process(validate=True)

Ray Tracing

import trimesh
import numpy as np

mesh = trimesh.load('model.stl')

# Single ray
origin = [0, 0, 100]
direction = [0, 0, -1]
locations, index_ray, index_tri = mesh.ray.intersects_location(
    ray_origins=[origin],
    ray_directions=[direction]
)

# Check if point is inside mesh
points = [[0, 0, 0], [100, 100, 100]]
inside = mesh.contains(points)

Slicing

import trimesh

mesh = trimesh.load('model.stl')

# Slice at Z=5
slice_2d = mesh.section(plane_origin=[0, 0, 5], plane_normal=[0, 0, 1])

# Get 2D path
path_2d, to_3d = slice_2d.to_planar()