STLModel

C++: phynexis::utils::STLModel Python: phynexis.utils.STLModel Header: src/utils/mesh/stl_model.hpp

3D triangle mesh model supporting STL/OFF file I/O, geometric transformations, decimation, convex hull, and mesh analysis.

Constructor

STLModel()

Creates an empty model.

STLModel(vertices, facets)

Creates a model from vertex and face arrays.

Parameters:

Parameter	Type	Description
vertices	list[Vec3d]	Vertex positions
facets	list[Vec3i]	Triangle face indices

STLModel(file_path)

Load from a file path (auto-detects format).

Properties

Property	Type	Description
vertices	list[Vec3d]	Model vertices (read/write)
facets	list[Vec3i]	Triangle face indices (read/write)

Methods

init_from_stl(file_path) / init_from_off(file_path)

Load from STL or OFF file.

save_to(path, file, options)

Save model to file with format options.

load_from(path, file, opt=LoadOptions())

Load model from file with load options.

Parameters:

Parameter	Type	Description
path	str	Directory path
file	str	File name
opt	LoadOptions	Load options (create_directories, format_hint)

transpose() / rotate(rotation)

Apply geometric transformations.

copy_pose() / copy_pose_dev()

Copy the model's current pose.

remove_unreferenced_vertices() / remove_duplicate_vertices()

Clean up mesh topology.

reorient_facets()

Ensure facet normals point outward.

decimate(target_num_faces)

Reduce face count via mesh decimation.

standardize()

Center at origin and scale to unit size.

set_size(size)

Scale to a specific size.

make_convex()

Convert to convex hull.

refine() / smooth_mesh(iterations)

Subdivide or smooth the mesh.

merge(other_model)

Merge with another STLModel.

size()

Return characteristic size (diagonal of bounding box).

get_center() / get_surface_area() / volume() / inertia()

Compute geometric properties.

is_convex() / is_face_outside(facet_index, point) / enclose(point)

Convexity and containment tests.

bound_aabb()

Return axis-aligned bounding box.

print_info()

Print model summary.

Static Methods

CenterOf(vertices, facets) / SurfaceAreaOf(vertices, facets) / VolumeOf(vertices, facets) / InertiaOf(vertices, facets) / check_convexity_of(vertices, facets)

Compute properties from raw mesh data without creating an STLModel instance.

Example

import phynexis

# Create a mesh from a sphere shape
model = phynexis.utils.shape.Sphere(2.0).get_stl_model(200)

print("size:", model.size())
print("center:", model.get_center())
print("volume:", model.volume())
print("surface area:", model.get_surface_area())
print("is convex:", model.is_convex())

# Transformations
model.standardize()
print("after standardize, size:", model.size())

Output:

size: 1.9814485316774066
center: Vec3d(-3.05057e-06, -1.61383e-05, -4.46186e-05)
volume: 4.073305749647874
surface area: 12.374617224062705
is convex: True
after standardize, size: 0.9999999999999999

Example: Create from vertices and facets

import phynexis

model = phynexis.utils.STLModel()
model.vertices = [
    phynexis.utils.Vec3d(0.0, 0.0, 0.0),
    phynexis.utils.Vec3d(1.0, 0.0, 0.0),
    phynexis.utils.Vec3d(0.0, 1.0, 0.0),
]
model.facets = [phynexis.utils.Vec3i(0, 1, 2)]

print("vertices:", len(model.vertices))
print("facets:", len(model.facets))
print("center:", model.get_center())
print("volume:", model.volume())
print("surface area:", model.get_surface_area())

Output:

vertices: 3
facets: 1
center: Vec3d(0.333333, 0.333333, 0)
volume: 0.0
surface area: 0.5

Mesh I/O Functions

Top-level functions for reading and writing mesh files.

read(filename)

Read a mesh from an STL file.

Parameters:

Parameter	Type	Description
filename	str	Path to STL file

Returns: STLModel

read_off(filename)

Read a mesh from an OFF file.

Parameters:

Parameter	Type	Description
filename	str	Path to OFF file

Returns: STLModel

write_off(filename, model)

Write an STLModel to an OFF file.

Parameters:

Parameter	Type	Description
filename	str	Output OFF file path
model	STLModel	Model to save

Example:

import phynexis

# Read STL
model = phynexis.utils.read("/Users/lzhshou/Documents/myResearch/myProjects/apaam/repo/phynexis/data/sphere.stl")
print("vertices:", len(model.vertices), "facets:", len(model.facets))

# Write OFF
phynexis.utils.write_off("/tmp/sphere.off", model)

Output:

vertices: 162
facets: 320

Unexposed C++ API

• get_triangle_strips() — return type not fully exposed

Visual Preview

Export the mesh to VTK and view it with any VTK-compatible viewer:

import phynexis

model = phynexis.utils.shape.Sphere(2.0).get_stl_model(200)
opts = phynexis.utils.SaveOptions()
opts.overwrite = True
model.save_to('/tmp/', 'stl_preview.vtk', opts)

STLModel visual preview

STLModel with edges (parallel projection)