FOSSILFOrtran Stereo Litography parser

A pure Fortran 2003+ OOP library for reading, writing, and manipulating STL mesh files.

Guide

API Reference

View on GitHub

📂

STL I/O

Load and save ASCII or binary STL files. Format is auto-detected — no flags required.

🔧

Surface Manipulation

Translate, rotate, mirror, resize, clip, and merge STL surfaces with a clean type-bound API.

🩺

Surface Analysis

Compute volume, centroid, connectivity, bounding box, watertightness, and disconnected edges.

⚡

AABB Acceleration

Octree Axis-Aligned Bounding Box tree speeds up distance and point-in-polyhedron queries by up to 7×.

🧪

OOP / TDD Designed

Three clean types — file_stl_object, surface_stl_object, facet_object — each tested individually.

🆓

Free & Open Source

Multi-licensed — GPLv3 for FOSS projects, BSD 2/3-Clause or MIT for commercial use. Fortran 2003+ standard compliant.

Quick start

Load an STL file, print its statistics, and translate it:

fortran

use fossil
use penf, only: R8P
use vecfor, only: vector_R8P

type(file_stl_object)    :: file_stl
type(surface_stl_object) :: surface

! Load (ASCII or binary, auto-detected)
call file_stl%load_from_file(facet=surface%facet, file_name='cube.stl', guess_format=.true.)
call surface%analize

! Print statistics
print '(A)', file_stl%statistics()
print '(A)', surface%statistics()

! Translate and save
call surface%translate(x=1.0_R8P, y=2.0_R8P, z=0.5_R8P)
call file_stl%save_into_file(facet=surface%facet, file_name='cube-moved.stl')

Authors

Stefano Zaghi — @szaghi

Contributions are welcome — see the Contributing page.

Copyrights

FOSSIL is distributed under a multi-licensing system:

Use case	License
FOSS projects	GPL v3
Closed source / commercial	BSD 2-Clause
Closed source / commercial	BSD 3-Clause
Closed source / commercial	MIT

Anyone interested in using, developing, or contributing to FOSSIL is welcome — pick the license that best fits your needs.