STL (Stereolithography）
Nov 5,2025

GISBox is a one-stop 3D GIS data editing, conversion and publishing platform that supports editing in multiple GIS formats such as OSGB/GEOTIFF/RVT, converting to 3DTiles/Terrain and publishing.

Introduction

STL (StereoLithography) is a file format developed by 3D Systems for 3D printing and computer-aided design. It is widely used in the fields of rapid prototyping and computer-aided manufacturing (CAM).

Data Format

The data formats of STL mainly include the following two types:

ASCII format: recorded in text format, including multiple definitions such as solid, facet, loop, etc. The information of each triangular face usually includes the normal vector and the coordinates of three vertices (each coordinate is a floating point number).
Binary format: Contains the file header (80 bytes), the number of facets (4 bytes), and the normal vector and vertex coordinates of each facet. Each facet data occupies 50 bytes, and finally contains 2 bytes of attribute data.

Pros

Simple and easy-to-understand file structure, easy to generate and parse.
Widely compatible with a variety of 3D printing software and hardware, becoming the de facto standard for rapid prototyping systems.
Suitable for fast export and slicing processing, improving design efficiency.

Cons

It only stores geometric information, not surface color and texture data, which limits the expressiveness of the model.
The mesh redundancy problem may cause the same vertex to be stored repeatedly in multiple faces, increasing the file size.
For complex models, the triangulation density of STL directly affects the accuracy of printing.

Application Scenario

The STL file format is widely used in 3D printing, CAD model exchange, and other fields that require three-dimensional solid models. Designers and engineers can use various CAD software (such as AutoCAD, SolidWorks, etc.) to generate STL files for subsequent printing or other processing.