The .stl format handles 3D printing geometry by representing 3D models as a mesh of interconnected triangular facets. Each triangle, defined by three vertices and a normal vector, collectively approximates the model’s surface, allowing 3D printers to interpret shape and structure.
Key aspects of its geometry handling include: - Triangular mesh structure: Triangles act as basic units, combining to form the model’s surface; more triangles enhance detail but increase file size. - Normal vectors: Indicate each triangle’s orientation, helping printers distinguish between the model’s interior and exterior to avoid errors. - Mesh integrity: STL files must be "watertight" (no gaps/overlaps); tools like MeshLab check for non-manifold geometry to ensure printability.