SurfConv

Surface mesh converter supporting UGRID, VTK, STL, Pointwise FACET, and Tecplot formats.

Supported Formats

Format	Extension	Read	Write	Notes
UGRID	.ugrid	Yes	Yes	Triangles and quads
VTK Legacy	.vtk	Yes	Yes	ASCII unstructured grid
VTK XML	.vtu	Yes	Yes	XML unstructured grid
STL ASCII	.stl	Yes	Yes	Triangles only (default)
STL Binary	.stl	Yes	Yes	Triangles only (--format stl-binary)
FACET	.facet	Yes	Yes	Pointwise format
Tecplot	.dat	Yes	Yes	ASCII finite element

Requirements

• Python 3.6+
• NumPy

Usage

Unified Converter

Convert between any supported formats:

# Format auto-detected from extensions
python surfconv.py input.ugrid output.vtu
python surfconv.py mesh.stl mesh.facet
python surfconv.py model.vtu model.ugrid

# Specify output format (generates filename automatically)
python surfconv.py mesh.ugrid --format stl      # Creates mesh.stl
python surfconv.py mesh.ugrid --format stl-binary

# Override format detection
python surfconv.py input.dat output.dat --input-format ugrid --output-format vtk

Python API

from surfconv import read_mesh, write_mesh, convert, SurfaceMesh

# Simple conversion
convert('input.ugrid', 'output.vtu')

# Read and manipulate mesh
mesh = read_mesh('input.ugrid')
print(f"Vertices: {len(mesh.vertices)}")
print(f"Triangles: {len(mesh.triangles)}")
print(f"Quads: {len(mesh.quads)}")

# Write to different format
write_mesh(mesh, 'output.stl')

# Get all faces as triangles (quads split)
all_tris = mesh.all_triangles()

Notes

• Quad elements are preserved when converting between formats that support them (UGRID, VTK, FACET, Tecplot)
• STL only supports triangles; quads are automatically split into two triangles
• Index conversion between 0-based and 1-based formats is handled automatically