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Quick Start

Get started with mmgpy in 5 minutes.

Your First Remesh

The simplest way to use mmgpy is to load a mesh, remesh it, and save the result:

import pyvista as pv
import mmgpy  # noqa: F401  -- registers the .mmg accessor + Medit reader/writer

# Load a mesh from any supported format
mesh = pv.read("input.mesh")

# Remesh with a target edge size
remeshed = mesh.mmg.remesh(hmax=0.1)

print(f"Vertices: {mesh.n_points} -> {remeshed.n_points}")
print(f"Cells:    {mesh.n_cells} -> {remeshed.n_cells}")

# Save to any supported format
remeshed.save("output.vtk")

Using Options Objects

For more control, use typed options objects with IDE autocomplete:

import pyvista as pv
from mmgpy import Mmg3DOptions

mesh = pv.read("volume.mesh")

opts = Mmg3DOptions(
    hmin=0.01,       # Minimum edge size
    hmax=0.1,        # Maximum edge size
    hausd=0.001,     # Geometric approximation tolerance
    verbose=1,       # Show progress
)

remeshed = mesh.mmg.remesh(opts)

import pyvista as pv
from mmgpy import Mmg2DOptions

mesh = pv.read("planar.mesh")

opts = Mmg2DOptions(
    hmin=0.01,
    hmax=0.1,
    verbose=1,
)

remeshed = mesh.mmg.remesh(opts)

import pyvista as pv
from mmgpy import MmgSOptions

mesh = pv.read("surface.stl")

opts = MmgSOptions(
    hmin=0.01,
    hmax=0.1,
    hausd=0.001,
    verbose=1,
)

remeshed = mesh.mmg.remesh(opts)

Factory Presets

Options classes provide convenient factory methods for common use cases:

from mmgpy import Mmg3DOptions

# Fine mesh (small elements)
fine_opts = Mmg3DOptions.fine(hmax=0.01)

# Coarse mesh (large elements)
coarse_opts = Mmg3DOptions.coarse(hmax=1.0)

# Optimization only (no topology changes)
opt_opts = Mmg3DOptions.optimize_only()

Local Sizing Control

Refine the mesh in specific regions:

import pyvista as pv
import mmgpy  # noqa: F401

mesh = pv.read("input.mesh")

remeshed = mesh.mmg.remesh(
    hmax=0.1,
    verbose=-1,
    local_sizing=[
        {
            "shape": "sphere",
            "center": (0.5, 0.5, 0.5),
            "radius": 0.2,
            "size": 0.01,
        },
        {
            "shape": "box",
            "bounds": [[0, 0, 0], [0.3, 0.3, 0.3]],
            "size": 0.02,
        },
    ],
)

PyVista Visualization

Visualize meshes with PyVista's plot() method:

import pyvista as pv
import mmgpy  # noqa: F401

# Load and remesh
mesh = pv.read("input.mesh")
remeshed = mesh.mmg.remesh(hmax=0.1)

# Quick visualization with edges
remeshed.plot(show_edges=True)

# Or customize with PyVista options
remeshed.plot(color="lightblue", opacity=0.8)

For custom plotters, use the dataset directly:

plotter = pv.Plotter()
plotter.add_mesh(remeshed, show_edges=True)
plotter.show()

Remesh from PyVista geometry:

import pyvista as pv
import mmgpy  # noqa: F401

# Create a PyVista mesh
sphere = pv.Sphere(radius=1.0)

# Remesh and visualize directly via the accessor
remeshed = sphere.mmg.remesh(hmax=0.1)
remeshed.plot(show_edges=True)

Mesh Validation

Check mesh quality before and after remeshing:

import pyvista as pv
import mmgpy  # noqa: F401

mesh = pv.read("input.mesh")

# Quick validation (returns bool)
if mesh.mmg.validate():
    print("Mesh is valid")
else:
    print("Mesh has issues")

# Detailed validation report
report = mesh.mmg.validate(detailed=True)
print(f"Valid: {report.is_valid}")
print(f"Mean quality: {report.quality.mean:.3f}")
print(f"Min quality: {report.quality.min:.3f}")

for issue in report.issues:
    print(f"  {issue.severity}: {issue.message}")

Next Steps