MMG Parameters Reference¶

Complete reference for all MMG remeshing parameters.

Size Parameters¶

hmin¶

Minimum edge length.

Property	Value
Type	`float`
Default	Auto-computed
Range	> 0

result = mesh.remesh(hmin=0.01)

Edges shorter than hmin will be collapsed or lengthened.

hmax¶

Maximum edge length.

Property	Value
Type	`float`
Default	Auto-computed
Range	> hmin

result = mesh.remesh(hmax=0.1)

Edges longer than hmax will be split.

hsiz¶

Uniform target edge size.

Property	Value
Type	`float`
Default	None
Range	> 0

result = mesh.remesh(hsiz=0.05)

When set, overrides hmin and hmax with uniform sizing.

hgrad¶

Gradation parameter controlling size transition.

Property	Value
Type	`float`
Default	1.3
Range	>= 1.0

result = mesh.remesh(hgrad=1.2)

hgrad=1.0: No size variation allowed
hgrad=1.3: Default, allows 30% size change between adjacent edges
hgrad=2.0: Large size variations allowed

Geometric Parameters¶

hausd¶

Hausdorff distance - maximum distance between input and output geometry.

Property	Value
Type	`float`
Default	0.01 * bounding box diagonal
Range	> 0

result = mesh.remesh(hausd=0.001)

Smaller values = better geometric approximation but more elements.

angle¶

Ridge detection angle in degrees.

Property	Value
Type	`float`
Default	45.0
Range	0 - 180

result = mesh.remesh(angle=30.0)

Edges with dihedral angle > angle are treated as ridges
Ridges are preserved during remeshing
angle=180: No ridge detection

Control Flags¶

optim¶

Enable optimization mode.

Property	Value
Type	`int`
Default	0
Values	0 (off), 1 (on)

result = mesh.remesh(optim=1)

When enabled, only moves vertices to improve quality (no topology changes).

noinsert¶

Disable vertex insertion.

Property	Value
Type	`int`
Default	0
Values	0 (off), 1 (on)

result = mesh.remesh(noinsert=1)

Prevents adding new vertices during remeshing.

noswap¶

Disable edge/face swapping.

Property	Value
Type	`int`
Default	0
Values	0 (off), 1 (on)

result = mesh.remesh(noswap=1)

Prevents topology changes via edge/face swaps.

nomove¶

Disable vertex movement.

Property	Value
Type	`int`
Default	0
Values	0 (off), 1 (on)

result = mesh.remesh(nomove=1)

Keeps vertices at their original positions.

nosurf¶

Preserve surface vertices.

Property	Value
Type	`int`
Default	0
Values	0 (off), 1 (on)

result = mesh.remesh(nosurf=1)

Prevents modification of surface mesh vertices.

Output Control¶

verbose¶

Verbosity level.

Property	Value
Type	`int`
Default	1
Range	-1 to 10

result = mesh.remesh(verbose=-1)  # Silent
result = mesh.remesh(verbose=0)   # Errors only
result = mesh.remesh(verbose=1)   # Standard info
result = mesh.remesh(verbose=5)   # Debug output

Common Combinations¶

Quality Optimization Only¶

result = mesh.remesh(optim=1, noinsert=1)

Or use the convenience method:

result = mesh.remesh_optimize()

Uniform Remeshing¶

result = mesh.remesh(hsiz=0.05)

Or use the convenience method:

result = mesh.remesh_uniform(size=0.05)

High-Quality Surface Approximation¶

result = mesh.remesh(
    hmax=0.1,
    hausd=0.0001,  # Tight geometric tolerance
    hgrad=1.1,     # Smooth size transition
)

Preserve Sharp Features¶

result = mesh.remesh(
    hmax=0.1,
    angle=20.0,  # Detect more ridges
    hausd=0.001,
)

Fast Coarse Remeshing¶

result = mesh.remesh(
    hmax=0.5,
    hgrad=2.0,  # Allow large size variations
    verbose=-1,
)

Volume Interior Only¶

result = mesh.remesh(
    hmax=0.1,
    nosurf=1,  # Keep surface fixed
)

Parameter Interactions¶

Parameters	Effect
`optim=1, noinsert=1`	Quality optimization only
`hmin=hmax`	Near-uniform sizing
`hausd` small + `hmax` large	More elements on surface
`angle=180`	No ridge preservation
`hgrad=1.0`	No size gradation

Best Practices¶

Start with defaults: MMG auto-computes reasonable defaults
Set hmax first: Most important parameter
Add hausd for surfaces: Controls geometric fidelity
Tune hgrad: Lower for smoother transitions
Use verbose=-1: For batch processing
Validate results: Always check mesh quality after remeshing