# Modifiers

Modifiers are the basic building blocks that can be used in OVITO's modification pipeline. The following table lists the available modifier types.

Modifier name | Description
--- | ---
Analysis
Atomic strain | Calculates the atomic-level strain tensors based on an initial reference and a deformed configuration.
Bin and reduce | Agregates a particle property over a one- or two-dimensional bin grid.
Bond-angle analysis | Performs the bond-angle analysis of Ackland and Jones to determine the local crystal structure.
Construct surface mesh | Constructs a polyhedral mesh representing the surface of an atomistic solid.
Correlation function | Calculates the spatial cross-correlation function between two particle properties.
Dislocation analysis (DXA) | Detects dislocation lines in a crystal.
Displacement vectors | Calculates the displacements of particles based on an initial and a deformed configuration.
Centrosymmetry parameter | Calculates the centrosymmetry parameter for every particle.
Cluster analysis | Decomposes a particle system into clusters of particles.
Common neighbor analysis | Performs the common neighbor analysis (CNA) to determine the local crystal structure.
Coordination analysis | Determines the number of near neighbors of each particle and computes the radial distribution function.
Elastic strain calculation | Calculates the atomic-level elastic strain tensors in crystalline systems.
Histogram | Computes the histogram of a particle property.
Identify diamond structure | Finds atoms that are arranged in a cubic or hexagonal diamond lattice.
Polyhedral Template Matching | Identifies the local crystal structure using the PTM method.
Scatter plot | Generates a scatter plot of two particle properties.
Voronoi analysis | Computes the coordination number, atomic volume, and Voronoi index of particles from their Voronoi polyhedra.
VoroTop analysis | Identifies local structure of particles using the topology of their Voronoi polyhedra.
Wigner-Seitz defect analysis | Identifies point defects (vacancies and interstitials) in a crystal lattice.
Coloring
Ambient occlusion | Performs an ambient occlusion calculation to shade particles.
Assign color | Assigns a color to all selected particles.
Color coding | Colors particles or bonds based on a property.
Fields
Create isosurface | Constructs isosurfaces from scalar field data.
Modification
Affine transformation | Applies an affine transformation to particle coordinates.
Create bonds | Creates bonds between particles.
Combine particle sets | Merges the particles from two separate files into one dataset.
Compute bond lengths | Computes the length of each bond in the system.
Compute property | Computes a new property for each particle based a user-defined formula.
Coordination polyhedra | Shows coordination polyhedra
Delete selected particles | Deletes all selected particles.
Freeze property | Takes a snapshot of the current state of a particle property and preserves it over time.
Load trajectory | Loads time-dependent atomic positions from a separate trajectory file.
Python script | Allows you to write your own modifier type in Python..
Show periodic images | Duplicates particles to display the periodic images of particles.
Slice | Cuts out a slice or a cross-section from the structure.
Wrap at periodic boundaries | Maps particles outside of the simulation box back into the box.
Selection
Clear selection | Resets the selection state of all particles.
Expand selection | Selects particles that are neighbors of already selected particles.
Manual selection | Allows to select particles with the mouse.
Invert selection | Inverts the selection state of each particle.
Expression select | Selects particles based on a user-defined criterion.
Select particle type | Selects particles of one or more types.