# Modifiers

Modifiers are the basic building blocks that can be used in OVITO's processing 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.
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.
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.
Histogram | Computes the histogram of a particle property.
Scatter plot | Generates a scatter plot of two particle properties.
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 based on a certain particle property.
Modification
Affine transformation | Applies an affine transformation to particle coordinates.
Create bonds | Creates bonds between particles.
Compute property | Computes a new property for each particle based a user-defined formula.
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.
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.
Freeze selection | Preserves the current selection state over time.
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.