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  <title>Introduction</title>

  <para>
    <informalfigure><screenshot><mediaobject><imageobject>
       <imagedata fileref="images/ovito_screenshot.png" format="PNG" />
    </imageobject></mediaobject></screenshot></informalfigure>
  
  OVITO is a scientific data visualization and analysis software for
  atomistic simulation models in materials science and related disciplines.
  OVITO is freely available for
  Windows, Linux, and Mac OS X under an open-source license. It is being developed by <link xlink:href="http://scholar.google.com/citations?user=f8Tw3eEAAAAJ">Dr. Alexander
  Stukowski</link> at the <link xlink:href="http://www.mawi.tu-darmstadt.de/mm/mm_mm_sw/index.en.jsp">
  Materials Science Department</link> of Darmstadt University of Technology, Germany.
  </para>
  
  <para>
  The first version of OVITO was released in December 2009 and its initial feature set was described in 
  a <link xlink:href="http://stacks.iop.org/0965-0393/18/015012">journal article about OVITO</link> in 2010.
  Today OVITO has more than active 50,000 users from the computational physics, materials science, and chemistry fields.
  </para>
  
  <simplesect>
  <title>Program features</title>

  <para>OVITO is a software for visualizing and analyzing output data from particle-based simulation models, notably molecular dynamics (MD) simulations of 
  solid-state materials. Its main focus is on large simulation models based on classical potentials 
  (10<superscript>3</superscript> - 10<superscript>8</superscript> atoms).
  Some noteworthy program features are: <itemizedlist>

      <listitem>
        <para><link linkend="usage.import">Input</link> and <link linkend="usage.export">output</link> of various file formats used by 
        MD simulation codes, including LAMMPS, XYZ, CFG, IMD, POSCAR, NetCDF, PDB, FHI-aims, and GSD/HOOMD.</para>
      </listitem>

      <listitem>
        <para>Interactive display of large numbers of particles and bonds using hardware-accelerated OpenGL rendering.</para>
      </listitem>

      <listitem>
        <para>Support for <link linkend="howto.aspherical_particles">various particle shapes</link>: spheres, cubes, ellipsoids, cylinders, and more.</para>
      </listitem>

      <listitem>
        <para>An easy-to-use interface, a flexible software design, and a <link linkend="usage.particle_properties">data model</link> that supports an arbitrary number of particle properties.</para>
      </listitem>

      <listitem>
        <para>High-quality <link linkend="usage.rendering">image and movie rendering</link> for publication and a <link linkend="usage.animation">keyframe-based animation system</link>.</para>
      </listitem>
      
      <listitem>
        <para><link linkend="usage.scripting">A powerful Python-based scripting interface</link> 
        that allows one to automate analysis and visualization tasks 
        and <link linkend="particles.modifiers.python_script">extend OVITO</link> with new functions.</para>
      </listitem>      
      
      <listitem>
        <para><link linkend="usage.modification_pipeline">Nondestructive data manipulation and analysis functions</link> 
        are arranged in a data flow pipeline by the user. Parameters can be changed at 
        any time and results will be immediately recalculated. Available <link linkend="particles.modifiers">modification functions</link> include:<itemizedlist>

            <listitem>
              <para><link linkend="particles.modifiers.expression_select">Dynamic particle selections based on Boolean expressions</link></para>
            </listitem>

            <listitem>
              <para><link linkend="particles.modifiers.color_coding">Color coding</link></para>
            </listitem>

            <listitem>
              <para><link linkend="particles.modifiers.slice">Slicing and cutting</link></para>
            </listitem>
            
            <listitem>
              <para><link linkend="particles.modifiers.affine_transformation">Transformation of particle coordinates</link></para>
            </listitem>

            <listitem>
              <para><link linkend="particles.modifiers.compute_property">Computing new particle properties</link></para>
            </listitem>

            <listitem>
              <para><link linkend="particles.modifiers.show_periodic_images">Display of periodic images</link> &amp; <link linkend="particles.modifiers.wrap_at_periodic_boundaries">wrapping of particles at periodic boundaries</link></para>
            </listitem>
            
            <listitem>
              <para><link linkend="particles.modifiers.create_bonds">Creation of atomic bonds</link></para>
            </listitem>

            <listitem>
              <para><link linkend="particles.modifiers.manual_selection">Manual selection of particles</link> and inspection of particle properties</para>
            </listitem>
            
          </itemizedlist> 
        </para>
      </listitem>

      <listitem>
        <para>Useful analysis functions:</para>

        <itemizedlist>
          <listitem>
            <para><link linkend="particles.modifiers.common_neighbor_analysis">Common neighbor analysis (CNA)</link></para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.bond_angle_analysis">Bond-angle analysis</link></para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.centrosymmetry">Centro-symmetry parameter</link></para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.coordination_analysis">Coordination number analysis and radial distribution function</link></para>
          </listitem>
          
          <listitem>
            <para><link linkend="particles.modifiers.dislocation_analysis">Automated dislocation line identification (DXA)</link></para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.displacement_vectors">Displacement vector calculation</link></para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.atomic_strain">Atomic strain tensor calculation</link></para>
          </listitem>
          
          <listitem>
            <para><link linkend="particles.modifiers.histogram">Histogram</link> and <link linkend="particles.modifiers.scatter_plot">scatter plot</link> functions</para>
          </listitem>

          <listitem>
            <para><link linkend="particles.modifiers.construct_surface_mesh">Reconstruction of geometric surfaces from atomistic models</link></para>
          </listitem>

	      <listitem>
            <para><link linkend="particles.modifiers.voronoi_analysis">Voronoi cell analysis</link></para>
          </listitem>
          
	      <listitem>
            <para><link linkend="particles.modifiers.wigner_seitz_analysis">Identification of point defects using Wigner-Seitz cell method</link></para>
          </listitem>
          
        </itemizedlist>
         
      </listitem>
      
      <listitem>
        <para>A modular software design, which allows to extend OVITO via C++ plugins</para>
      </listitem>
      
    </itemizedlist>
    </para>
    
  </simplesect>
    
</chapter>
