LAMMPS can produce on-the-fly JPG or PNG snapshot images via its dump image command. However for high-quality, interactive visualization, you need tools like those discussed on this page.
These are high-quality visualization packages we have used. LAMMPS can either write output files directly in an input format recognized by these programs (see the dump command), or auxiliary tools may be included in the distribution to convert to the needed format:
Our group has also written and released a toolkit called Pizza.py which provides tools for doing LAMMPS pre- and post-processing, and which includes a simple OpenGL-based visualization tool called gl. Pizza.py is written in Python, is available on GitHub or for download from this page. It includes Python wrappers that drive the Raster3d and RasMol packages listed above. It also includes tools that convert LAMMPS output into input files readable by VMD and AtomEye.
These are visualization tools we know less about, but which have features that may be attractive to LAMMPS users. Some details are given below:
Guido Germano (Philipps-Universitaet Marburg) sent a link to his freely-available package QMGA which does OpenGL rendering of non-spherical (and spherical) objects. This could be useful for visualization of aspherical particles simulated with LAMMPS.
VisIt is a general purpose visualization package developed at LLNL and has support for LAMMPS dump file formats as explained here