Trajectory Line Analysis in MD Simulations
The trajectory line analysis produces a set of continuous lines from the time-dependent particle positions. It can be used to visualize the trajectories of motion of particles. OVITO software can produce this atomic parameter for simulated structures. By using “Generate trajectory lines” modification item in OVITO software, one can choose between generating the trajectory lines for every particle in the system or just for a subset of the particles. For the latter, simulation operator first need to insert a particle selection modifier into the data pipeline to define the selection for the trajectory line generation. The trajectory line generating process and visualizing trajectory lines for simulations with a large number of particles and/or a large number of time steps can be prohibitively expensive. Thus, it is typically a good idea to restrict the generation of trajectory lines to a small group of particles of interest. Below figure depicted trajectory line of fluid particles inside 2D nanochannel in presence of two obstacles.
Technically, the button Generate trajectory lines starts the line tracing process. OVITO software will read in all simulation frames one by one and sample the particle positions to produce the trajectory lines. The generated lines will be stored in memory, and they will be updated only when you press the button again. Below video indicated the trajectory line defining procedure of atomic structures by using OVITO software.