tracking3d  is a module to track an arbitrary solid body  inside a computational domain. The solid body is initially represented using a level set function. It can be obtained using some geometry process modules such as rotation and stlreader in Lesimx, as shown in Figures 4 and 5. Figure 4 shows three solid bodies generated using the modules rotation and stlreader while Figure 5 shows the final solid body generated using the module booleanopt from the above mentioned solid bodies.

tracking3d gives the level set at each grid point representing the moving solid body in a computational domain. It can also provides the solid volume fraction at each cell corresponding to the tracked solid body. Figure 6 shows the solid body at three different times inside a computational domain. A video to show the movement of the solid body is here.

The solid body is tracked using the Euler parameters to generate the transformation matrix. tracking3d can be used in a third-part code as a library by calling a subroutine or run as a stand alone code.