The effect of the step point on the boundary

In the particle transport process of Geant4, there must be a step point at the boundary between the two volumes. Will these step points generated between the boundary of the two volumes affect the simulation results? In other words, if I represent the geometry I want to create with a number of voxels in the Geant4 simulation, do I need to merge the voxels that have exactly the same material into one volume (i.e. delete the boundaries between them)?
Another related question, about limiting step length, how do I determine if I need to limit step length? Is the simulation more reliable if the step length is shorter?

I remember reading a hint in the documentation related to this…

G4RegularNavigation - provides location and distance computation functions for fast navigation in volumes containing a regular parameterisation. If two contiguous voxels have the same material, navigation does not stop at the surface.

https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/Detector/Geometry/geomNav.html?#the-geometry-navigator

so maybe you could use a regular parametrisation and do not need to worry about collapsing same material voxels?!

  • Thank you for your reply, which is very helpful to me.