What happens to the phase of a wave during scattering?

[Nono713]

Hi,
I can't seem to find any straightforward information on this. I know wave transmission does not change the incident wave's phase, and wave reflection shifts it by $\pi$ if the wave is reflected by a denser medium than the one it is in...

But what happens to the phase when the wave undergoes scattering? Is the phase unchanged, shifted by some constant, by some complex expression depending on the type of scattering involved and the direction of the scattered wave relative to the incident wave, or just changed randomly?

Approximations are fine, I don't need an exact solution but something tractable. This isn't for a physics class or paper but for a computer science project involving interference simulation.

Thanks!

EDIT: never mind, I've decided to ignore phase effects beyond thin-film interference and use the analytical formula for thin-film interference instead. Seems simpler this way.

 

[Ackbach]

For the record, there are types of waves, such as solitons (that is the correct spelling) propagating down a fiber optic cable, that can "bump into each other", affecting each other's phase. Solitons are an interesting quantum mechanical phenomenon, with wave-like and particle-like characteristics. However, I think it is also true that some scattering situations, perhaps even most scattering situations, do not involve a phase change.