Yes, you can have a public viewing prior to cremation. This does not necessarily mean the body would have to be emblamed, but there are multiple factors that need to be considered regarding embalming such as time between death and the viewing, the physical condition of the deceased and any local regulations, among other things. Generally embalming is not required, but it may be, under certain circumstances.
Your best bet is to discuss your particular situation and preferences with your local Funeral Director to make these decisions