3D topographic maps combining IMG and DEM files

Hello everybody,

I have a data set of IMG files that are used by Basecamp. This map is 2D.

I also have the DEM files for the same area.

Is there a way to combine those in Basecamp in order to have a 3D topographic map?

After researching, I do not think so but I would love to be wrong.

Are there any 3rd-party software that allow me to do this so that I can create my own 3D topo map and then use it later in Basecamp? If such gems do exists, which one would be the easiest to use?

Thanks.