I'm familiar with A* and have worked it on a 2D problem (cars). I am now looking to learn about shortest path problems for a 3D space (working with flying a drone) and was hoping someone could tell me what algorithms (simplest) to look at.

I'm wanting to take off, fly to an ordered number of way points, and return.

thanks,

Like someone has said A* works in whatever domain as long as you can represent the data in a way that is compatible with running the A* algorithm on it, if you split your 3D volume into a 3D grid of nodes instead of a 2D grid of nodes that you have used before it will work.