Is it necessary with binary encoding in genetic algorithms?

I'm doing a project exploring the use of genetic algorithms in architecture, where we use an evolutionary approach for creating Voronoi tessellation in 3d. This is done using ofxVoro++ for openFrameworks (c++).

Our chromosomes for the Genomes is a vector (list) of points in 3D. We have implemented single- and two-point crossover and a mutation, which randomises these points with a certain probability. In most examples I've seen, the genome is encoded binarily, which I presume would cause mutation and crossover to act differently.

So my question is this: Are there any other benefits to binary encoding (except speed) and how would you handle such an encoding/decoding in c++? Going from binary to a list of 3d-points.

Best regards, Fred