makeboundingbox explicitly constructs a 3D bounding box from a set of
6 numbers defining the opposite corners of a cube. Most of the time as an end
user you will want to compute/get the bounding box of objects/vertices using
makeboundingbox(x, dims, input = c("boundingbox", "bounds"))
A vector or matrix specifying a bounding box
The number of voxels in each dimension when x is a BoundingBox matrix.