Yes it is quite a simple matter to make complex murriae. It just takes time and annealing of the segments before cutting to length and assembly.
The more accuratly shaped that your segments are, helps minimise any distortion to the final preform. Which is assembled as described by the previous reply. Then carefully melted together and drawn out to the final cane.
My constructs are about the size of a small cup and pull out to between five and eight feet of cane. These have to be again annealed prior to cutting up.
Any trapped air lines can cause the cuts to run, so it is essential to eliminate most of the trapped bubbles in the melting together of the segments.
I vacuum encase my segment constructs to totally eliminate trapped air.
Best of luck
Ray Ansin
http://glassbeads.co.nz