Bending a glass pane or bottle to a precise shape is not feasible without professional equipment.
Glass sheet bending process.
At fraunhofer iwm glass bending processes have been developed for forming sheet glass especially with application of local heating.
All you need is a flame.
Non isothermal processing of the glass with hot and cold areas within the glass sheet enables.
Using the new laser based glass bending process it is possible to achieve precisely defined and extremely small bend radii so that even laminated safety glass can be bent around a corner.
The process involves adhering two sheets of tempered glass in overlying relation and positioning a containment barrier such as vinyl sheets over the adhered.
These processes have several advantages compared to conventional bending processes.
However glass rods and tubing is easy to bend and frequently done by artists and people working in laboratories.