Molten Glassblowing Simulator (2D)

This 2D side-view simulator models a gob of molten glass on the end of a blowpipe as it is inflated into a bubble. Glass viscosity drops exponentially with temperature, so raising the furnace reheat rate keeps the gob soft enough to shape, while blowing pressure has to overcome the glass's surface tension — strongest when the bubble is still small — to expand it. As the bubble grows, conservation of glass volume in the wall means it must get thinner, and constant radiative cooling steadily raises viscosity again until the piece stiffens and holds its shape.