These functions were designed to be used in conjunction with the gtb-text tool.
The gtb-thicken function creates a rectangle that is centered around each line
(polygons based on two points) of a letter while the gtb-bubtext function creates a
cylinder that is centered on each line and caps the cylinder with a sphere at each
end. Both of these functions are designed to increase the readability of text in the
3D environment. These functions will also work for files that are not explicitly
text. The gtb-bubtext and gtb-thicken functions are designed to filter a GTB file
for any lines and extrude them in two or three dimensions respectively.