and the members 40 need not be straight or extend the entire length of the apparatus 10 further the members 40 can be positioned within the shaper 14 i e between the sheet 50 and the roller 12 so that the members 40 can be actuated outward toward the sheet 50 and shaper 14 fig8 and 9 illustrate an alternative forming apparatus 110 in which a shaper 114 similar to the shaper 14 described above is supported on a plurality of support members 140 that are supported by a frame 116 the support members 140 can be longitudinal members such as rods or other shapes that are arranged in a generally parallel configuration as shown in fig8 so that the members 140 define spaces 142 therebetween in other embodiments the support members 140 can be arranged in other configurations in which the support members 140 need not be parallel a heater 122 can be provided within each member 140 or elsewhere in the apparatus 110 and the apparatus 110 can be partially or completely enclosed by an insulative shroud 118 the thermoplastic sheet 50 is disposed on a first side of the shaper 114 and a second side of the shaper 114 is disposed against the members 140 so that the shaper 114 extends.