Extrusion

   

  object new_extrusion(char *filename, int stop_at_first);

Extrusions are used to create a solid from a 2 dimensional shape. The shape is input as a pgm, ppm or pbm greyscale image file. The background of the shape should be black and the shape should be white.

The extrusion is created in the unit cube from 0 to 1 in X, Y and Z. The 2 dimensional shape is on the face z = 1 and its reflection on the face z = 0;

The second parameter passed is stop (see the heightfield definition).

 
Figure 30: The Extrusion Primitive

  the_object = new_extrusion("y.pgm",TRUE);
  the_object->material = ltblue; 
  LINK(the_scene, PLUS, the_object);