critical analysis of the absence of interior - Bilkent University

3D objects include ‘planes’, ‘volumes’, ‘quadric surfaces’ and ‘3D symbols’ as
Szalapaj (2001) mentioned (Figure 3.2). To begin with, ‘planes’ are defined with
three non-collinear points that are flat and are constructed simply by creating a 2D
form and extruding this form. Next, ‘volumes’ are drawn by providing parameters
like length, width, height, radius to predetermined 3D volumes existing in most of
the CAAD software. Some of the examples of ‘volumes’ include; blocks, spheres,
hemispheres, cones and cylinders. ‘Quadric surfaces’ are generated from conic
sections which are the 2D shapes formed when a plane cuts a cone at various angles.
Later on, these sections are rotated 180 degree through an axis while generating a
surface. Spheres, ellipsoids, hyperboloids and paraboloids are some of examples of
these 3D objects (Szalapaj, 2001). Finally, ‘3D symbols’ are similar to 2D symbols
and mostly created by users. While these symbols reduce the memory size of the
models, each symbol can also carry additional information about their cost, size, etc
(Szalapaj, 2001).
Figure 3.2 3D CAAD objects
30