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Introduction
A primitive is an object that always keeps its primary form. For instance, although you can transform a cube using the rotate, size, x-y-z size, squash, or skew functions, the cube will keep its main characteristics: it consists of six planes and twelve ribs. However, not only can a free form be transformed using the functions of the transform menu, it can also be deformed, which allows you to shape it into almost any form you wish.
GIG supports three kinds of free forms: the free form rotation, the free form extrusion, and the free form patch. A free form rotation can be used for objects with rounded forms, such as glasses, bottles, etc. ff rotation always ensures a perfect balance by rotating around the fixed y axis. With free form extrusion it is easy to construct a flat object. A free form patch can be used for all kinds of forms, ranging from a mountainous landscape to a tube of toothpaste.
Changing the form of a ff rotation or extrusion can be done by moving or rotating points in a so-called path, by adding one or more points to the path, or by inserting or deleting one or more points. The free form patch can be changed by either transforming the points in a path or the points or paths in a net, or by inserting or deleting points or paths. Points, paths, and nets constitute a hierarchy: two or more points will form a path and two or more paths a net. Keep in mind that ff rotation and free form extrusion operate on points and paths; only free form patch operates on nets.
Free forms may be added to a modelling environment made up of primitives or free forms. However, if you want to modify a free form, you will have to use the free form menus: ff mode, ff trans, ff edit, and ff grids (ff is short for free form). If you want to work with those menus, you will have to activate the free form object independently of the environment primitives (e.g., with get solid tag).
Window configuration:
Quite different from what was stated about the windows for primitive modelling, the free form windows typically have another window setting. First of all, the working window is the upper left window, not the upper right one. The latter is called the ff mode window; it shows the wire-framed result of the ff actions in the working window. The default setting of the ff mode window is ff front. By clicking once in this window, the setting is changed to ff side, and by clicking twice to ff top. Clicking for the third time restores the default setting.
The lower right window, the solid mode window, displays a solid representation of the free form. The default setting of the solid mode window is solid cam 2. By clicking once in this window, the setting is changed to solid cam 1, and by clicking twice, to solid cam 3. Clicking for the third time restores the default setting.
Remember that the upper left window is always the active one.
