Polygon meshes facilitate extremely flexible modeling because they can be used to produce high-quality, smooth surfaces as well as low-resolution, fast-rendering surfaces. Games can use only a small amount of polygons per surface (called low-poly models) in order for game engines to render them on the fly. Thus, polygons are the surface type of choice for game and Internet developers. A proficient modeler can create a good- looking, fast-loading model by using just a few well-placed polygons (Figure 3.32).
Figure 3.32 A low-polygon model renders fast and can be developed quickly (this one is by Andrew Britt).
Polygons have many components, which you use to manipulate the final look of the surface. The components themselves are made up of faces, edges, and vertices (Figure 3.33)all of which combine to help define the shape of the polygonal object. Each of these components can be manipulated individually, giving the creator precise control of polygon construction.
Figure 3.33 Faces, edges, and vertices make up the polygon components.
You can create polygons, or polys for short, one at a time, slowly adding to the surface's resolution. Or you can start with a very simple poly object (for example, a poly primitive; see the next section), and use the Smooth command to add more individual polys, increasing the surface's resolution and smoothness (Figure 3.34). To learn more about the Smooth command, see Chapter 8.
Figure 3.34 You can start with a simple poly object, like a poly primitive (left), and use the Smooth command to add more individual polys (right).
Subdivisions are an important part of a polygonal mesh. The number of subdivisions in the poly surface determines how smooth the final surface will render (Figure 3.35). Decreasing the number of subdivisions results in fewer faces, making the surface appear much more angular. You can set the number of poly subdivisions before or after you create an object. You can also subdivide individual polygons, giving you precise control over the final number of polygons.
Figure 3.35 The smoothness of the final surface is determined by the number of subdivisions in the poly surface. The default surface is on the left; subdivisions have been added on the right.
About Polygon Primitives
Polygon primitives, like NURBS primitives, represent a collection of frequently used predefined surfaces. These predefined primitive surfaces can save you time in creating objects and give you a head start on creating more detailed shapes.
Maya includes six polygon primitives: sphere, cube, cylinder, cone, plane, and torus (Figure 3.36). You can use polygon primitives to speed workflow because each face that describes the surface has already been drawn for you.
Figure 3.36 The polygon primitives (clockwise from left): cylinder, cube, sphere, cone, torus, and plane (center).
Once you've created polygon primitives, you can (among other things) extrude, split, subdivide, merge, bevel, and separate them. This allows for fast modeling of objects and precise control over the number of faces used for the surfacewhich means you can control the amount of render time needed to produce the final image (Figure 3.37).
Figure 3.37 Polygon primitives can be extruded, split, subdivided, merged, beveled, and separated (among other things). Here, a beveled primitive cube is shown.
Creating polygon primitives
Polygon primitives are found in the Create menu within the Polygon Primitives submenu. You can access polygon primitives via the Hotbox, as described below. By clicking their icons in the Polygons Shelf, you can quickly create any of the poly primitives.
When you create a poly primitive, Maya places the center point of the object at the origin of the scene (just as it does when you create a NURBS primitive).
You can create poly primitives by following the steps outlined below.
To create a polygon primitive using the main menu:
From the Create menu select the Polygon Primitives submenu.
Select the name of the primitive you want to create (the torus is shown here) (Figure 3.38).
Figure 3.38 You can create a polygon primitive by choosing Create > Polygon Primitives. Here the torus primitive is selected.
A polygon primitive is created at the origin (0, 0, 0) of the Maya scene (Figure 3.39).
Figure 3.39 A polygon primitive appears at the origin of the Maya scene; the torus is shown.
The Hotbox is a great time-saver because it allows you to select objects and primitives without returning to the main menu. You can display the Hotbox from anywhere in the Maya window, making access to the Maya menus even faster.
To create a polygon primitive using the Hotbox:
Hold down Spacebar anywhere in the scene to display the Hotbox.
From the Create menu in the Hotbox select the Polygon Primitives submenu (Figure 3.40).
Figure 3.40 You can access the Polygon Primitives submenu via the Hotbox.
Select the name of the primitive you want to create (the cone is shown here) (Figure 3.41).
Figure 3.41 Select the name of the primitive you want to create.
A polygon primitive is created at the origin of the Maya scene (Figure 3.42).
Figure 3.42 A polygon primitive appears at the origin of the Maya scene.
The default Shelf in Maya holds shortcut icons for the cube and cylinder polygon primitives (Figure 3.43). Selecting these primitives from the Shelf can save the two or three steps you would take to select the primitive from the Create menu.
Figure 3.43 Shortcut icons for the polygon primitives in the Polygons Shelf.
To create a polygon primitive using the Shelf:
Appendix From the Polygons Shelf, select the icon of the polygon primitive you would like to createfor example, the cube or cylinder .
The primitive is created at the origin of the Maya scene (Figure 3.44).
Figure 3.44 The primitive appears at the origin of the Maya scene (the cube is shown).
If the Shelf is not already open, open it by going to the Display menu and selecting UI Elements > Shelf.
To add primitives or other objects to the Shelf, hold down Shift and Ctrl/Control while selecting the primitive in the Create menu.