This chapter introduces you to polygonal primitive objects and shows you how to create polygonal text.

There are several ways to use primitives to build objects quickly and easily. Use primitives as a starting point, then use a combination of polygon creation and editing operations to complete a task. Throughout this book you'll find examples where primitives are used as the base element of a particular task in combination with many of the Maya editing and creation operations.

Topics include:

• "Basic polygonal primitive objects" on page 106.
• "Setting primitive options" on page 107.
• "Creating and editing text" on page 117.

The most basic object type is the primitive. Primitives are pure shapes that can be used as the basis of creating more complex models. There are six polygonal primitive objects-Sphere, Cone, Cylinder, Cube, Plane, and Torus.

You can instantly make simple objects like spheres, cubes, cylinders, cones, planes, and toruses. When you select the polygon primitive from the menu, it displays in all views at the origin of the grid (or ground plane).

To create a primitive with the default option settings, select
Create > Polygon Primitives and choose the primitive you want to create from the menu. If you are not satisfied with the results, you can always edit the primitive from the Channel Box or its Attribute Editor.

Most of the options for polygonal primitives are the same, therefore all options are described for all polygonal primitives in the following sections:

• "Specifying a primitive's radius" on page 108.
• "Specifying a primitive's subdivisions" on page 110.
• "Specifying a primitive's width and height" on page 113.
• "Changing a primitive's orientation" on page 113.
• "Preparing a primitive for texture mapping" on page 113.

If there are special options that do not apply to every primitive, they will be discussed separately.

To set primitive options:

1

Click the box () beside the type of primitive you want to create to open the options window (for example, Create > Polygon Primitives > Sphere-).

2

Change the option settings and press the Create button to create the primitive.

By default, the primitive displays centered at the world coordinate system. You can move it to any location using Maya's Move tool.

The Radius value specifies the distance from the center of the primitive in all directions. Polygonal primitives that have this option include Spheres, Cylinders, Cones, and Toruses.

Adjusting the Radius for these primitives is like changing the width for primitives that do not have circumference (like primitive planes and cubes).

Type a value or use the slider bar to specify the primitive's radius. You can also change these values in the Channel Box or Attribute Editor after you create the primitive.

The following examples show the difference between a Radius value of 1.0 (the default) and what happens when you change this value to 2.0.

Using the Section Radius option for a primitive Torus

The Section Radius option value specifies the size of the sections that make up a Torus. Change this value to increase or decrease the radius of these sections.

Using the Twist option for a primitive Torus

The Twist option value specifies the twist angle of the torus. Change this value to adjust the distance around the Torus in all directions.

The values you enter in these boxes change the primitive by adding or taking away faces of the polygon.

For primitives without caps (or sides) you can only subdivide in the X and Y direction. These include Spheres, Planes, and Toruses.

For primitives with caps, you can subdivide in all three directions, X, Y and Z. These include Cones, Cubes and Cylinders.

Using the Subdivision around Axis (Subdivisions X) option

Axis is equivalent to the X direction. This option is also called Subdivisions X in the Channel Box and the Attribute Editor.

Increase or decrease this value to add or take away faces in the X direction.

Using the Subdivision along Height (Subdivisions Y) option

Height is equivalent to the Y direction. This option is also called Subdivisions Y in the Channel Box and the Attribute Editor. Increase or decrease this value to add or take away faces in the Y direction.

Using the Caps (Subdivisions Z) option

Caps means the tops, bottoms, or sides of polygonal primitives. These include Cones, Cylinders, and Cubes.

Caps is equivalent to the Z direction. This option is also called Subdivisions Z in the Channel Box and the Attribute Editor. Increase or decrease this value to add or take away faces in the Z direction.

Enter values or use the slider to specify the height or width of a primitive. For polygonal primitive Cones and Cylinders, the Radius value is like the Width of the primitive so only the Height option applies. For primitive Planes and Cubes, both Width and Height values can be adjusted.

For a primitive plane, the Width value increases or decreases the plane along the X axis while the Height value increases or decreases the plane along the Z axis.

Be default, a primitive is created along the Y axis. You can change a primitive's default orientation before you create it by selecting the X or Z Axis button.

You cannot change the orientation for a new primitive from the Channel Box, but you can enter values in the Axis boxes in the Attribute Editor.

By default, UV values are assigned for texture mapping. If you do not plan to map textures on a polygonal primitive, you can toggle the Texture option off in the options window. Texture is on by default.

Important note about UVs

It is important to make sure UVs are present on an object or you cannot see the mapped textures in the view. This can happen if you inadvertently create a primitive object with the Texture option turned off or set to None.

To correct the problem, select the faces of the primitive and use any of the following tools in the Edit Polygons > Texture menu to create UVs on objects that do not have UVs-Planar Mapping, Cylindrical Mapping, Spherical Mapping, Create UVs Based on Camera, Normalize UVs, Unitize UVs, and Best Plane Texturing.

You can then use the Texture View to view the created UVs. Select the object and use any of the UV creation or editing Texture menu items.

Texture mapping options for primitive Cubes and Cylinders

The options window for a polygonal Cube and Cylinder primitive includes a Texture pop-up menu where you can select an item to specify how you want the texture to cover the primitive when you assign it. This pop-up menu is also available from the Attribute Editor.

None

Selecting None is like toggling Texture off for polygonal primitive Spheres, Cones, or Toruses.

Normalize the whole object/object

The default setting maps the texture over each face of the primitive and normalizes it so that it covers the entire object.

Normalize each face separately/face

If you select this option, Maya maps the texture to each face separately.

Texture mapping options for primitive Planes

The options window for a polygonal Plane primitive includes a Texture pop-up menu where you can select an item to specify how you want the texture to behave when you transform the plane after it is created. This pop-up menu is also available from the Attribute Editor.

None

Selecting None is like toggling Texture off for polygonal primitive Spheres, Cones, or Toruses.

Stretch to fit object/Stretch to fit

This is the default setting. When you change the shape of the primitive plane by adjusting the options in the option window or by adjusting the Width and Height in the Channel Box, the texture stretches to fit within the plane's transformed shape.

The following shows a rock texture mapped to a plane whose Width has been changed to 3.

Preserve Aspect ratio/Preserve Aspect Ratio

If you select this option, when you change the Width of the primitive plane, the texture fits uniformly to the new dimensions of the object.

To edit a primitive after you create it, use the Attribute Editor.

The following is the Attribute Editor for a polygonal primitive Sphere. The Attribute Editor for a primitive includes the same options and attributes you find in its options window and the Channel Box.

To see these attributes, click the tab with the primitive's name. For example, click the polySphere tab for a polygonal Sphere primitive.

The Poly text type is created as polygons which you can manipulate as you would any other polygonal entity. When this text type is selected, a planar trim curve is created between the curve and tessellate nodes.

By default, Maya creates text as NURBS geometry. If you want to create polygonal text, when you select Create > Create Text, be sure to click the to open the Text Curves options window and set the Type option to Poly.

To create polygonal text:

Before you press the Create button:

1

Type the text you want to create in the Text box.

2

Change the default font settings if necessary.

3

Change the options settings (see "Polygonal text settings" on page 119 next for details).

4

Press the Create button to create the text.

To change the default font:

• If you are working on an IRIX machine, select the font that you want from the menu that appears.
• If you are working on an NT machine:

1

At the end of the Font box, press the down arrow and click the select button to display the Font window.

2

Select a font from the Font menu, a style from the Font style menu, and a font size from the Size menu, and adjust any other properties you want to change.

3

The type of font you select appears in the Sample box. Press OK when done to select the font and close the Font window.

When you create polygonal text, Maya provides options that you can set to display and create your text for subsequent polygonal-type editing.

Change any of these options before you create the text.

Polygon Type options

If you select Triangle (the default), 3-sided polygons are created.

If you select Quads, 4-sided polygons are created. The following example shows text using the default font.

The settings are as follows:

• Polygon text Type-Quads
• Tessellation Method-Count
• Count value-50

Creating a text string

Type the word or words you want to create in the text box, set the polygon settings, and press the Create button.

Two instances of the word display-a NURBS (or curve) based text string and a polygonal text string. The polygonal text string is highlighted.

Once you move and transform your polygonal text, you can first delete the history on the new text, and then delete the NURBS text if you want to.

• To delete the history of the polygonal text, select the text and choose Edit > Delete by Type > History.
• To delete the NURBS text, select it either in the 3D view or from the Hypergraph and press the Backspace key.

Selecting and transforming polygonal text strings

To select the polygonal text to translate, you can do one of two things:

• Transform the highlighted text string to suit your needs as soon as it appears.

or

• In component mode, select the faces of the text and transform them.

To transform polygonal text in object mode:

Using the first method, immediately select the text as soon as you create it and use Maya's Move and Scale tools to transform the text to suit your needs.

Note This approach has limitations, however. If you want to change the text using polygonal operations and tools, you will have to enter component mode anyway. If you use this method, you add an extra step.

To transform polygonal text in component mode:

1

Select Polygons from the Selection Mask menu on the Status Line. Maya changes the pick mode to Polygons mode and makes faces available to select.

2

Marquee-select the faces of the polygonal letters in the string and transform them to suit your needs.

At this point, you can use polygonal operations, such as Extrude, to enhance and define the look you want.

To extrude the polygonal text string:

1

Marquee-select the faces.

2

Select Polygons > Extrude then use the manipulator handles to perform the extrusion.

To color the text string:

To color the text, you can use the Apply Color operation.

You can follow these steps, but if you need more information about applying color, see "Applying colors per-vertex" on page 254 and "Apply Color operation" on page 256. This chapter (Chapter 17, "Coloring Polygons") also provides information about applying colors using Artisan.

1

Make sure you are in a shaded mode. For instance, select Smooth Shade All from the Panel's Shading menu.

2

Set the selection mask to All Objects and marquee-select the text string.

3

Click the Select by component type icon, then with the right mouse button, click the Points icon and toggle Poly Vertices on from the pull-down menu.

4

Marquee-select the vertices on the text string.

5

Select Display > Custom Polygons Display - to open the Custom Polygons Display window.

6

Toggle Color on, set the Color material Channel to None, then press the Apply button.

Your text should display in black.

7

Select Edit Polygons > Colors > Apply Color - to open the Polygon Apply Color options window.

8

Use the sliders to set the colors you want to apply, then press the Apply Color button.

Tessellation Methods

These options are the same ones you set when you convert NURBS geometry to polygonal geometry. See Chapter 9, "Converting NURBS to polygons" for details.

See Choosing a tessellation method starting on page 169 for specific information.

• "Standard fit" on page 169.
• "General" on page 171.
• "Count" on page 172.
• "Control Points" on page 173.