3ds Max 9 Bible

The Align commands are an easy way to automatically transform objects. You can use these commands to line up object centers or edges, align normals and highlights, align to views and grids, and even line up cameras.

Aligning objects

Any object that you can transform, you can align, including lights, cameras, and Space Warps. After selecting the object to be aligned, click the Align flyout button on the main toolbar or choose Tools Align (or press Alt+A). The cursor changes to the Align icon. Now, click a target object with which you want to align all the selected objects. Clicking the target object opens the Align Selection dialog box with the target object's name displayed in the dialog box's title, as shown in Figure 8.11.

Figure 8.11: The Align Selection dialog box can align objects along any axes by their Minimum, Center, Pivot, or Maximum points.

The Align Selection dialog box includes settings for the X, Y, and Z positions to line up the Minimum, Center, Pivot Point, or Maximum dimensions for the selected or target object's bounding box. As you change the settings in the dialog box, the objects reposition themselves, but the actual transformations don't take place until you click the Apply button or the OK button.

Using the Quick Align tool

The first flyout tool under the Align tool in the main toolbar (and in the Tools menu) is the Quick Align tool (Shift+A). This tool aligns the pivot points of the selected object with the object that you click on without opening a separate dialog box.

Aligning normals

You can use the Normal Align command to line up points of the surface of two objects. A Normal vector is a projected line that extends from the center of a polygon face exactly perpendicular to the surface. When two Normal vectors are aligned, the objects are perfectly adjacent to one another. If the two objects are spheres, then they touch at only one point.

To align normals, you need to first select the object to move (this is the source object). Then choose Tools Normal Align or click the Normal Align flyout button under the Align button on the main toolbar (or press Alt+N). The cursor changes to the Normal Align icon. Drag the cursor across the surface of the source object, and a blue arrow pointing out from the face center appears. Release the mouse when you've correctly pinpointed the position to align.

Next, click the target object, and drag the mouse to locate the target object's align point. This is displayed as a green arrow. When you release the mouse, the source object moves to align the two points and the Normal Align dialog box appears, as shown in Figure 8.12.

Figure 8.12: The Normal Align dialog box allows you to define offset values when aligning normals.

When the objects are aligned, the two points match up exactly. The Normal Align dialog box lets you specify offset values that you can use to keep a distance between the two objects. You can also specify an Angle Offset, which is used to deviate the parallelism of the normals. The Flip Normal option aligns the objects so that their selected normals point in the same direction.

Objects without any faces, like Point Helper objects and Space Warps, use a vector between the origin and the Z-axis for normal alignment.

Tutorial: Aligning a kissing couple

Aligning normals positions two faces directly opposite one another, so what better way to practice this tool than to align two faces?

To connect the kissing couple using the Normal Align command, follow these steps:

1. Open the  Kissing couple.max file from the Chap 08 directory on the DVD.

   This file includes two extruded shapes of a boy and a girl. The extruded shapes give us flat faces that are easy to align.

2. Select the girl shape, and choose the Tools Normal Align menu command (or press Alt+N). Then drag the cursor over the extruded shape until the blue vector points out from the front of the lips, as shown in Figure 8.13.

3. Then drag the cursor over the boy shape until the green vector points out from the front of the lips. Release the mouse, and the Normal Align dialog box appears. Enter a value of 5 in the Z-Axis Offset field, and click OK.

Figure 8.13 shows the resulting couple with normal aligned faces.

Figure 8.13: Using the Normal Align feature, you can align object faces.

Aligning to a view

The Align to View command provides an easy and quick way to reposition objects to one of the axes. To use this command, select an object and choose Tools Align to View. The Align to View dialog box appears, as shown in Figure 8.14. Changing the settings in this dialog box displays the results in the viewports. You can use the Flip command for altering the direction of the object points. If no object is selected, then the Align to View command cannot be used.

Figure 8.14: The Align to View dialog box is a quick way to line up objects with the axes.

The Align to View command is especially useful for fixing the orientation of objects when you create them in the wrong view. All alignments are completed relative to the object's Local Coordinate System. If several objects are selected, each object is reoriented according to its Local Coordinate System.