Modeling at the editable mesh level has some distinct advantages and some disadvantages. But first, you must understand that, in order to be working at this level to begin with (the editable mesh level), you must be working with a piece of geometry whose modifier stack has been completely collapsed. This is important, because working at this level of the geometry prevents you from going back and adjusting the parameters of any previously applied modifiers.

Creating Models with Compound Objects

Compound objects are special models that are made up of two or more existing models. The compound objects are found on the Create tab of the Command Panel.

Compound objects serve special purposes in the modeling tool bag of tricks. Besides the fact that they require more than one object to complete their task, the end results of compound objects are usually models that would be very difficult to create with standard mesh-editing tools. Table 4.4 lists the compound objects and their uses.

	TIP The space warp version of Conform is easier to use than the Conform compound object.

Understanding Compound Objects

The technical concept behind a compound object is, of course, the use of two or more pieces of geometry to create a new object. Beyond that, what are some of the possible uses of the models themselves? Let’s look at a couple of specific examples of using compound objects.

Compound Objects as Problem Solvers

Compound objects are problem solvers because, by their nature, the types of geometry that these tools create can often be used to solve tough modeling issues. For example, if you need geometry that has a very stretched, taut-skin look, you can use the Connect compound object to achieve the effect. Let’s take a look.

1.  Open the file Connect.max on the CD (it’s shown in Figure 4.8). You will see objects that you will use with the Connect compound object to span geometry between. Notice some of the characteristics of these models. They have “open” areas or deleted faces. In some way or another, these objects have holes in them.

FIGURE 4.8  Open objects to be Connected

2.  Select either object.

3.  Go to Create Ø Geometry Ø Compound Objects and click the Connect button.

4. Click the “Pick Shape” button.

5.  Click the other object.

You will see that new geometry has been created and spans the holes in each of the objects (as seen in Figure 4.9).

FIGURE 4.9  The new geometry of the connected objects

To experiment further, adjust the Tension and Segment settings to see how increasing or decreasing the complexity of the compound object’s settings controls its appearance.

Using this method has saved the time it would have taken to model a sinewy-looking piece of geometry. Additionally, you still have the ability to change the operands and even animate them at the sub-object level. (There’s more detail on Connect later in this chapter.)

Compound Objects as Time Savers

A good example of saving time with a compound object uses the ShapeMerge object.

In this example, we will be accomplishing two tasks at once. The first task, in our project, will be to model a door opening in the side of an airplane. The second task will be to model the door that goes in that opening. We can complete both of these tasks by using ShapeMerge.

1.  Open the file called fuselage.max from the CD. In this scene, we have two objects: a cylinder and a four-sided shape (see Figure 4.10).

2.  Select the fuselage object and go to Create Ø Geometry Ø Compound Objects Ø ShapeMerge.

3.  When the menu activates, choose the “Pick Operand” button. Although it may appear as though nothing happened, if you look closely at the fuselage object, you will see that the shape has been projected onto the geometry.

FIGURE 4.10  We’ll add doors to this fuselage.

4.  Choose “Face” from the sub-mesh output settings.

5.  Go to the Modify tab and add an Edit Mesh modifier.

6.  Go to the Polygon sub-object level and detach the door faces.

7.  Select the fuselage object and collapse it to an editable mesh.

8.  Select the door, go to the Polygon sub-object level, and bevel the polygons.
With those examples in mind, let’s take a closer look at compound objects

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