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Modeling Helpers

In the Create panel (and the Create menu) is a category of miscellaneous objects called Helpers (the icon looks like a tape measure). These objects are useful in positioning objects and measuring dimensions. The buttons in the Helper category include Dummy, Grid, Point, Tape, Protractor, and Compass.

Using Dummy and Point objects

The Dummy object is a useful object for controlling complex object hierarchies. A Dummy object appears in the viewports as a simple cube with a pivot point at its center, but the object will not be rendered and has no parameters. It is used only as an object about which to transform objects. For example, you could create a Dummy object that the camera could follow through an animation sequence. Dummy objects are used in many examples throughout the remainder of the book.

The Point object is very similar to the Dummy object in that it also is not rendered and has minimal parameters. A Point object defines a point in space and is identified as an X, as an Axis Tripod, or as a simple Box. The Center Marker option places an X at the center of the Point object (so X really does mark the spot). The Axis Tripod option displays the X, Y, and Z axes, and the Box option displays the Point object as a Box. The Size value determines how big the Point object is. The Constant Screen Size option keeps the size of the Point object constant, regardless of how much you zoom in or out of the scene. The Draw on Top option draws the Point object above all other scene objects, making it easy to locate. The main purpose for the Point object is to mark positions within the scene.

Caution	Point objects are difficult to see and easy to lose. If you use a point object, but sure to name
	it so you can find it easily in the Select by Name dialog box.

Measuring coordinate distances

The Helpers category also includes several handy utilities for measuring dimensions and directions. These are the Tape, Protractor, and Compass objects. The units are all based on the current selected system units.

Using the Measure Distance tool

In the Tools menu is a command to Measure Distance. This tool works easily. Just select it, click at the starting point and again at the ending point, and the distance between the two clicks is shown in the Status Bar at the bottom of the interface. Measure Distance also reports the Delta values in the X, Y, and Z directions. You can use this tool with the Snap feature enabled for accurate measurements.

Using the Tape helper

You use the Tape object to measure distances. To use it, simply drag the distance that you would like to measure and view the resulting dimension in the Parameters rollout. You can also set the length of the Tape object using the Specify Length option. You can move and reposition the endpoints of the Tape object with the Select and Move button, but the Rotate and Scale buttons have no effect.

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Using the Protractor helper

The Protractor object works in a manner similar to the Tape object, but it measures the angle between two objects. To use the Protractor object, click in a viewport to position the Protractor object. (The Protractor object looks like two pyramids aligned point to point and represents the origin of the angle.) Then click the Pick Object 1 button, and select an object in the scene. A line is drawn from the Protractor object to the selected object. Next, click the Pick Object 2 button. The angle-formed objects and the Protractor object are displayed in the Parameters rollout. The value changes as either of the selected objects or the Protractor is moved.

Note All measurement values are presented in gray fields within the Parameters rollout. This gray field indicates that the value cannot be modified.

Using the Compass helper

The Compass object identifies North, East, West, and South positions on a planar star-shaped object.

Cross-	The Grid helper object is discussed along with grids in Chapter 10, “Transforming Objects —
Reference	Translate, Rotate, and Scale.” Compass object is mainly used in conjunction with the Sunlight
	System, which you can learn about in Chapter 27, “Basic Lighting Techniques.”

Using the Measure utility

In the Utilities panel is another useful tool for getting the scoop on the current selected object: the Measure utility. You can open the Measure utility as a floater dialog box, shown in Figure 12-9. This dialog box displays the object’s name along with its Surface Area, Volume, Center of Mass, Length (for shapes), and Dimensions. It also includes an option to Lock the current Selection.

Figure 12-9: The Measure utility dialog box displays some useful information.

Tutorial: Testing the Pythagorean Theorem

I always trusted my teachers in school to tell me the truth, but maybe they were just making it all up, especially my math teacher. (He did have shifty eyes, after all.) For my peace of mind, I want to test one of the mathematical principles he taught us, the Pythagorean Theorem. (What kind of name is that anyway?)

If I remember the theorem correctly, it says that the sum of the squares of the sides of a right triangle equals the hypotenuse squared. So, according to my calculations, a right triangle

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with a side of 3 and a side of 4 would have a hypotenuse of 5. Because Max is proficient at drawing shapes such as this one, we test the theorem by creating a box with a width of 40 and a height of 30 and then measuring the diagonal.

To test the Pythagorean Theorem, follow these steps:

1.Select the Create Standard Primitives Box menu command, and drag and click in the Top view to create a Box object. Change its parameters to 40 for the Length, 30 for the Width, and 10 for the Height values. Then right-click in the active viewport to exit Box creation mode, and press the Z key to zoom in on the Box object.

2.Right-click any of the Snap buttons on the main toolbar to open the Snap and Grid Settings dialog box, select the Snaps panel, and set the Snap feature to snap to vertices by selecting the Vertex option. Close the Grid and Snap Settings dialog box, and enable the 3D Snap feature by clicking on the Snap button in the main toolbar (or by pressing S).

3.Select the Create Helper Tape menu command.

4.In the Top viewport, move the cursor over the upper-left corner of the object, and click on the blue vertex that appears. Then drag down to the lower-right corner, and click the next blue vertex that appears. Note the measurement in the Parameters rollout.

Well, I guess my math teacher didn’t lie about this theorem, but I wonder whether he was correct about all those multiplication tables. Figure 12-10 shows the resulting box and measurement value.

Figure 12-10: I guess old Pythagoras was right. (Good thing I have Max to help me check.)

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Summary

Understanding the basics of modeling helps you as you build scenes. In this chapter, you’ve seen several different object types that are available in Max. Many of these types have similar features such as Soft Selection. Several helper objects can assist as well. This chapter covered the following topics:

Understanding parametric objects and the various modeling types

Using subobjects and soft selections

Using Helper objects

Now that you have the basics covered, you’re ready to dive into the various modeling types. The first modeling type on the list is splines and shapes, which is covered in the next chapter.