Working with ProBoolean and ProCutter Objects

The original Boolean compound object worked well enough for combining, subtracting, and intersecting objects, but it had some limitations that have been overcome with the ProBoolean and ProCutter compound objects. The original Boolean could combine only two operands together, but the ProBoolean object can perform multiple Boolean operations simultaneously. ProBoolean also can subdivide the result into quad faces. The results of the ProBoolean and ProCutter objects are much cleaner and more accurate than the original Boolean object.

The original Boolean compound object still is available for backward compatibility, but if you perform a new Boolean operation, you really should use the ProBoolean object.

NEW FEATURE 

The ProBoolean and ProCutter compound objects are both new to 3ds Max 9.

Using ProBoolean

When two objects overlap, you can perform different Boolean operations on them to create a unique object. The ProBoolean operations include Union, Intersection, Subtraction, and Merge. Two additional options are available: Imprint and Cookie.

The Union operation combines two objects into one. The Intersection operation retains only the overlapping sections of two objects. The Subtraction operation subtracts the overlapping portions of one object from another. The Merge operation combines objects without removing the interior faces and adds new edges where the objects overlap. Figure 18.24 shows the original objects and each of the possible Boolean operators.

Figure 18.24: Object before any operations and Boolean operations: Union, Intersection, Subtraction, and Merge with the Imprint option enabled

Note 

Unlike many CAD packages that deal with solid objects, Max's Booleans are applied to surfaces, so if the surfaces of the two objects don't overlap, all Boolean operations (except for Union) will have no effect.

The Cookie option causes the operation to cut the original object without adding any of the faces from the picked object to the original object. The Imprint option causes the outline of the operation to appear on the original object.

All Boolean operations are added in the order in which they are applied to a list in the Parameters rollout. You can select any of the operations in the list at any time and change the operation. For example, if you select the Subtraction operation from the list and then change the operation type to Union and click the Change Operation button, the Subtraction changes to a Union. With an operation selected in the list, the Extract Selected button restores the original object. When using this button, you can choose to Remove, Copy, or Instance the operation.

The order in which the operations are applied affects the result. You can reorder the operations in the list by selecting an operation, choosing its position in the list, and clicking the Reorder Ops button.

CROSS-REF 

You also can apply Boolean operations to shapes using the Boolean operators available for Editable Meshes in the Geometry rollout. Chapter 14, "Drawing and Editing 2D Splines and Shapes," covers these 2D Boolean operators.

The materials that get applied to a ProBoolean result can be set to use the Operand Material or to retain the Original Material. If you use the Operand Material with the subtraction operation, then the surface that touches the picked object retains the removed object's material and the rest of the object has the original object's material. If the Retain Original Material option is selected, then the entire result gets the original object's material.

In the Advanced Options rollout are options for updating the scene and for reducing the complexity of the object. The Decimation value is the percentage of edges to remove from the result. If you plan on smoothing the object or converting it to an Editable Poly object, then you want to enable the Make Quadrilaterals option, which causes the polygon reduction to avoid triangles in favor of quads. You also can set the Quad Size, and you can select how planar edges are handled.

Tutorial: Creating a keyhole

What was it that Alice saw when she looked through the keyhole? The ProBoolean feature is the perfect tool for cutting a keyhole through a doorknob plate.

To use the ProBoolean object to create a keyhole, follow these steps:

1. Open the  Doorknob.max file from the Chap 18 directory on the DVD.

2. Select the doorknob plate object positioned where the keyhole is, and choose the Create Compound ProBoolean menu command. In the Parameters rollout, select the Subtraction option.

3. In the Pick Boolean rollout, click the Start Picking button and select the Box and Cylinder objects positioned where the keyhole should be.

Figure 18.25 shows the finished keyhole.

Figure 18.25: A keyhole built using the ProBoolean object

Using ProCutter

The original Boolean compound object included a Cut option. This feature has been replaced with ProCutter that offers many more features than the original option. ProCutter allows you to cut a single object (known as the Stock object) with multiple cutter objects.

You can pick both the Stock and Cutter objects using the buttons found in the Cutter Picking Parameters rollout. You have four options with each selection: Reference, Move, Copy, or Instance. The Auto Extract Mode option automatically replaces the selected stock object with the extracted result. The Explode by Elements option works only when the Auto Extract Mode option is enabled. It separates each cut element into an object.

Within the Cutter Parameters rollout, you can select from three Cutting Options. The Stock Outside Cutter option keeps the portion of the stock object that is on the outside of the cutter. The Stock Inside Cutter option is the opposite, keeping the stock portion inside the cutters. The Cutters Outside Stock option maintains those portions of the cutters that are outside of the stock.

All selected cutters and stock objects are added to a list in the Cutter Parameters. Using the Extract Selected button, you can restore any cutter or stock object that has been operated on as a Copy or Instance. Materials and Decimation also work the same as for ProBoolean objects.

Tip 

The ProCutter features are helpful for dividing an object that will be animated exploding into piece.

Tutorial: Creating a jigsaw puzzle

The ProCutter is useful for creating destructive scenes just as shattering glass to pieces and breaking down buildings, but it also can be used for constructive cutting such as creating a jigsaw puzzle.

To use the ProCutter compound object to divide an object into a jigsaw puzzle, follow these steps:

1. Open the  ProCutter puzzle.max file from the Chap 18 directory on the DVD. This file includes a simple box mapped with a scenic image and several extruded lines that mark the jigsaw puzzle's edges.

2. Select one of the extruded lines that mark where the cuts should be (known as a cutter), and choose the Create Compound ProCutter menu command.

3. In the Cutter Parameters rollout, enable the Stock Outside Cutter along with the Stock Inside Cutter options. Select the Retain Original Material option also.

4. In the Cutter Picking Parameters rollout, enable the Auto Extract Mesh and Explode By Elements options; then click the Pick Cutter Objects button and select two of the remaining cutter objects. Then select the Pick Stock Objects button and choose the Box object in the viewport.

5. Select the final cutter and repeat steps 2 and 3. Enable the Auto Extract Mesh and Explode By Elements options. Then click the Pick Stock Objects button and select the three objects that haven't been cut to complete the cuts.

6. Open the Material Editor and drag the image material onto each puzzle piece.

Figure 18.26 shows the final puzzle with one piece moved away from the others.

Figure 18.26: A puzzle cut using the ProCutter compound object