3ds Max 2012 Bible - Kelly L. Murdock [324]
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.
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, Merge, Attach, and Insert. 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 27.24 shows the original object and the first four possible Boolean operators.
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. •
FIGURE 27.24
Object before any operations and with Boolean operations: Union, Intersection, Subtraction, and Merge with the Imprint option enabled
The Attach operation combines the objects like Union but keeps them as separate elements of the same compound object. For example, if you were to look inside a compound object created with Union, you would not see the interior polygons of the combined object, but with Attach, the interior polygons would still be there.
The Insert operation subtracts the second object from the first and then combines the two objects into one. If the subtracted volume makes a dent or hole into the first object, then that hole remains after the two are combined, but if the second surface has access to the first object through a hole, then the first surface covers the subtracted volume. In Figure 27.25, two tube objects have been overlapped with a box object. The left tube is capped at the bottom, forming a closed volume, but the right tube is open at the bottom. When made into a ProBoolean object with the Insert operations, the closed volume is subtracted, but the open volume is not.
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.
FIGURE 27.25
The Insert operation only maintains closed volumes when subtracted.
Cross-Reference
You also can apply Boolean operations to shapes using the Boolean operators available for Editable Meshes in the Geometry rollout. Chapter 12, “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