Several methods are available for the user to create components using our 3D Solid Modeler. A user can explicitly create individual parts by utilizing the Boolean operators (Union, Subtraction, or Intersection) on two or more components, or on a component and a slicing plane. Another method would be to simply allow the automatic Boolean operations to perform implicit boolean operations, using the Rules of Precedence based on certain component characteristics (i.e., hierarchy and intersection). The implicit booleans are especially useful for modeling the air region around the other components. Or, one can use the preferred practice of combining the two methods to get the desired geometric result.

Implicit use

To utilize the implicit Boolean operators, the user needs to understand how hierarchy, and the rules of precedence can be used to shape the geometry of components in the solid model. In the example that follows, three components are created that help demonstrate the aforementioned features. Combined with viewing the Initial 3D Mesh and the hiding and reordering of components, this example shows the effects of Boolean operations and the rules of precedence on the visible components.

Rules of Precedence

Infolytica's 3D Solid Modeler automatically performs Boolean operations on fully and partially intersecting components, based on the following:

1. For fully intersecting components, the space of the smaller component prevails over the larger one.
2. A component's space has precedence over all other partially intersecting components that precede it in the model's family tree. (i.e., If you have three partially intersecting components, the second component in order prevails over the first but the third component prevails over both the first and the second.)

The user can control how intersecting components are meshed by reordering of components in the object tree.

Component Properties

	Component #1	Component #2	Component #3
Name	Large box	Small box	Cylinder
Coordinates	(0,0; 5,0; 5,5; 0,5; 0,0)	(1,1; 4,1; 4,4; 1,4; 1,1)	(0,0; 0,3)
Distance	10	10	10
Material	Aluminum 6061	Carpenter: Silicon Steel	Copper: 5.77e7 Siemens/meter

Note: For the purpose of this example, the distance and material chosen are used only to represent depth and color.

Effects of Boolean operations and the rules of precedence

Some characteristics worth noting, in the context of Solid Modeling, about the three components that have been created:

Large box: Fully intersected by the Small box component and is partially intersected by the Cylinder component.

Small box: Fully intersects the Large box component and is partially intersected by the Cylinder component.

Cylinder:  Partially intersects both the Large box and Small box components and is the last component built.

Hide the Small Box component and view initial 3D mesh of the model

This procedure shows the effect of Rule #1 over the Large box and Small box components.

From the Object page, we select Small box, and make it invisible. An X appears next to the component to signify that it is hidden.

Hide the Cylinder component and view initial 3D mesh of the model

This procedure shows the effect of Rule #2 over the Large box and Small box components.

Firstly, from the Object page, we select Small box, and then make it visible. A check mark appears next to the component to signify that it is visible.

Secondly, from the Object page, we select Cylinder, and then make it invisible. An X appears next to the component to signify that it is hidden.

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Hide the Large box component, reorder the components, and then view initial 3D mesh of the model

This procedure shows the effect of Rules #1 and #2 over the Cylinder and Small box components after the Large box component has been moved, in essence making Large box the last component in the family tree.

Important: Since the Small box's space still prevails over the Large box (rule #1), the effect of being partially intersected by the cylinder component (rules #1 and #2) does not apply, given that Large box now prevails over the partially intersecting region it shares with Cylinder (rule #2).

i.e., if Small box prevails over Large box (rule #1) and Large box prevails over Cylinder (rule #2), then Small box prevails over Cylinder (rules #1 and #2).

Firstly, from the Object page, we select Cylinder, and then make it visible. A check mark appears next to the component to signify that it is visible.

Secondly, from the Object page, we select Large box, make it invisible, and then drag-and-drop it over Cylinder, essentially making it the last component in the model hierarchy. An X appears next to the component to signify that it is hidden.