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4.4.1 Intersect
4.4.2 Subtract
4.4.3 Unite
2021.11

4.4 Geometry Booleans

Cubit supports boolean operations of intersect, subtract, and unite for bodies.

An automatic function associated with webcutting operations is regularizing geometry which can be turned off or back on with the following command:

Set Boolean Regularize [ON | off]

4.4.1 Intersect

The intersect command generates one or more new volumes composed of the space that is shared by the volumes being intersected. There are two forms of the command. The first form is:

Intersect {Volume|[Body]} <range> [Keep] [Preview]

In this form, all volumes in the range will be intersected, and the resulting intersection volume(s) will contain all intersections of all input volumes. The original volumes will be deleted. The second form is:

Intersect {Volume|[Body]} <id> [With {Volume|[Body]} <range>] [Keep] [Preview]

In this form, the first volume is intersected with all volumes in the range specified using the with keyword. The original volume will be deleted and the other volumes updated with the intersection results.

The keep option results in the original volumes used in the intersect being kept.

If the preview option is included in the command, the input volumes will not be modified. The computed intersection volume will be drawn as a red, shaded solid. For best results change the graphics mode to transparent or hidden line so the intersection is visible. Otherwise the intersection volume will be hidden by the volumes being intersected.

4.4.2 Subtract

The subtract operation subtracts one body or set of bodies from another body or set of bodies. The order of subtraction is significant - the body or bodies specified before the from keyword is/are subtracted from bodies specified after from. The new body retains the original body’s id. If any additional bodies are created, they will be given the next highest available ids. The keep option simply retains all of the original bodies. The command is:

Subtract [Volume|BODY] <range> From [Volume|BODY] <range> [Imprint] [Keep]

The imprint option imprints the subtracted bodies onto the resultant body.

4.4.2.1 Remove Overlap

The remove overlap command is a simplified form of the subtract operation above. This command takes exactly two volumes as arguments and uses the modify argument to define the volume where material is to be removed.

remove overlap volume <id1> <id2> modify [volume <id> | smaller | larger]

The smaller and larger options are an alternate method of specifying which volume from <id1> or <id2> where material will be removed. When these argument are used, the geometric volume is measured for both volumes and the smaller or larger volume repectively is used as the modify entity. When both volumes have exactly the same volume, the smaller or larger entity ID is used

4.4.3 Unite

The unite operation combines two or more bodies into a single body.

The keep option preserves the original bodies and the new body created is given the next highest body ID available.

The include_mesh option creates a new meshed body from the original meshed bodies. For this function to work properly, the original bodies must be merged.

Unite [Volume|BODY] <range> [With [Volume|BODY] <range>] [include_mesh] [Keep]

Unite Body {<range> | All} [Keep]

The second form of the command unites multiple bodies in a single operation. If the all option is used, all bodies in the model are united into a single body. If the bodies that are united do not overlap or touch, the two bodies are combined into a single body with multiple volumes.

The unite command allows sheet bodies to be united with solid bodies. To disable this capability you can turn the following setting off:

Set Unite Mixed {ON|Off}