Ball

Another way to select geometric entities is to define an enclosing Ball () to select geometric entities that are completely or partially inside the ball. To add this node, right-click the Definitions node and choose Selections>Ball.

Geometric Entity Level

Select the Level for the geometric entities: Domain, Boundary, Edge, or Point.

If Boundary (for 2D and 3D models) or Edge is selected, also select the Group by continuous tangent check box to extend the selection to all adjacent faces or edges that have continuous tangents (an angle less than the value in the Angular tolerance field) at their junctions (to select all faces that make up a continuous sheet, for example).

When the Group by continuous tangent check box is selected, set the tolerance on the continuity condition in the Angular tolerance field as the maximum angle between two faces or edges that are considered as having continuous tangents (a value between 0 and 180 degrees; the default value is 5 degrees).

See Output Entities for details about how the behavior depends on the condition for which the selection considers the group of entities to be enclosed.

Input Entities

The Entities list defaults to All, which bases the selection on all entities of the selected type.

Select From selections to base the selection on other defined selections. Then, in the Selections list, add the selections for which you want to create a selection of geometric entities from those selections that are located within the ball, box, or cylinder that you define for the resulting selection. Click the Add button () to open an Add dialog box that contains selections of the chosen geometric entity level that appear earlier in the geometry sequence. Use the Move Up (), Move Down (), and Delete () buttons to organize the list.

Ball Center/Ball Radius

Position the center of the ball by entering the center position in the x, y, and (3D only) z fields (the unit is the length unit for the geometry). Enter the radius for the ball (disk in 2D) in the Radius field. The default is 0.

Output Entities

For the selections made under Input Entities, define the dimension of the ball and select the condition for the geometric entities to be selected. Choose an option from the Include entity if list: Entity intersects ball (the default), Entity inside ball, Some vertex inside ball, or All vertices inside ball.

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If Entity intersects ball is kept as the default, it includes all geometric entities that intersect the enclosing ball, that is, the selection includes all entities that are partially or completely inside the ball. If in addition the Group by continuous tangent check box is selected for a boundary or edge under the Geometric Entity Level section, all entities in each group are selected if any entity in the group intersects the ball.

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For Entity inside ball it includes all geometric entities that are completely inside the enclosing ball. If in addition the Group by continuous tangent check box is selected for a boundary or edge under the Geometric Entity Level section, the entities in each group are selected only if all entities in the group are completely inside the ball.

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For Some vertex inside ball it includes all geometric entities where at least some vertex is inside the enclosing ball. If in addition the Group by continuous tangent check box is selected for a boundary or edge under the Geometric Entity Level section, all entities in each group are selected if any entity in the group has at least some vertex inside the ball.

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For All vertices inside ball it includes all geometric entities where all vertices are inside the enclosing ball. If the Group by continuous tangent check box is selected for a boundary or edge under the Geometric Entity Level section, the entities in each group are selected only if all entities in the group have all vertices inside the ball. This selection might differ slightly compared to when selecting Entity inside ball if the geometric entity is outside the ball at some points between the vertices.

The Ball, Box, and Cylinder selections use the rendering mesh to determine which entities fit the selection condition. You can control the detail for the rendering in the Preferences dialog box (select Graphics and Plot Windows and then use the Detail list under Visualization).

• Creating Named Selections in the Geometry Sequence • Ball Selection (Geometry Sequences)