Using The Geometric Range Selection Mode

This section describes how to specify a threshold using a geometric range.

To activate the Geometric Range threshold:

Select the Geometric Range option from the Select Threshold drop-down menu.

The mode has four selection options available from the Select drop-down menu.

The defaults for each selection option use the global laboratory coordinate system. To change the coordinate system:

Use the drop-down menu that is labeled Coordinate System.

All properties that require specification of a point in 3-dimensional space are updated according to the chosen coordinate system. The tool accepts any available length unit, with different unit systems permitted in each field.

Min-Point, Max-Point

The Min-Point, Max-Point option specifies selection using minimum and maximum bounds, for each coordinate direction.

For linear values (X, Y, Z, and R), the order in which you specify the minimum and maximum bounds is not important. That is, a range from 10 mm to 2 mm selects the same entities as a range from 2 mm to 10 mm. For angular values ( $θ$ and $φ$ ) in cylindrical or spherical coordinate systems, the order of specification is important. The tool uses the right-hand rule to determine angular values in the positive rotation direction, relative to the axis of rotation. A range from 0 deg to 90 deg gives a different selection than a range from 90 deg to 0 deg. To illustrate, consider the following examples, which select faces in a cylindrical coordinate system:

A range in $θ$ from 0 deg (minimum) to 90 deg (maximum) results in the following selection:
A range in $θ$ from 90 deg (minimum) to 0 deg (maximum) results in a 270-deg selection:

The following table lists the valid range of values for angular coordinates:


System Type	Coordinate Direction	Valid Range
Cylindrical	$θ$	$- 2 π \leq θ \leq 2 π$
Spherical	$θ$	$0 \leq θ \leq π$
Spherical	$φ$	$- 2 π \leq φ \leq 2 π$

The minimum and maximum bounds have precise tolerances. If a vertex is marginally out of the geometric range, the selection does not include the associated faces and edges. You can overcome this issue in one of three ways:

Specify a slightly larger range, for example, -5 deg to 90 deg, instead of 0 deg to 90 deg.
This workaround is not possible for $θ$ in a spherical coordinate system, due to the valid range limits identified above.
Modify the local coordinate system in a manner that allows the range to include the required entities.
Use the Project Vertices tool to modify the location of vertices with respect to the chosen coordinate system.

Sphere Around Point

The Sphere around Point option selects entities that are included within a spherical threshold, which is defined by a point and radius.

Activating the Include partially contained option selects entities if any part of the entity is within the spherical threshold. If this option is deactivated, to tool only selects entities that are contained within the threshold.
The Point property specifies the centerpoint of the spherical threshold. The Radius specifies the radius, and hence extent of the spherical threshold.

Provided below is an example of the spherical threshold selection option. The transparent sphere does not appear in the Graphics window; it has been added for illustrative purposes.

Box Around Point

The Box around Point option selects entities that are included within a box threshold, which is defined by a point and half-distance.

Activating the Include partially contained option selects entities if any part of the entity is within the box threshold. If this option is deactivated, the tool only selects entities that are contained within the threshold.

The Point property specifies the centerpoint of the box threshold. The Half-distance specifies the extent of the threshold in each cartesian direction (x, y, and z), from the centerpoint. Therefore, a cube is always used as the threshold is defined by the same distance in all directions.

Provided below is an example of the box threshold selection option. The transparent box does not appear in the Graphics window; it has been added for illustrative purposes.

Closest N Faces

The Closest N faces option selects the closest user-defined amount of faces to a specified point. To determine the closest faces, the code first determines the closest point on each face to the user-defined point and finds the distance between these points.

The Closest N faces are then identified as the first N faces with the shortest distance.

The Point property specifies the reference of the threshold. The N property specifies the number of selected faces closest to the specified point.
Provided below is an example of the Closest N faces selection option. This example shows the closest 25 faces to the user-defined reference point. The sphere representing the point does not appear in the Graphics window; it has been added for illustrative purposes.