Retain Selections over Time

You can retain selections for any particle passing through the selection group so that they remain selected once they have exited the Selection Group. If you use Manual Selection, the selected particles or Geometries remain selected over time. If you use other selection options such as Grid Bin Group, Geometry Bin, and so on, the particles or Geometries are only selected by default if the center of the particle or Geometry is inside the Bin Group.

To retain selections over time:

  1. Select the Retain selections over time checkbox.
    Any particle passing through the selection group will remain selected once they have exited the selection group. In the following example, a geometry bin has been created, and, as the particles pass through the bin, they are highlighted in orange and remain colored once they have left the bin area.


    Once they move outside the bin they are automatically removed from the selection.
  2. For Contacts, select the Attribute, Query Type, and Component.
    The selection impacts all contacts or any combinations of specific particle-particle or particle-geometry contacts.
    Table 1. Queries - Contacts
    Attribute Query Type Component
    Angular velocity Average, maximum, minimum, or total Magnitude, X, Y, Z
    Compressive force Average, maximum, minimum, or total N/A
    Coordination number Average, maximum, minimum or total N/A
    Diameter Average, maximum, minimum, or total N/A
    Moment of inertia Average, maximum, minimum, or total Magnitude, X, Y, Z
    Kinetic Energy Average, maximum, minimum, or total Magnitude, X, Y, Z
    Mass Average, maximum, minimum, or total N/A
    Number of particles Total-over-time checkbox N/A
    Potential energy Average, maximum, minimum, or total N/A
    Residence time Average, maximum, minimum, or total N/A
    Rotational kinetic energy Average, maximum, minimum, or total N/A
    Torque Average, maximum, minimum, or total Magnitude, X, Y, Z
    Total energy N/A N/A
    Total force Average, maximum, minimum, or total Magnitude, X, Y, Z
    Velocity Average, maximum, minimum, or total Magnitude, X, Y, Z
    Voidage [1] Total N/A
    Volume Average, maximum, minimum, or total N/A
    Custom property Average, maximum, minimum, or total Depends on the number of elements
  3. For Geometry, select the Attribute, Query Type, and Component.
    The selection impacts all Geometry or a particular section (as specified in the Creator).
    Table 2. Queries - Geometry
    Attribute Query Type Component
    Compressive force Average, maximum, minimum, or total N/A
    Number of geometry elements N/A N/A
    Pressure Maximum, minimum, or total pressure N/A
    Total force Average, maximum, minimum, or total Magnitude, X, Y, Z
    Torque (element) Average, maximum, minimum, or total. Total is the sum of the individual element torque values Magnitude, X, Y, Z
    Velocity Average, maximum, minimum, or total Magnitude, X, Y, Z
    Custom property Average, maximum, minimum or total Depends on number of elements
  4. For Particles, select the Attribute, Query Type, and Component.
    The selection impacts all particles or a particular particle type (as specified in the Creator).
    Table 3. Queries - Particles
    Angular velocity Average, maximum, minimum, or total Magnitude, X, Y, Z
    Compressive force Average, maximum, minimum, or total N/A
    Coordination number Average, maximum, minimum or total N/A
    Diameter Average, maximum, minimum, or total N/A
    Moment of inertia Average, maximum, minimum, or total Magnitude, X, Y, Z
    Kinetic Energy Average, maximum, minimum, or total Magnitude, X, Y, Z
    Mass Average, maximum, minimum, or total N/A
    Number of particles Total-over-time checkbox N/A
    Potential energy Average, maximum, minimum, or total N/A
    Residence time Average, maximum, minimum, or total N/A
    Rotational kinetic energy Average, maximum, minimum, or total N/A
    Torque Average, maximum, minimum, or total Magnitude, X, Y, Z
    Total energy N/A N/A
    Total force Average, maximum, minimum, or total Magnitude, X, Y, Z
    Velocity Average, maximum, minimum, or total Magnitude, X, Y, Z
    Voidage [1] Total N/A
    Volume Average, maximum, minimum, or total N/A
    Custom property Average, maximum, minimum, or total Depends on the number of elements
    1. Select the Total over time checkbox to cumulatively add the number of particles over a period of time.
      As you step forward through the simulation, the total number of particles will be recorded. Cumulative particle totals for bin groups only works when stepping forward through your simulation: if you jump back, the totals may not be accurate. all Geometry or a particular section (as specified in the Creator).
  5. For Setup Selections - Type, select the elements in your model to include.
    By default, all particles are included in the group, and if you select No Geometry or No Contacts, the data will not be exported for the selected Query type.


    1. For any element, select All, None, or a few elements from the dropdown list.
    2. For selected elements, select the checkbox to include all elements.
      Elements Filter Options
      Particles All Particles, No Particles, Selected Particles
      Geometry All Geometry, No Geometry, Selected Geometry
      Surface - Geometry Contacts All Surface-Geometry Contacts, No Surface-Geometry Contacts, Selected Surface-Geometry Contacts
      Surface - Surface Contacts All Surface-Surface Contacts, No Surface-Surface Contacts, Selected Surface-Surface Contacts
  6. For Setup Selections - Representation, specify the following details:
    For Specify
    Display Mode Indicates how bins are rendered in the Viewer for bins and bin groups. Options are:
    • Always

      Always displays all bins.

    • If Populated

      Displays bins only when they contain elements enabled in the type filter.

    • Never

      Does not display bins. Since several selections may not be recommended, select this option to turn off specific selections.
    Display Options Click Edit to view the display options. Indicates which query is displayed in the Viewer, and allows you to set the highlighting and coloring options for individual bins (sub-selections).
    On Screen Display
    • For bins and bin groups, select the checkbox and then select the selection group query to be displayed in the Viewer.
    • For Grid and Geometry template selections, select options to highlight and color sub-selections. You can color bins using one of the following options: highlighting individual bins, or coloring bins using a specific query
    Highlight Sub-Selection Select to highlight a particular bin in the bin group. Only one bin can be highlighted at a time.
    • Bins in grid bin groups are identified using an ID matrix.
    • Bins in imported template selections use the Geometry names from the imported file (if available).
    Sub-Selection Coloring Select a query from the dropdown list. Options are:
    • Value Range

      Set the minimum and maximum query values either manually or read from the model by clicking Update. This takes the current maximum and minimum values of the selected query.

    • Auto-update

      Select to automatically update according to the Time Step being viewed. Bins will then be colored depending on the approximate range they fall in. The colors used are fixed from blue (minimum), through green, to red (maximum).

    • Legend

      Select to display a color legend in the Viewer.

    • Opacity
      Select to vary the opacity of the bin coloring. Bin groups can be colored according to any pre-defined query. For example, bins can be colored by the number of collisions taking place in them, or by the average speed of the particles they contain.