Selecting Objects in the Graphics Window

Simcenter STAR-CCM+ provides a toolbar that lets you select objects in a scene with precision.

The selection tools come in three varieties: rubberband, zone, and depth. You can control each one by a filter that lets you select parts by curve, surface, or volume.

Add any volumes, surfaces, or curves that you wish to select using these tools to the scene displayers. For example, when importing CAD files, part curves are not included in the geometry displayer by default, so are not available for selection.

The Depth Select tool lets you select objects that are hidden from view in the scene.

Selecting in a Rubberband

This technique lets you define a specific area in the display by clicking two points that define the opposing corners. Objects within that area are selected. You can use the selection filter to control whether this selection includes volumes, surfaces and/or curves.

  1. Click the (Rubberband Select) button to activate this tool.
    After you click the first point in the display, the tool draws a rectangle and finishes it once you click the second point.

  2. Press <Esc> to cancel the drawing process.
    The resulting selection is highlighted in the display. In the example that illustrated here, the setting is for curves in a 3D-CAD view scene.

  3. If you want to deselect the zone, press and hold the Shift key, then click the (Rubberband Select) button and select the specific area.

Selecting by Zone

This technique lets you draw a zone by clicking and dragging to create a series of connected points. Objects within that zone are selected.

You can use the selection filter to control whether this selection includes volumes, surfaces and/or curves.

  1. Click the (Zone Select) button to activate this tool. Each click in the display adds a point that is connected by a segment to the previous point.


  2. Right-click the last point to finish the zone.
  3. Press <Esc> to cancel the drawing process.
    The resulting selection is highlighted in the display. In the example that illustrated here, the setting is for surfaces and curves in a 3D-CAD view scene.

  4. If you want to deselect the zone, press and hold the Shift key, then click the (Zone Select) button and select the specific area.

Selecting Behind Other Objects

This technique lets you select objects that are obscured from view. It is available in CAD and in regular visualization scenes. To select an object behind other objects:

  1. Click the "Select Hidden Object" button in the Selection toolbar.
    • To add the hidden object to an existing selection of objects, hold down the <Ctrl> key before you click in the scene.
  2. Click in the scene at the approximate location of the part that you wish to select.

    This action does the equivalent of "shooting a ray" that is perpendicular to your view. The only objects available for selection are the ones that the ray hits.

  3. Use the mouse wheel or arrow keys to iterate through the choice of objects.

    Green highlighting of an object means that the particular part is available for selection. Yellow highlighting means that the object already has been selected previously, and selecting it again would deselect it.

    NoteRotating the scene is allowed when in iteration mode. This capability lets you check the order of the results along the ray.
  4. To select the object, press the <Space> bar.
    • To add objects to your selection, hold down the <Ctrl> key while shooting another ray.

Filtering the Selections

If you have a wide variety of parts in the object being simulated, you can filter the selection based on curve, surface, or volume.

The result will be that, as you carry out mouse actions in the display, only the type of part you specify is selected.

Click the (Selection Filter) button. It activates a menu.

By ticking the checkbox next to an option, you can specify the type of part selected. Since selecting volumes always includes the selection of curves and surfaces, the options in the menu change their selection automatically depending on which checkbox you tick, providing the following set of possibilities:

  • Volumes
  • Surfaces
  • Curves
  • Surfaces and curves

The meaning of these terms for the specific part type varies depending on what type of display you are accessing:

  • For 3D-CAD views:
    • “Volumes” are 3D-CAD bodies.
    • “Surfaces” are the faces of the 3D-CAD bodies.
    • “Curves” are the edges of the 3D-CAD faces.
  • For geometry views displaying geometry parts:
    • “Volumes” are geometry parts.
    • “Surfaces” are part surfaces.
    • “Curves” are part curves.
  • For views displaying regions and boundaries:
    • “Volumes” are regions.
    • “Surfaces” are boundaries.
    • “Curves” are part curves.
The filter also controls how the left-click selects objects. For example, if it is set to select surfaces only, a click on a part selects only the surface.

However, if selection of volumes is specified, then a click in the exact same place selects the volume.