Comparing Objects and Simulation Trees

Simcenter STAR-CCM+ provides a comparison tool that allows you to identify differences visually between individual objects or between simulations (in the same Simcenter STAR-CCM+ session). You can observe differences in object properties such as model settings, boundary conditions, and meshing parameters.

This tool appears as a separate window. When you select a highlighted child object, the property values are shown in a pair of Properties windows below the Explorer windows. You can edit property values within these windows.

Comparing Objects

To compare exactly two nodes in the same simulation, do the following:

  1. Multi-select the nodes.
  2. Right-click one of the highlighted nodes and select Compare.
  3. View the nodes side-by-side in the Comparison window.

Alternatively, use the following technique which lets you compare objects within a simulation or between simulations:

  1. Select File > Open Empty Comparison View.

  2. Drag any pair of nodes from the simulation tree into the Comparison window.

    NoteIf a comparison window already has a node, the node that you drag replaces it.
  3. To compare objects between simulations, drag one node at a time from each simulation tree into a different half of the Comparison window.

Comparing Simulations

When comparing simulations, the comparison tool duplicates the object trees of the two simulations that you want to compare. In these duplicate object trees, highlighted root objects guide you to the child objects that are different between simulations.

A typical workflow for comparing simulations is as follows:

  1. In the same session of Simcenter STAR-CCM+, open the two simulation files that you want to compare.

    Remember that Simcenter STAR-CCM+ checks out one license per simulation. However, it is possible to compare two simulations in read-only mode, which does not consume a license.

  2. With either simulation window active, access the comparison in one of the following ways:
    • Select File > Compare with [simulationName].
    • Right-click the root node of the simulation tree and select Compare with [simulationName].

    The appearance of the menu varies with the number of open simulations. If you have more than two simulations open, the simulation names are available for selection in a submenu of the Compare with menu item. However, if you have only one simulation open, this menu item is inactive (grayed out).

    After you execute this menu action, the comparison window appears in the workspace.

  3. Navigate through the object trees. To find differences consecutively, use the following techniques:
    • Next difference: right-click on a node and choose Select Next Difference, or press <Shift>+<Alt>+<Down> arrow.
    • Previous difference: right-click on a node and choose Select Previous Difference, or press <Shift>+<Alt>+<Up> arrow.

    Observe the following conventions for node highlighting:

    • No highlighting: this node, and its children (if any), are identical across simulations
    • Light purple: one or more children of this node differ between simulations
    • Dark purple: this node or property is different between simulations
    • Green: this node or property appears only in one simulation and not the other
  4. Compare and change properties of nodes in the comparison windows.
  5. To locate a node in the main simulation tree, right-click it in the comparison tree and choose Select in Simulation.
NoteYou can only have one comparison window open at a time. Suppose that you have three or more simulations open, and you launch the Compare with action with the third simulation. The existing comparison window closes and a new one appears with your latest comparison choices.