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Parameter Modification & Regeneration
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Tutorial V - Parameter Modification & Regeneration

  This tutorial will cover modifying parameters of a parametric model and regenerating new volumes. For this example, we are using the $(UGII_BASE_DIR)/ugcast/parts/fea/fea_solid.prt file which is a model of a bracket (below). The objective of this tutorial will be to resize the hole in the bracket.

Resizing Parameters

  When a model is loaded, each volume is checked for the existence of a master model. If it exists, a folder will be created in the Structure Tree named "Parameters" that will contain a list of exposed parameters for that volume.

  Each entry will be labeled with the name that it was assigned when created in its native CAD system.

  To modify the hole diameter, select the parameter labeled "D" and choose Edit... under the Edit/Master Model menu.

Edit Feature Parameters Dialog

  The Edit Feature Parameters Dialog displays as read-only data the name of the parameter being modified and the branch feature information. Below the branch information, there is a list box that can contain N values for the selected parameter. Each of these values can be modified by left clicking on the value, and then typing the new value in the text field below.

  In our example (left), we will change the diameter of the hole to a value of 10.0.


  The original value of any parameter can be recovered by selecting the parameter and choosing Revert from the Edit/Master Model menu. The entire set of parameters can be reverted by selecting the "Parameters" folder then choosing Revert. The Revert function always returns the back to the value at the time the volume was created or read from file.


  After modifying the values of the desired parameters, the volume must be regenerated. To regenerate, select the volume by left clicking in the Structure Tree, then choose Regenerate from the Edit/Master Model menu. If the regeneration is successful, a new volume with the modified parameters will be created.

  The underlying CAD kernel will determine if the part can be regenerated based on the dependencies of the parametric model and the new values that were entered. It is possible to over constrain the part being regenerated which can yield undesirable results or prevent the regeneration from taking place altogether. How the model will be used in terms of resizing should be taken into account when the model is built.

  Inspecting the new regenerated part (below) shows the hole modified to half the original size.

Responsible NASA Official: William T. Jones
Site Curator: William T. Jones
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Last Updated: Oct 2, 2003