Tutorial IV - Feature Suppression & Regeneration
This tutorial will cover suppressing features of a feature based
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
suppress the hole in the bracket.
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 "Features"
that will contain a list of features for that volume.
Each entry will be labeled with the name, the id number in
parenthesis, and the number of children in brackets. Each of these can
be expanded by left clicking on the green icon. This will display the
features that are children.
Marking for Suppression
In order to remove the hole in our example part, we must mark the
"SIMPLE_HOLE" feature for suppression. This is accomplished
by right clicking on this feature and selecting the Suppress toggle
button in the Edit/Master Model menu. The features that are marked
for suppression will have their icons grayed out.
The original value of the
feature suppression flag can be recovered by selecting the feature and
choosing Revert from the Edit/Master Model menu. The entire
feature tree can be reverted by selecting the "Feature"
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 marking the desired
features for suppression, 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 features suppressed will be created.
The underlying CAD kernel will determine which features should be suppressed
in addition to the marked features. The structure of the feature based model
will determine this selection. It is possible that certain dependencies
exists that will yield undesirable results or prevent the regeneration from
taking place altogether. This fact should be kept in mind when attempting to
suppress features of models that were not constructed to support it.
Examining the resulting Structure Tree
of the new regenerated volume (right), you can see that seven of the nine
child features of "SIMPLE_HOLE" feature were actually suppressed.
This was determined by the underlying CAD kernel (in this case, Unigraphics).
Also note that the resulting model (below) does have the hole removed,
however, the "BLEND (10)" feature was also suppressed which has
changed the overall profile of the bracket. This is due to the way the part
has been constructed, and due to this structure suppression of just the hole
itself is not possible.