visible object. This is discussed in <A HREF="VisClass_e.htm#87564"> Positioning Visible Objects</A>
.</P>
<P>
Often applications may need to change something about a visible object or the tree it's in. When this happens, the application must force a visual update by invalidating either the geometry or the image (or both) of the object and then calling <CODE>
MGS_VIS_VUP_UPDATE_WIN_GROUP</CODE>
. To mark any object invalid, the application must call <CODE>
MSG_VIS_MARK_INVALID</CODE>
.</P>
<P>
Many visible 