title: Linking
author: tiglari

Linking is also new and rough around the edges; it's purpose to
make 'permanent glue', so that faces that are meant to stay stuck
together are more likely to do so.  The 'Glue to tagged' command
will link the glued and glued-to faces if the 'Link on Glue'
option from the Options menu is checked (by default it isn't,
since this is new behavior).  When faces are linked, various
things happen:

<UL>
<LI>If one of the faces, or a poly, group or entity containing
one of the faces, is dragged, then all of the faces linked to
that face are dragged along too.

<LI>If some operations other than dragging result in some linked
faces no longer being coplanar, they are all drawn in dotted
red (and it's easy to get the coplanar again).  If one of them
is selected, then it and those coplanar with it are drawn in
dotted blue instead (doesn't always work).
</UL>

The 'Linking' submenu for faces provides control over linking
effects.  Its commands are:

<UL>
<LI>Glue linked faces - all faces linked to the selected one are
glued to it.  This is the basic technique for fixing things up
when linked faces become unaligned (there are many different
things that can cause faces to move in QuArK, and it's probably
not sensible to try to track them all automatically, and very
un-sensible to assume that you're doing it successfully ..).

<LI>Select linked faces - all the faces that are linked to
the selected one become a multi-selection.  This gives quick
access to the face-rotating handles.

<LI>Unlink face - the selected face is detached from the others
it's linked to.

<LI>Unlink all - all the faces linked to the selected face are
unlinked from each other.

<LI>Link face to tagged - links the selected face to the tagged
one, without moving it (so the dotted red lines appear).  I'm not
sure if this one has a legitimate use, maybe it will disappear.
</UL>

There are also two more options in the Options menu:

<UL>
<LI>Glue linked on drag - when something is dragged, things linked
are dragged with it.  On by default.  If it's off, dragging
something away from what it's linked to produces the dotted
red lines.

<LI>Multiselect on linked drag - if this is checked, the stuff
that's dragged on a linked drag becomes the multiselection (QuArK
does spontaneously for some reason, I'm not sure if it's useful,
but I decided to make turning it off optional).
</ul>

<A name="later"></a>There is also a linking item on the speed menu for polys, groups
and brush-entities, 'Glue Linked'.  This causes all the faces
linked to some face in the group or whatever to snap to that
face (for fixing things up when movements get linked faces out
of alignment).
