TYPE: SOP State
TITLE: Select Operation

The select operation lets you preselect geometry for the next modeling
operation.

The normal way to model in houdini is to first choose the operation you would
like to perform and then select the geometry on which to perform that operation.
The select state allows you to preselect some geometry that will be used for the
next operation to perform.

General Selection Hints:
(Note that these hints apply to both the select state and the selection stage of
other operations.)

1. The buttons at the left side of the viewer pane let you change the type of
selection (eg. points, primitives, edges, etc.)  The
${h.pane.gview.model.seltypepoints}-${h.pane.gview.model.seltypeconedges} keys
can also be used to change the selection type.

2. The default selection mode is "replace" mode, where newly selected geometry
replaces the current selection.  To quickly use "toggle" mode while in
"replace", hold the shift key while selecting.  While in "toggle" mode, clicking
on already selected geometry will remove it from the selection, and clicking on
unselected geometry will add it to the selection.  The selection mode can be
changed to "replace", "toggle", "add", or "remove" by clicking on the menu at
the left hand side of the viewer.

3. The default selection style is "box picking".  This means that clicking and
dragging the mouse will draw a box, and the current selection rule will be
applied to everything in the box.  The selection style can be changed to "box
picking", "lasso picking", or "paint picking" via the menu to the left of the
viewer.  Lasso picking lets you draw freehand selection regions.  Paint picking
lets you drag the mouse over geometry to select or unselect it.  While paint
picking, the left-mouse-button uses "replace" mode, Shift-left-mouse-button uses
"add" mode, and the middle-mouse-button uses "remove" mode.

4. The "select whole geometry" toggle at the left of the viewer lets you pick an
entire geometry object by clicking on any part of it.  The keyboard shortcut for
this toggle is ${h.pane.gview.model.fullselection}.

5. The "front/back polygon" menu at the left of the viewer lets you select front
and back facing polygons, only front facing polygons, or only back facing
polygons.  This menu is useful when working in the UV viewer.

6. While selecting, pressing Ctrl-right-mouse-button will bring up a menu.  In
this menu are options to select all geometry, no geometry, or toggle the
selection.  Keyboard shortcuts for each menu item are also listed.  Also in this
menu is a toggle to say if selecting from all objects is allowed.  If it is
allowed, picking geometry in other objects will create object merges.

7. Some operations, like Transform and Edit, let you select geometry and drag it
while in selection mode.  The moment you drag the geometry houdini exits
selection mode and begins to change the parameters of the current operation in
order to drag the geometry.  If you do not want to accidentally drag geometry,
use the middle-mouse-button to select it instead of the left-mouse-button.
