SFA Sundials Explanation

This document explains the interaction techniques of the sundial menus along with lists of the available sundial menus in SFA.

This document is broken down into two major sections, one describing basic sundial interaction and one describing the sundial menus available in SFA of the Draw class.


Basic Sundial Interaction

When SFA is configured to use the Minimal Reality (MR) Toolkit for tracker interaction, a form of menus is used for the majority of basic tasks, allowing the user to execute these task without having to put down the trackers.

The sundial menu interaction technique was created by Dr. Chris Shaw. It is an extension to the MR Toolkit, found in the TwoHand Library . Sundials are pie menus popped up at the location of the cursor controlled by the non-dominant hand when the user presses the middle button on the non-dominant hand's bat. Once the menu is up, the user selects which section of the pie menu they wish to activate using the orientation of the non-dominant hand's bat. For example, for a sundial menu with four quadrants, if the user wished to activate the menu item in the leftmost quadrant, he or she would pop up the menu, and twist the non-dominant tracker to the left. A 'shadow stick' (a three dimensional object intially perpendicular to the pie menu) shows which pie menu item (if any) would be activated if the user released the button at that time. When the shadow stick is over a particular menu item, the text for that menu item highlights, giving another visual cue that that item would be selected.

Note that some standard mouse menu operations don't lend themselves well to sundial interaction. For example, any menu item which will pop up a dialog box requiring further interaction with the mouse does not translate well to sundial menus. For this reason, items such as File/Save, File/Load, Edit/Mappings, etc. do not have sundial menu counterparts.

Just like mouse menus, sundial menus supports hierarchical menu structures. If a particular sundial menu item is a parent to another menu (called the child menu), an arrow will be drawn at the edge of the sundial menu indicating that if the shadow stick is held over that menu section for a moment, the appropriate child menu will be brought up for the user to select from.

If the user decides not to activate any menu sections in a sundial menu, they can release the button while the shadow stick is still over the hollow section at the center of the sundial menu.


Sundial Menus in SFA

The following sundial menus are available in SFA:




Top Level Menu

The top level sundial menu in SFA is used exclusively to activate the other menus. Therefore the only items it has are parent nodes for each of the four other available child menus.

Cursor Control Menu

The cursor control menu is used to control various aspects of the MR parameters controlling the viewing of the scene. It has four options available: Scale Up, Scale Down, Origin, and Boresight.

The Scale Up and Scale Down menu options are used to control global scaling of the entire scene. Each selection of these menu options scale the scene up by a factor or 2 or down by a factor of 1/2.

The Origin menu option resets the location of the cursors in the three dimensional space so they are in the 'sweet spot' of interaction. If upon starting SFA you find the trackers are not centered in the scene, a reorigin should fix this problem.

In general, it is a good idea to do two scale downs and a reorigin at the start of SFA to get the most interactive experience with SFA with trackers.

The Boresight functionality is a throwback to old SFA functionality and is no longer present. The menu option will be removed in the near future.

Step Sizes (X, Y and Z)

X, Y and Z size step sizes in SFA are used to filter out the number of glyphs drawn in order to increase rendering glyphs. See the draw class documentation for more information on glyph filtering for rendering speedups.

Glyph Types Menu

This menu duals the combination box found on the main toolbar of SFA. It allows the user to specify the scalar glyph type currently being drawn. Upon selecting one of these menu items, that will now become the current scalar glyph type. NOTE: Currently this menu and the combination box on the toolbar are not synchronized with each other. Selecting a glyph type on one menu will cause the glyph type being drawn to change, but the other menu will still say the old glyph type. In other words, SFA always uses the glyph type most recently selected by the user, but this will not necessarily be the glyph type described in the opposite menu.

The glyph types available are: Point, Dot, Cube, Sphere, Circle, Pyramid Cube, Pyramid Octa, Octa Cube, Turbulated Cube, and Superellipsoid.
 
 

back to main page


James Hall
Last Modified: June 17, 1999