Edit Other Objects Widget Help


This widget allows the user to drop objects into the scene. These objects can be scaled and oriented to point to structures of interest in the scene. Information about them can be saved so that whenever the image is displayed with DAVE the added objects will appear. Currently arrows, 3D scale bars, 2D scale bars, flat polygons, and text strings are the only allowable objects. The crosshair must be positioned at the location you wish to drop an object. The crosshair can be turned on from the menu. See the Edit Crosshair Widget (from the Edit menu in the DAVE Master Widget) on how to position the crosshair.

Creating and Manipulating Objects in the Scene

Adding and Positioning Objects in the Scene

Various types of objects can be dropped at the crosshair location. By default an arrow is dropped. This can be changed by either toggling through the different types (via clicking with the left mouse button on the box labeled "Arrow") or by choosing the desired menu entry (pressing the right mouse button while over "Arrow" to call up a menu of objects from which to choose). The objects size (in pixels) can be specified to changing the numbers in the "Width" and "Length" boxes. If the object is a scale bar, then "width" represents the length of the x and y axis and "length" is the z axis length. The object name can be typed into the "Name" box. If the object is a text string the length and width boxes are ignored. The object name can be typed into the "Name" box. In the case of a text string, the object name is the text that will be placed into the scene (it can be more than one word). The font size and color can be selected by choosing the More Objects Options item from the menu. See the help there for more details. Note: the text will rotate with the scene, but the text orientation will always remain parallel to the screen. If the object is a polygon, the object width is interpreted as the radius (I think) of the polygon. The object length field is the polygon's depth in z. Polygons are only represented as wireframe outlines. A length greater than 1 just causes multiple wireframes to be drawn at different depths. By default an 8 sided polygon is created. This can be changed by choosing (prior to dropping the object into the scene) "Number of Polygon Sides ..." from the menu. Currently font color and arrow and scale bar size must be specified prior to dropping the object into the scene. They cannot be changed once the object is created (but the object can be deleted and a new one created). The axis labels for the 3D scale bar can be set from the More Objects Options widget, as can the axis colors. Once the object type and attributes are specified and the crosshair is positioned correctly, simply click on "Drop Object At Crosshair". The object should appear in the scene. The object can now be rotated by clicking on "Rotate Current Object". In this mode, moving the cursor in the viewing window (with the left mouse button held down) will cause only the object to rotate, not the entire scene. Note: currently the crosshair must be displayed for you to be able to rotate the object. The 2D scale bar (unlike the other objects) does not rotate with the scene but stays fixed wherever it is initially dropped on the screen. You must be in the HOME position prior to dropping the 2D scale bar. (if you have redefined the definition of HOME, e.g. with Set Home, you must use RESET from the Stuff menu to change it back to its default first).

Modifying Objects

An object's orientation and existence can be modified. First the desired object is specified by either toggling through the list of currently existing objects (left mouse button) or picking from a menu (right mouse button) This is done while the cursor is over the name of the current object (i.e., in the box below the words "Current Object"). Once chosen, the object can be rotated as described above or deleted by picking the "Delete Current Object" button.

The following 2 paragraphs may be incorrect, see the comment following them. The color (and transparency) of a dropped arrow can be changed by going to the Edit Object Materials widget (which can be gotten directly from the DAVE Master widget or from the Object Properties menu in the Edit Objects widget). The new objects should show up on the Object menu in that widget. See the help there for more details. Currently there is no easy way to change the display mode of an object from a surface to a wireframe. You have to write out the new objects and change the line in the file which says status=SURF to status=MESH. Then start up a new session of DAVE with this object file.

This paragraph supercedes the preceeding paragraphs (I think). The color of a dropped arrow can be changed by going to the More Objects Options widget (which can be gotten directly from the menu). The new objects should show up on that widget. See the help there for more details. The arrow can also be changed into a wireframe and its color changed. NOTE: These options may still be buggy, they haven't been used much yet.

Saving Objects

You can save all of the objects that have been added by using the Write Objects... option from the File menu in the DAVE master widget. See the help there for more details. Polygons which have been saved can be automatically moved and scaled by ~lml/vision/bin/best_fit. This program attempts to change the polygon's position to fit the data better. See the program for more details.
Copyright 1995 by Lawrence M. Lifshitz and the University of Massachusetts Medical School. All rights reserved.