2.4.1.1. Creating a snapshot
To draw on a particular lecture slide or group of topics, a snapshot must first
be created. Creating a snapshot is like taking a picture of the current viewing
window, capturing the current hierarchy of the lecture.
For slide mode this is like creating another layer of the current slide.
Continuous mode makes these snapshots much more useful, as they capture
the lecture at a particular time. Because continuous mode-presentations
dynamically change, snapshots are necessary to make sense of drawings
as the background of the drawings change.
Snapshots act like the background for drawings.
To facilitate actual drawing, each snapshot can contain any number of
overlays. Overlays can have different editting and viewing configuration,
making them useful for an interactive classroom experience. Every snapshot
created will have at least one default overlay and more can be added.
Controls are available to change the opacity of both the foreground and the
background of a particular overlay. Z-Ordering controls are also available
to change the ordering of graphics on a screen. To facility these features
the user can use the Snapshot Window to manage the overlays, described in
section 2.4.1.4.
Snapshots have permissions based on the overlays attached to the snapshot. If
a student has viewing permissions for any of the overlays contained in a
snapshot then that snapshot is visible to the user. By default snapshots created
by instructors will contain an overlay with view permissions for everyone and
edit permissions for only the instructor. Student snapshot creation defaults
to an overlay that only the student can view and edit. For information on how to
view and change these permissions, refer to section
2.4.1.3.
Figure 2.4.1.1a: Creating a new Overlay.
There are two methods to creating a snapshot. The first is the unlinked snapshot;
a snapshot that is not linked to any particular topic. This snapshot will be
places in the Desk Drawer with all other unlinked snapshots.
Figure 2.4.1.1a illustrates how to create an unlinked snapshot from the
Presentation window. The user can also select Create Snapshot from
the Presentation menu option. To link this snapshot to a specific
topic see section 2.4.1.3.
A user can also directly create a snapshot on a topic. To create a linked
a snapshot, the user right-clicks on the desired topic and chooses the
'Create Linked Snapshot' option. This combines the act of
creating the snapshot and linking it the desired topic. Figure 2.4.1.1b
illustrates the topic context menu shown when the user right-clicks on a
lecture topic.
Figure 2.4.1.1b: Result of right-clicking a Topic
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