Lecture Notes

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3/25/02

• Views
• The most effective to set up views is to use the edit cone of vision selection.
• Since views are composed of eye points and center of interests (creating vectors) one has a set of data that can be manipulated.
• Editing cone of vision allows easy manipulation of this data graphically.
• When the tile views displayed by edit cone of vision are visible, one can simply click on the eye point, center of interest, hither and yon plains, and the line of sight itself to adjust the view.
• When data is manipulated in the x and y tile view, the z data remains unchanged….when working in the x and z plain, the y data remains unchanged.
• To change which quadrant the user is working in, simply click in the desired quadrant. A dark border will appear around the active quadrant.
• To exit the edit cone of vision click the lower of the two close box symbols. (Note: make sure not to click the upper X, as this will close Form· Z).

• Topology and transformations
• Topology and the relationship between points
• The turquoise box next to the selection tool allows the user to very precisely interact with specific aspects of an object. The user can choose to operate on the object, a face, a segment, or a point
• Note: once the topological layer is set, it remains until changed.

• Group command
• Two or more objects can be placed into groups.
• To place objects into groups, change the topo level to object, select two or more objects, select the group commend, and click anywhere on the screen. A new group has now been made.
• Now, if one changes the topo level to group, if any one of the objects that were just placed into a group is selected, the entire group of objects is selected.
• To break a group, select the group, choose the ungroup tool, and then click on the screen.

• Attributes
• Attributes can be thought of as characteristics.
• There are two types of attributes: descriptive and organizational.
• Descriptive-pictorial quality: color, linetype, surface style, ect.
• Organizational-describe something about how some data is arranged.
• Layers and groups are common examples.

• Transformation-formal computer term. Any operation that causes a change in existing data.

• The four basic  transformations:
  1. move (translation),
  2. rotate, scale,
  3. scale (either separately in x,y,z direction or by a common factor),
  4. and mirror.
• To apply a transformation: select correct topo level, select object, and click on the screen and move the object to the desired location, for example.
• When objects are transformed, one has several options. One can move the object itself, one copy of the object, continuous copies, repeat copies, or multi copies.

Note: all of these that create copies, are more than just transformations.