Texas Instruments TI-89 Manual Book page 183

Examples of Style
Settings
Tip: is faster
WIRE FRAME
to graph and may be more
convenient when you're
experimenting with different
shapes.
Be Aware of
Possible
Optical Illusions
Note: These examples
show the graphs as
displayed on the screen.
Note: These examples use
artificial shading (which is
not displayed on the screen)
to show the front of the box.
166 Chapter 10: 3D Graphing
To display the valid
Style
highlight the current setting and
press B.
¦
Shows the 3D
WIRE FRAME —
shape as a transparent wire
frame.
¦
HIDDEN SURFACES —
shading to differentiate the
two sides of the 3D shape.
Later sections in this chapter describe
(page 167) and
CONTOUR
The angles used to view a graph (
eye
variables) can result in optical illusions that cause you to lose
perspective on a graph.
Typically, most optical illusions occur when the
negative quadrant of the coordinate system.
Optical illusions may be more noticeable with box axes. For
example, it may not be immediately obvious which is the "front" of
the box.
Looking down
from above the xy plane
eyeq = 20, eyef = 55, eye = 0
To minimize the effect of optical illusions, use the
dialog box to set
Style = HIDDEN SURFACE
settings,
Uses
CONTOUR LEVELS
(page 171).
IMPLICIT PLOT
eyeq, eyef
Looking up
from below the xy plane
eyeq = 20, eyef = 120, eye = 0
.
,
WIRE AND
, and Window
eye
eye angles are in a
GRAPH FORMATS