IRIS 3010, User Manual

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Version 1.0 SERIES 3000
IRIS OWNER’S GUIDE 9-9 Demonstration Programs and Gifts
A wireframe outlining the basis points appears. The database of
basis points is sent to the new window. The surface is subdivided
into small quadrilaterals and an illumination model is calculated.
The surface is displayed as an array of dots.
3. Detach from the surface editor window and select the rendering
window for input. Rotate the object by pressing the mouse button
corresponding to the axis of rotation and moving the mouse from
left to right. Because the operation is double-buffered, the motion
seems smooth.
4. To switch the display to splines, type
s
. To return to the point
array, type
p
. To turn depth-cuing off or on, type
d
. Use
z
to
Gouraud-shade the object.
When you switch from the point or spline array to the shaded
picture, the system switches itself from double to single buffering to
accommodate z-buffering. Z-buffering is used for general-purpose
hidden-surface removal.
5. Type
c
to select a new color ramp to smooth shade all objects on
the screen. Another way to change the surface color is to bring up
the cedit , showmap and interp graphics windows and use them to alter
the color ramp that shades the surface.
The rendering program can also be executed directly without going through
the surface editor stage to modify the database. To do this, type: zshadecar ,
zshadeegg , zshadeabstract or zshadejet .
NOTES: Hardware z-buffering is not available on
machines that do not have 32 bits of image memory per
pixel. Do not try to use the rendering window without a
32 bitplane system.
If a double-buffered program not set up to work with
the rendering demonstration programs is currently
open, the rendering program does not shade the object.
It prints a warning message in the console window.
Kill the outstanding double-buffer windows and try again
to shade the object.
9.2 Gifts
The contents of the directory /usr/people/gifts varies with the current software
distribution. Gifts are provided as interesting and possibly useful examples, but
they are not supported and are often not documented.