A fully programmable clock synthesizer provides the appropriate timebase signals to
allow the VOF to accurately generate any desired video format whose clock frequency
falls between approximately 7 MHz and 125 MHz. This includes NTSC (RS170) and
PAL on the low-end, standard 60 Hz non-interlaced and 30 Hz interlaced 1280 x 1024,
and 120 Hz half-resolution stereoscopic video formats (512 x 1280). Recently, the
HDTV (1920 x 1024) timing was added to allow direct output from MultiBuffer VGX
and VGXT systems to HDTV displays. Custom video formats are available, with no
need for hardware changes, by special arrangement with Silicon Graphics.
Genlock is available for both high- and low-resolution video signals from the
Broadcast Video Option board.
VTR Deck Control
Videomedia's VLAN is available as a video option. This enables easy frame editing
for recording animations directly to video tape recorders. This option requires one
VME slot as part of the VideoFramer or VideoCreator options.
3.2.3 Stereo Viewer
Every PowerVision system is shipped stereo-ready with a Multisync high-resolution
monitor. To use the stereoscopic viewing option, users need the StereoVieW(tm) option,
including an LED emitter synchronized to the monitor refresh rate of 120Hz and a
pair of lightweight, LCD shutter glasses.
3.3 PowerVision Graphics Features
3.3.1 Texture Mapping
Computer graphics displays can be greatly enhanced with the use of texture mapping.
and the IRIS PowerVision architecture supports high-quality texture mapping of
geometric surfaces at interactive rates.
Texture mapping has traditionally been used in fields such as visual simulation and
computer animation to enhance scene realism. Textures can add vegetation and trees
to barren terrain models without adding geometric complexity. Labels can be applied
on computer modeled package designs to get a better appreciation of how actual
products will look. In addition to scene realism, interactive texturing also facilitates
visualization of user data. Patterns mapped on to geometric surfaces can provide
additional motion and spatial cues that surface shading alone cannot provide. For
example, a sphere rotating about its center appears static when displayed as a shaded
surface; however, by affixing a pattern to the sphere, its motion is easily detected. In
such fields as scientific visualization, it is desirable to display changing properties of
an object on its surface. Interactively texturing a surface as a function of these
changing properties is an excellent way to accurately visualize this information.