3DLABS Oxygen VX1 - Manual (Page 26)

The Oxygen VX1/Oxygen GVX1 Driver
17 3Dlabs Oxygen VX1/GVX1 User’s Guide
buffer is sub-divided into sub buffers which are used in conjunction with a queued
DMA mechanism to reduce latency in the system. The number of sub buffers can be
set. Setting it to 2 will disable the queued DMA mechanism.
• Overlay / Alpha Mode provides additional control of the overlay plane capabilities
exported in the OpenGL pixel formats. It is specific to just two applications: Alpha
Only is required by the Alias / Wavefront application “Maya” where retained alpha
planes are required (e.g. the particle system package), and Overlay Only is for the
Parametric Technology application “Pro/3DPaint”. Selection of the above
applications from the application menu cause the correct mode to be set
automatically. The Dynamic setting should be chosen for all other cases.
• Wait for Vblank lets you determine whether the OpenGL driver will attempt to
synchronize screen updates to the vertical blanking interval. Smooth animation of 3D
applications can be achieved by rendering (drawing) to an off-screen window/
desktop-sized color buffer and copying or swapping the contents to the displayable
front buffer at the completion of each frame.
Visible "tearing" can occur if Wait for VBlank is not selected. Disabling this option
gives the highest rendering frame rates of double buffered applications. You should
disable this option, for instance, when running benchmarks.
• Stereo View Support can be enabled (checked) and disabled (unchecked). This option
provides control over the export of stereo capable OpenGL pixel formats. You should
enable this option when there is a requirement to run OpenGL applications that
require stereo support, since additional graphics memory resources are consumed
when stereo is enabled. The stereo support provided is quad buffered and frame
interleaved. You must restart your system for a change to this setting to take effect.
For additional information, see “Configuring your Oxygen GVX1 Card for Stereo
Viewing” on page 21.