Opengl Environment; Opengl Overlay Planes Support; Introduction; Implementation - Asus 3DP-V500TX User Manual

Table of Contents

B. OPENGL ENVIRONMENT

Overlay planes provide a method by which OpenGL applications can render over

screen areas in a nondestructive way. A typical use of such functionality would be to

draw dialog boxes above a rendered 3d scene. There would be no need to save and

restore from a bitmap or re-render the scene when the dialog is cleared as the stan-

dard, main-plane, rendering remains intact. Overlay planes are used by many high

end OpenGL applications as they are a common feature on Silicon Graphics hard-

ware.

Overlay planes are not provided as a standard part of OpenGL in the way that stencil

or depth buffers are. On Windows NT Microsoft define a standard overlay plane

specification as part of the WGL interface. This interface is used by Windows NT

OpenGL applications which require overlay functionality, notably Softimage.

The Microsoft overlays standard provides for up to 15 levels of underlay and 15

levels of overlay in addition to the main rendering plane. Each level of underlay or

overlay, referred to as a layer plane, has it own layer plane descriptor structure.

OpenGL.SupportSoftimage: This variable is used to optimise the OpenGL driv-

ers for use with version 3.01 of the SoftImage rendering package. We do not recom-

mend use of this variable unless you will be using the SoftImage application. If this

variable is defined and set to 1 then the optimizations will be enabled.

A system reboot is necessary for changes in this variable to take effect.

OpenGL.SupportSoftimage351: This variable will optimise the drivers for ver-

sion 3.51 of the SoftImage rendering package. Once again we recommend that you

only use this variable when using Softimage. If this variable is defined and set to 1

then the optimization will be enabled.

A system reboot is necessary for changes in this variable to take effect.

Miscellaneous Registry Variables

UseSoftwareCursor: If defined and set to 1 a software cursor is used instead of the

normal hardware cursor. This variable is not created by default.

A system reboot is necessary for changes in this variable to take effect.

ASUS 3DP-V500TX

Table of Contents