# Application Sharing of 3D OpenGL Graphics Applications

SunForum 3D provides users with accelerated high performance sharing of 3D OpenGL applications. The SunForum 3D conference manager contains controls for displaying 3D applications.

SunForum 3D will interoperate with earlier versions of SunForum as well as other H.323/T.120 based conferencing applications, but accelerated sharing will be available only from a SunForum 3D host sharing the application to the SunForum 3D participant(s) in the conference.

When SunForum 3D sharing is enabled, the OpenGL image data is grabbed, compressed, and sent to all participants in a conference over a private channel. The participants in turn receive the data, decompress it, and display the image. Various options are available to configure this pipeline that displays the 3D application. You can change some of these options dynamically (from the SunForum 3D GUI) while a conference or sharing is in progress. You set other options in a SunForum 3D system or user specific configuration file.

There might be a noticeable slowdown in the frame rate of the 3D OpenGL application being shared. This is expected behavior, since each frame needs to be grabbed, compressed, sent to all receivers, decompressed, and displayed. You can control this behavior and performance using the SunForum 3D conference manager interface 3D controls.

Refer to the SunForum 3D Software User's Guide for more information, including OpenGL application requirements.

## SunForum 3D Operation Control Descriptions

#### The 3D toggle button

When this button is turned on (checked), the SunForum 3D application sharing is enabled. When it is turned off (unchecked), the SunForum 3D application sharing is disabled. In the latter case, application sharing still takes place (as it does with SunForum). However, there is a significant degradation in the frame rate and the integrity of frames on the viewers as compared to the SunForum 3D application sharing mode.

Toggle this button off when there are non-SunForum 3D compliant parties in a conference who need to see the application at some moments during the conference. Turning the 3D application sharing toggle button off impairs performance, but it makes the frames visible to the non-SunForum 3D nodes.

#### Higher speed - Better quality slider

Frames are compressed at one end and decompressed at the other. The CODECs used for compression/decompression are discussed in Setting Parameters for 3D Application Sharing, but some of the CODECs allow for a parameter which balances the compression ratio versus the loss in image detail. If the currently selected CODEC has such a parameter, then the slider will be enabled, otherwise the slider is inactive.

Depending on the CODEC, on the size of the frames, CPU processing capabilities, and the available bandwidth, the effects of moving the slider might or might not be visible. It is best for users to set the slider in the middle, and then adjust it left or right depending on the performance, image quality, and other needs.

NOTE that the slider is effective for the sending side of the application (application sharing host) only.

#### Allow frame skip (send)

Frames are grabbed, compressed, sent over the network, decompressed, and displayed. By default (when this button is not checked), every frame generated on the host is sent and seen on all other SunForum 3D participants in the conference. Selecting "Allow frame skip (send)" slows down the application being shared to whatever the bottleneck might be (typically, either the compression or the network congestion).

When you select "Allow frame skip (send)," SunForum 3D is allowed to skip the transmission of some/certain frames in the application (if the rest of the pipeline is busy) so that the OpenGL application is not slowed down as much.

Setting this toggle on a viewer system will have no effect on the application sharing host, that is, this toggle is effective only for the application sharing host.

NOTE that this button has an effect only on the SunForum 3D hosting the shared application.

#### Allow frame skip (rec)

This toggle button is the equivalent of the frame skip toggle button on the receiving end. By default (when this button is not checked), every frame received is decompressed and displayed.

When you select the "Allow frame skip (rec)," SunForum 3D skips the display of some frames so as to show the most recent frame (generated at the host) sooner.

For example, if the system is a low end system and decoding and/or displaying are relatively slow compared to the other systems in a conference, then the low end system would, in principle, slow down the frame rate for everybody in the conference. In this case, the user at the low end system could press and select this toggle button, thus enabling frame skipping and not slowing down the host and the others in the conference as much.

Setting this toggle on a viewer system will have no effect on the application sharing host, that is, this toggle is effective only for the receiving system.

### SunForum 3D Configuration Files

The entries in the /opt/SUNWsf3d/config/system-config configuration file contain various parameters that control the behavior of the 3D application sharing. This file can be edited, although you need to be superuser to edit the file. The parameters are explained in the configuration file.

A user editable copy of this file exists in $HOME/.sunforum/.sf3d-user-config. If this file does not exist, make a copy of the system-config file. This file will also be updated by SunForum 3D, depending on GUI selections made by the user while running SunForum 3D.

NOTE that when entries are in both .sf3d-user-config and system-config files, then the values of the parameters in .sf3d-user-config take precedence over those in system-config.

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