September 25, 2008

Attendees: tef, Tom, Elaine, Greg, Eric, Scooter, Conrad

New Action Items

• None

Action Items from previous meetings

• Al will decommission SGI after the next Chimera production release
• Al will install stereo-capable workstation to replace SGI before decommissioning SGIs
• tef will contact Adobe for more information about embedding 3d graphics in PDF documents
• Greg will implement OpenGL-feature-usage interface

Minutes

0. Review Action Items
   1. Eric received e-mail from Baker that it's okay for SGI to go away. There was no answer from Gough. Consensus is that SGIs can be turned off any time, after making one last "checkpoint" tape backup.
   2. Tom mentioned that he was asked to comment on 3D figures in PDF in upcoming article.
   3. For stereo-capable workstation, Al will wipe Michiko's old machine, install a Quadro 980 card, and reinstall OS.
   4. Conrad has fixed daily build script to copy app to desktop machines. Build trees are not copied currently due to lack of demand.
   5. Greg had handouts for an OpenGL panel prototype. The prototype placed "Enabled features" (queried OpenGL features) in the left-hand column, and "Quality of implementation" (workarounds) in the right-hand column. The left-hand column by default is all (or at least mostly) checked, while the right-hand column by default is all (or mostly) unchecked. Tom pointed out that the two-column division is artificial and confusing. Tom suggested that the check buttons should have the same sense in both columns, ie an OpenGL feature (or set of features) is in use when a button is checked; that way, clearing all the buttons means using the minimal set of OpenGL features with all workarounds enabled. Greg pointed out that the workarounds were really for specific graphics environments and were not intended for general use; in particular, the stereo workarounds can actually have adverse effects on many platforms when turned on unnecessarily. Scooter pointed out that we have never tested Chimera with all workarounds enabled, and that we need to test such a configuration thoroughly to make sure it is really minimizing OpenGL usage and not introducing problems.

1. OpenGL panel
   • Consensus is that we should remove the stereo options from the panel (or perhaps place them in a separate tab in the panel), put the remaining features and workarounds into a single group (by rewording the workaround descriptions), and add a "Disable All" button to uncheck all buttons. By vote, the OpenGL panel should go into the "Utilities" tool category rather than in Preferences panel. (The pros for putting it in preferences is that these are configuration options; the cons is that we are really using them for debugging, not tuning.) The title for the tool should include the word "Debug" or something equally scary.
   • Also by vote, we will (for now) use a separate OpenGL configuration file rather than storing the options in the preferences file. (The pro for putting options in preferences file is that there is only one file to carry around; the con is that more code needs to be written and reorganized to make that work.)
   • Finally, we could not agree on what should happen when a saved OpenGL configuration (which includes hardware/software version identifiers) does not match the current hardware (eg driver was updated or graphics card replaced). Tom and tef want to display a warning and then use the saved configuration; Greg and Conrad want to display a warning and then ignore the saved configuration. The pro for using non-matching saved configurations is that driver updates typically do not fix observed OpenGL bugs; the con is that one would not take advantage if the driver _does_ fix problems, and that one would need to ignore the configuration any way if the platform or graphics card changed. This topic will be an agenda item for next time.

Meeting ended before items below were discussed.

• Schedule Chimera library course for Winter quarter (Scooter)
• Discuss test lab, viz room and public cubicle setup (Conrad)
• Continue evaluation of features to remove or improve (All)