[Chimera-users] OS X aqua version

[Greg Couch]

On Sun, 1 Jun 2008, Glenn Millhauser wrote:

> Hi Folks,
>    I just saw the mac aqua version at the download site and decided
> to give it a try.  Layout looks terrific.  However, it seems to move
> molecules much more slowly than the X windows version.  I'm running on
> a macbook (intel) with inherent limited graphics capabilities, so
> perhaps that's the problem.  Any comments?

So it turns out this is due to chimera asking the graphics to multisample 
each pixel to improve the image quality (it reduces the jagged edge 
effect, especially noticable on ribbons and surfaces).  This was not
implemented in Apple's X11 OpenGL, so we didn't have this problem before.

Here are Chimera Aqua benchmark results for a MacBook 2Ghz Core Duo with
Intel GMA 650 graphics running OS X 10.4.11:

 	Volume benchmark scores
 	 surface    mesh  contour  solid  recolor
 	     1      16     157       1       3
 	Molecule 1f4h (33805 atoms):
 	Null	Wire	Stick	BStick	Ribbon	Sphere	Ops
 	29.8	7.5	1.6	1.4	4.3	0.3	26.3

And without multisampling:

 	Volume benchmark scores
 	 surface    mesh  contour  solid  recolor
 	    128     139     156     138      88
 	Molecule 1f4h (33805 atoms):
 	Null	Wire	Stick	BStick	Ribbon	Sphere	Ops
 	72.2	41.8	14.1	14.1	26.5	10.2	26.7

So without multisampling, it's 6-100 times faster!  Unfortunately,
there's no way to give command line arguments when clicking on the
chimera icon, so to turn off multisampling for now, you would need to
start up a Terminal and type:

     ./Desktop/Chimera.app/Contents/Resources/bin/chimera --nomultisample

That's assuming the Chimera.app is on your personal desktop.  Or you
could edit the Chimera.app/Contents/Resources/share/chimeraInit.py file
so that nomultisample defaults to True instead of False on line 52.

We will figure out an alternative solution that by default doesn't ask
for multisampling for Intel motherboard graphics (same issue exists with
Microsoft Windows).

 	Greg Couch
 	UCSF Computer Graphics Lab