[vtkusers] vtk rendition is too dark with XFree86

[John Washbourne]

> "Chen, Elvis" <anisotropic7 at yahoo.ca>

> I managed to compile vtk4 on a FreeBSD 4.5  with
> XFree96 4.1.0.  The video card is Matrox G400.  With
> XF86's DRI support, the performance of OpenGL is
> actually not bad.
> 
> One minor problem is, vtk rendition is VERY dark when
> compared to vtk on, say, Solaris (Ultra 10 with
> Creator 3D).  I suspect it has something to do with
> gamma-correction being not turn-on.  Does anyone have
> an explaination/solution to this?

Elvis,

I recently switched from an ultra60 creator 3D to a intel xeon with a Matrox G450, and I found that 
I actually got the best performance -- judged subjectively by the "interactiveness" of a collection 
of 3D surfaces -- by specifically *not* loading DRI, GLcore, and glx. This may get the dri/openGL 
guys hot. I find that the colors and shading work quite well. Texture mapping is *way* better than 
for the creator 3d. The fact that I am using the xinerama extension may also be a consideration.

I tried a half dozen or so graphics cards over a week and settled on the G450 as the best for my 
needs. I did recompile everything that I could including XFree86, Mesa, geomview and VTK. On this 
dual intel 2 Ghz machine that took about 45 seconds ;)

NOTE: My decision was based on surface viz, your mileage may vary considerably if you are doing 
volume viz.

I can send along the entire config file if that would be useful. I did find that with dri on, the 
graphics were flakey and slower -- so slow it seemed almost to be software rendering. I probabaly 
have some things suboptimal but I spent the better part of a week fidgeting and this current config 
is stable and gives good performance for my (mostly surface vizualization/texture mapping) apps. If 
you discover some magic bullets, I would really appreciate it if you keep me informed.

Here is the output from xdpyinfo. I dont really know, but maybe the DGA (direct graphics) enables 
acceleration:

name of display:    :0.0
version number:    11.0
vendor string:    The XFree86 Project, Inc
vendor release number:    40200000
XFree86 version: 4.2.0
maximum request size:  4194300 bytes
motion buffer size:  256
bitmap unit, bit order, padding:    32, LSBFirst, 32
image byte order:    LSBFirst
number of supported pixmap formats:    7
supported pixmap formats:
     depth 1, bits_per_pixel 1, scanline_pad 32
     depth 4, bits_per_pixel 8, scanline_pad 32
     depth 8, bits_per_pixel 8, scanline_pad 32
     depth 15, bits_per_pixel 16, scanline_pad 32
     depth 16, bits_per_pixel 16, scanline_pad 32
     depth 24, bits_per_pixel 32, scanline_pad 32
     depth 32, bits_per_pixel 32, scanline_pad 32
keycode range:    minimum 8, maximum 255
focus:  window 0x600017, revert to Parent
number of extensions:    26
     BIG-REQUESTS
     DEC-XTRAP
     DPMS
     Extended-Visual-Information
     FontCache
     LBX
     MIT-SCREEN-SAVER
     MIT-SHM
     MIT-SUNDRY-NONSTANDARD
     RECORD
     RENDER
     SECURITY
     SHAPE
     SYNC
     TOG-CUP
     XC-APPGROUP
     XC-MISC
     XFree86-Bigfont
     XFree86-DGA
     XFree86-Misc
     XFree86-VidModeExtension
     XINERAMA
     XInputExtension
     XKEYBOARD
     XTEST
     XVideo
default screen number:    0
number of screens:    1

screen #0:
   dimensions:    3200x1200 pixels (804x302 millimeters)
   resolution:    101x101 dots per inch
   depths (1):    24
   root window id:    0x48
   depth of root window:    24 planes
   number of colormaps:    minimum 1, maximum 1
   default colormap:    0x20
   default number of colormap cells:    256
   preallocated pixels:    black 0, white 16777215
   options:    backing-store NO, save-unders NO
   largest cursor:    64x64
   current input event mask:    0x5a20bd
     KeyPressMask             ButtonPressMask          ButtonReleaseMask
     EnterWindowMask          LeaveWindowMask          PointerMotionHintMask
     ButtonMotionMask         StructureNotifyMask      SubstructureNotifyMask
     SubstructureRedirectMask PropertyChangeMask
   number of visuals:    1
   default visual id:  0x21
   visual:
     visual id:    0x21
     class:    TrueColor
     depth:    24 planes
     available colormap entries:    256 per subfield
     red, green, blue masks:    0xff0000, 0xff00, 0xff
     significant bits in color specification:    8 bits