VMD-L Mailing List

From: Alan Wilter Sousa da Silva (alan_at_lac.inpe.br)
Date: Tue Sep 30 2003 - 09:30:48 CDT

Hi List!

Hi John Stone!

About my problem in getting messing images with snapshot I have to say
that I found out a solution. It's basically what you point out.

Changing the antialising nvidia driver parameter does the job.
For my Gforce2 I have to do:

export __GL_FSAA_MODE=3

then
vmd

Surely I can insert that line in vmd startup script, right?
BTW, VMD has a proper option for changing antialising?

Thank you very much.

PS: Follows text grabbed from nvidia docs.

(app-e) APPENDIX E: OPENGL ENVIRONMENT VARIABLE SETTINGS
__________________________________________________________________________

FULL SCENE ANTI-ALIASING

Anti-aliasing is a technique used to smooth the edges of objects in a
scene to reduce the jagged "stairstep" effect that sometimes appears.
Full scene anti-aliasing is supported on GeForce or newer hardware.
By setting the appropriate environment variable, you can enable full
scene anti-aliasing in any OpenGL application on these GPUs.

Several anti-aliasing methods are available and you can select between
them by setting the __GL_FSAA_MODE environment variable appropriately.
Note that increasing the number of samples taken during FSAA rendering
may decrease performance.

The following tables describe the possible values for __GL_FSAA_MODE
and their effect on various NVIDIA GPUs.

__GL_FSAA_MODE GeForce, GeForce2, Quadro, and Quadro2 Pro
-----------------------------------------------------------------------
  0 FSAA disabled
  1 FSAA disabled
  2 FSAA disabled
  3 1.5 x 1.5 Supersampling
  4 2 x 2 Supersampling
  5 FSAA disabled

__GL_FSAA_MODE GeForce4 MX, GeForce4 4xx Go, Quadro4 380,550,580 XGL,
                and Quadro4 NVS
-----------------------------------------------------------------------
  0 FSAA disabled
  1 2x Bilinear Multisampling
  2 2x Quincunx Multisampling
  3 FSAA disabled
  4 2 x 2 Supersampling
  5 FSAA disabled

__GL_FSAA_MODE GeForce3, Quadro DCC, GeForce4 Ti, GeForce4 4200 Go,
                and Quadro4 700,750,780,900,980 XGL
-----------------------------------------------------------------------
  0 FSAA disabled
  1 2x Bilinear Multisampling
  2 2x Quincunx Multisampling
  3 FSAA disabled
  4 4x Bilinear Multisampling
  5 4x Gaussian Multisampling

__GL_FSAA_MODE GeForce FX, Quadro FX
-----------------------------------------------------------------------
  0 FSAA disabled
  1 2x Bilinear Multisampling
  2 2x Quincunx Multisampling
  3 FSAA disabled
  4 4x Bilinear Multisampling
  5 4x Gaussian Multisampling

NOTE: 2x Bilinear Multisampling by 4x Supersampling and 4x Bilinear
Multisampling by 4x Supersampling are not available when using UBB.

--------------------------
Alan Wilter Sousa da Silva
--------------------------
B.Sc. - Dep. Física - UFPA
M.Sc. - Dep. Física - PUC/RJ
D.Sc. - IBCCF/UFRJ
Bolsista Pesquisador LAC-INPE
São José dos Campos (SP), Brasil
www.lac.inpe.br/~alan