[vtkusers] Offscreen rendering under Unix with OpenGL?

[John Norris]

Hi,

My app gives the user the ability to make movies using an offscreen render
window.  With VTK 3.2, I could use vtkOpenGLOffscreenRenderWindow from
http://zeus.ncsa.uiuc.edu/~jshalf/VTK/vtkOffScreen/
but this code doesn't work with VTK 4.1; too much has changed.  I've tried
writing my own vtkOffscreenXOpenGLRenderWindow, using vtkXOpenGLRenderWindow
as the starting point and changing it to use a GLXPixmap, using
vtkOpenGLOffscreenRenderWindow as a guide (I don't try to do anything with
pbuffers).  The code doesn't crash, but I don't get any images, either.  I'm
not terribly familiar with programming directly with X or GLX, so I'm not
sure what I'm doing wrong.  Any suggestions/ideas?

You can look at the source code for vtkOffscreenXOpenGLRenderWindow at

http://www.csar.uiuc.edu/~jnorris/code/vtkOffscreenXOpenGLRenderWindow.h
http://www.csar.uiuc.edu/~jnorris/code/vtkOffscreenXOpenGLRenderWindow.cxx

For the record, using OSMesa is not really an option.

Thanks,
John
-- 
John Norris
Research Programmer
Center for Simulation of Advanced Rockets
http://www.uiuc.edu/ph/www/jnorris