[vtkusers] Off screen rendering problem

[Jochen Schulz]

> One potential problem I can think of is mismatching libraries or
> include files. Make sure that the GL and OSMesa libraries are
> compatible (you can use ldd to check if they are shared). Also
> make sure that there is only one set of GL include files.

i checked both, so that was not the problem, but i searched onward in that 
direction. i was linking my program against GL and OSMesa. Linking to OSMesa 
alone or no of the 2 libraries at all solves the problem and the program is 
running just fine.. I must admit that i don't understand whats happening, but 
i am curious why it is so. Anyway, thank you Berk.

	regards
		Jochen

> On Fri, 2003-09-19 at 05:57, Jochen Schulz wrote:
> > Hello!
> >
> > i want to use offscreen-rendering with VTK and it was already
> > functioning when i upgraded from SuSE 7.2 to 8.2 .  That upgrade
> > unfortunately destroyed that functionality. I have VTK-4.2.2 and Mesa
> > 5.0-66. VTK is compiled with
> > VTK_OPENGL_HAS_OSMESA:BOOL=ON
> > and no mangled mesa.
> >
> > When i run my program i get the following error when trying to do
> > offscreen-rendering:
> >
> > Program received signal SIGSEGV, Segmentation fault.
> > 0x40a0b483 in OSMesaCreateContextExt () from
> > /usr/local/lib/vtk/libvtkRendering.so
> > (gdb) info thread
> > * 1 Thread 16384 (LWP 27887)  0x40a0b483 in OSMesaCreateContextExt ()
> > from /usr/local/lib/vtk/libvtkRendering.so
> > (gdb) backtrace
> > #0  0x40a0b483 in OSMesaCreateContextExt () from
> > /usr/local/lib/vtk/libvtkRendering.so
> > #1  0x40a0b280 in OSMesaCreateContext () from
> > /usr/local/lib/vtk/libvtkRendering.so
> > #2  0x40a068d0 in vtkXOpenGLRenderWindow::WindowInitialize() () from
> > /usr/local/lib/vtk/libvtkRendering.so
> > #3  0x40a09727 in vtkXOpenGLRenderWindow::SetOffScreenRendering(int) ()
> > from /usr/local/lib/vtk/libvtkRendering.so
> > #4  0x08063a39 in mvtkWindow::offscreenrender() (this=0x8213778) at
> > matvtk.cc:170
> > #5  0x08063289 in main (argc=1, argv=0xbffff264) at matvtktest.cc:88
> > #6  0x413608ae in __libc_start_main () from /lib/libc.so.6
> >
> > And i have no idea whats wrong. It would be very nice if someone could
> > somehow help me with this.
> >
> > 	regards
> > 		Jochen


**************************** 
Jochen Schulz 
Institute for Numerical and 
Applied Mathematics 
University of Goettingen 
Lotzestr. 16-18  
D-37083 Goettingen, Germany 
****************************