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gbiv
08-13-2004, 10:05 AM
The answer to this may be obvious but I can't find it out "there" anywhere. Is it possible to access 3d textures when rendering in a pbuffer?
Basically I want to draw a quad that fills the pbuffer and have it textured w/ a slice of my 3d texture. Then I would like to update a slice of another 3d texture w/ the image in the pbuffer.
I have tried just a colored quad and then using that as my update to the 3d texture but that didn't work either.

In my display routine I basically activate my pbuffer, draw a quad and then specify the texCoords and verts for my quad. Then I try to
make a call to glCopyTexSubImage3D() w/the appropriate params. Later I just try to display the updated texture using a volume rendering technique. The volume rendering has worked up until I tried to use the above mentioned "texture update in pbuffer madness"!!!
:confused:

The only examples I've seen using pbuffers use 2d textures(i.e. glCopyTexSubImage2D()) so I'm thinking that is my problem. But maybe I need to specify certain attributes when I allocate my pbuffer or something else I may be over looking .
Thanks in advance for any help.

Sorry if this is a "newbie" question but I didn't get any responses w/ my post on the "newbie" board.
biv

V-man
08-17-2004, 09:14 AM
It should work fine. Make sure the p-buffers modelview and projection matrix are right, the 3D texture is accessible in the p-buffer (wglShareLists or create it in the p-buffer context).

You can use glReadPixels to view the contents of the p-buffer before calling glCopyTexSubImage3D()

gbiv
08-21-2004, 08:17 PM
thanks for the input. I finally go it to work! :D