Draw the images onto the back buffer of a doubled buffered OpenGL context and grab them from there.
Using the redbook and GLUT samples as a basis should be straightforward.
Look for glDrawBuffer and glReadBuffer calls.
thx 4 ur help, i did it but it’s desperatly slow due to the fact that my 3d card doesn’t have a hardware accumulation buffer, so I can’t go over 2 fps with only two samples to create the final image …
You are definently right about the Accumulation buffer. Any time you use that on a consumer based card (and even most high end workstation cards) be prepared for slowness. 3Dfx new voodoo 5500 has a different buffer called the T buffer. While I have never personally used it the powers that be say it is fast. This T buffer is basically a wimpy accumulation buffer that blends combines images as it goes rather than the more powerful accumulation stage that a true accumulation buffer offers. I know that there was a demo of Quake3 with motion blur on the Tbuffer so it must work.