11 Replies Latest reply on Aug 27, 2008 9:14 AM by Mylenium

    OpenGL rendering problem

      Heya everyone,

      I'm having a problem rendering out a project of mine. When I don't have "Use OpenGl Renderer" enabled in my render settings, my project renders out just fine. When I have it enabled, it'll render about a quarter of the way and crash the program.

      An easy fix would be to leave it unchecked, but I noticed that without it my render takes 2 1/2 hours to finish. When it's checked, the estimated time is 24 minutes - it absolutely CHEWS through the project. Unfortunately, crashing is inevitable.

      Is there any way to fix this? I would REALLY like to have the extra bonus of the OpenGL renderer going through my projects at five times the speed.

      BTW - I have a Dual quad core Xeon and my vid card is an HD4850.
        • 1. Re: OpenGL rendering problem
          Mylenium Most Valuable Participant
          Nope, I don't think so. Looks like it isn't flushing the graphics card's buffers correctly and thus it causes the crash at some point. The card being so new means you will most likely have to find a way of your own to deal with these issues - it wasn't around when CS3 was developed, so it's natural there may be issues of unknown type and origin. I would think that some tweaking of the card's OpenGL parameters in concert with AE's own settings might improve matters slightly, but no guarantees...

          Mylenium
          • 2. Re: OpenGL rendering problem
            Level 1
            Quick update - I might've found a fix! I read about the Secret option list in Preferences and set the Purge setting to 20 frames - no crashes yet!

            Now if only I could get the multiprocessing bug to work... setting the MP to a different value doesn't seem to work for me. AE still closes all of the processes.
            • 3. Re: OpenGL rendering problem
              Navarro Parker Level 3
              I don't believe you can multiprocess AND use OpenGL for your final renders. (Since you only have one GPU)
              • 4. Re: OpenGL rendering problem
                Todd_Kopriva Level 8
                > I don't believe you can multiprocess AND use OpenGL for
                > your final renders. (Since you only have one GPU)

                Navarro is right.

                from the "Render with OpenGL" page of After Effects CS3 Help on the Web:

                "You cannot use the Render Multiple Frames Simultaneously multiprocessing feature while also using OpenGL to render RAM previews or render for final output. The Render Multiple Frames Simultaneously feature works by using background processes on multiple CPU processor cores to render frames. OpenGL processing uses the GPU."
                • 5. Re: OpenGL rendering problem
                  Mylenium Most Valuable Participant
                  I love it when Todd quotes the help files... ;-) To elaborate a bit further: if you wanted to use OpenGL combined with MP, you'd have to have at least just half the number of graphics cards (or more precisely, isolated display buffer devices) as you have cores in your system plus the main display adapter, so you could use some magic on them to render in parallel. As it stands, you don't get that anywhere to buy, not even with Quad SLI setups, so it's a very theoretical scenario. It also would require to treat those additional cards completely differently, so they are mostly ignored by the operating system, but then controlled directly by the host app when needed. This and a number of other things make this a major undertaking on all ends and because of that the likelihood of it ever coming to pass is extremely low. In the short run, I think we'll have to make do with the current model and later on, as these things evolve, we possibly could hope to see a more generalized GPU acceleration by ways of CUDA, OpenCL and the like. That is - if the industry partners involved can settle on standardization and get everyone on board to make it feasible for software vendors to invest the effort and time. Still, even that will take at least 2 years from now...

                  Mylenium
                  • 6. Re: OpenGL rendering problem
                    Todd_Kopriva Level 8
                    > I love it when Todd quotes the help files...

                    Sarcasm?

                    Now I'll spend my entire morning wondering.

                    FWIW, my main goal in pointing people to Help on this particular forum is that I want to show people where they can find the answers to some of the common questions. This frees the experts on this forum up to answer the more difficult, odd, and interesting questions.
                    • 7. Re: OpenGL rendering problem
                      Mylenium Most Valuable Participant
                      >Sarcasm?

                      No, true admiration. Unearthing these bits of info from the depths of the database surely counts for something. Most of the time I'd simply be too lazy to even go looking for this kind of stuff in the online help.

                      Mylenium
                      • 8. Re: OpenGL rendering problem
                        Level 1
                        Where is this SECRET setting? (PURGE)
                        My NVIDIA FX 5600 --it is NOT new! -- also crashes.
                        • 9. Re: OpenGL rendering problem
                          Mylenium Most Valuable Participant
                          Hold down Alt while entering the preferences menu. Then an additional entry in the options list should become available. You can also edit this parameter directly in the prefs file with a text editor.

                          Mylenium
                          • 10. Re: OpenGL rendering problem
                            (Steve_Patterson) Level 1
                            I think Mylenium meant to say hold down "shift" while accessing the preferences.
                            • 11. Re: OpenGL rendering problem
                              Mylenium Most Valuable Participant
                              Indeed. ;-)

                              Mylenium