8 Replies Latest reply on Mar 19, 2012 8:16 AM by sosssa

    Timewarp / time remapping not running smoothly?

    sosssa

      Hi, I've got a problem with speed variation. I got 25fps exr footage rendered out of 3ds max which I want to add some speed variation to it in AE. The problem I'm facing is the footage stutters when using time remapping. basically what I was trying to do was to render the scene out very slow so I can crank it up  in AE. I've even tried different blending modes (pixel motion).

       

      Here is what happens when  trying to add some speed variation (when  slowing it down to the footage initial speed)

       

      1. time remapping causes stuttering.

      2. while timewarp gives strange interpolation errors (looks like blurring error) speed goes like 100-->150-->100 and errors occurs when going back to 100

       

      system:

      windows 7 64bit, i7 2600k, 3,4GhZ, 16GB RAM, Geforce GTX 580

      AE CS5.5

        • 1. Re: Timewarp / time remapping not running smoothly?
          TimeRemapper Level 4

          Can you post an example? Either video or project and source files?

          • 2. Re: Timewarp / time remapping not running smoothly?
            sosssa Level 1

            interpolation.jpg

             

            this  1 got timewarp ( and speed is cranked up, not slowed down)

            thats the interpolation frame

             

             

             

            interpolation2.jpg

             

            that's without timewarp

             

             

            time remapping brings same error but for  RPF files looks like it works for EXR

             

            looks like stuttering is not a problem anymore. i ran  another random speed variation test and it'd run smooth. Have to double check it with the intended speed variation

             

            I'll try to post a   similar project where file size is smaller

            • 3. Re: Timewarp / time remapping not running smoothly?
              Mylenium Most Valuable Participant

              Well, bad news for you: The effect is probably never gonna work like you want it to. The problem is that many of your pixels will in effect never change from frame to frame, at least not in the meaning that would be useful for the timewarp's internal analysis. It's inherent in the perspective you chose. such effects always need a minimum distance a pixel travels from frame to frame and using something that changes mostly in Z and consists of large uniformly colored areas is just not providing any distinct patterns. You really should do your retiming in MAX and just render it out again. I can't imagine such a simple shading taking longer than a few seconds per frame, which isn't more than you would get with timewarping it in AE - ojn the best of days, it tends to be slow as hog...

               

              Mylenium

              • 4. Re: Timewarp / time remapping not running smoothly?
                sosssa Level 1

                thanks for the information.

                unfortunately the animation is a little bit more complicated as it looks like and what you see is only the raw footage without any shaders, lights, shadows,.. included. 1 Frame to render takes approx. 1hr.

                 

                I use a path constraint for the train cars and  each train is rotated by hand around Z so they won't collide with the platform because path constraint don't give me nice results although using follow/bank.

                on top of that I even have a camera travelling which's suppose to adopt the speed variation from the cars and also a piece of paper that is keyframed and flies away when the cars pass by

                 

                Like I mention before i want to add speed variation so that would mean I have to rotate each car manually in Z from scratch and thats a lot of work. is their a workaround?

                • 5. Re: Timewarp / time remapping not running smoothly?
                  Mylenium Most Valuable Participant

                  Not using MAX I can only speculate, but such issues usually boil down to the underlying rig. I would probably rig it like a real train cart works - one wheel stand as the anchor, the other as the target constraint. By building a hierarchy you can then even build the whole train and it would follow the curvature almost perfectly. You then would only have to copy&paste the keyframes for the main bodies and figure out the timing so they are consistently spaced apart. Once you have that, you could apply a timewarp curve to the whole animation and everything should happen almost automatically. At least that's how I would approach it in Cinema 4D. Without knowing your exact setup of course it's hard to judge these things. Well, anyway, as a minor you should consider rendering a velocity pass also in MAX and using Twixtor Pro instead of Timewarp. that would resolve some of your issues already and you could further tweak by using masks. It's definitely worth looking into, if you can afford it..

                   

                  Mylenium

                  • 6. Re: Timewarp / time remapping not running smoothly?
                    sosssa Level 1

                    WOW, thx for the details. I was going to rig the train cart from scratch and doing it the same way.  I remember reading about rigging the wheels the way you've described it but I thought that'd be too much work. I'll give it a shot. I want to add some lens flare in AE why I need to plan everything accurately if I  don't wanna face the same problems later.

                     

                    So from what you're saying I should animate everything in a standard way and when I'm done add a timewarp ?

                    • 7. Re: Timewarp / time remapping not running smoothly?
                      Mylenium Most Valuable Participant

                      That's how I'd do it. I do a lot of technical animation (machinery and such) and the easiest way to start is to first create a perfectly working linear animation that plays infinitely and than based on that either create additional keyframes or remap it. This gives much more control over decelleration/ accelleration motion and otehr finesses...

                       

                      Mylenium

                      • 8. Re: Timewarp / time remapping not running smoothly?
                        sosssa Level 1

                        There's a topic on this with a nice movie tut further down how to rig it.