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Workflow and Compositional Question

Mar 30, 2013 4:09 PM

I have footage from 22 GoPro cameras, mp4, which I have imported natively into AE (11.02, OS 10.8.3 Mac 2.66mhz Quad Tower 16g of RAM) into 1 composition.  I plan to achieve the effect desired and then output a production codec, 422 prores for inclusion in my Premier project timeline.  Is this a valid workflow?


Next the compositional question:


Most of the 22 cameras (in an array) recorded two or more files of the 16 mintes of run-time, (there are 6 separate takes in that time period).  I pre-composed those footage files (after aligning a slate and for the seamless play of each layer) to neaten up and make more compact my AE timeline.


The effect I'm trying to achieve is a Time-Slice/Bullet Time where I can "cut" from one camera to the next all along the array, thereby freezing the action, but having the "camera" move around the subject - and then have the last layer/camera keep playing.  At the precise frame I want to freeze I put the opacity of each layer to 0 successively at the desired "freeze point" however in my ram preview only the first footage layer plays.  Without the opacity transformation on each layer I can achieve a rough version of what I'm trying to do by Solo'ing each individual layer and I cannot figure out why making each layer 0 opacity successively isn't working. 


Also once I completed all the Opacity transformations, the bottom layer should be visible 1 frame after the layer above it goes to O opacity, but it is in fact BLACK!  What the heck?


Do I need to slip each layer 1 frame forward in time so only 1 frame of each layer plays?  Again "turning on and off" each layer with Opacity?  I've found the answer to this question, at least for now.  Each successive clip gets trimmed to the desired frame, then slipped one frame in front of the layer above (save the top layer, which is trimmed to the frame).  This way the same frame is played over and over from each camera along the array.


Have I made a mistake by using the Pre-comps mixed with the 1-take footage?  In other words, my main comp now includes Pre-comps of the 2 files produced by most of the cameras, along with the original mp4 footage of those cameras which only recorded one file for the action.


And further; once I have the frames visible in the correct order would I Pre-compose again and apply a sfx like pixel motion to interpolate between the difference in angle/frame due to the difference in each camera's position?  Please suggest an alternative workflow or compositional layout!


I hope I've been clear, I'm here and willing to clarify if I've omitted any details.


I still would appreciate answers to the remaining issues if anyone has input for me.  The question now is: to time remap, or timewarp (which one?) before Pixel Motion - and is Pixel Motion best for frame interpolation to smooth it all out?




Thank you very much,
  • Currently Being Moderated
    Mar 30, 2013 6:21 PM   in reply to JesseHarris

    You specified a likely competent production codec, but what about your container?


    Having all these different files sounds like a prime candidate for gamma shift issues if you are using Quicktime for that container.


    That said, is this simply an issue with respect to alpha mattes?

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    Mar 31, 2013 4:19 AM   in reply to JesseHarris
    I plan to achieve the effect desired and then output a production codec, 422 prores for inclusion in my Premier project timeline.  Is this a valid workflow?


    once I have the frames visible in the correct order would I Pre-compose again and apply a sfx like pixel motion to interpolate between the difference in angle/frame due to the difference in each camera's position?

    So as to smooth motion on cuts you can do one of the following:

    1. Add an adjustment layer on top of all layers and apply Timewarp. Set Speed to 100, tick Enable Motion Blur checkbox, switch Shutter Control to Manual. Then keyframe Shutter Angle:

    - set first keyframe a couple of frames prior to the first 'transition' between camera angles, leave default value of 180;

    - set second keyframe in the next frame in the timeline and set value to the maximum - 360;

    - set third keyframe about one frame after the last 'transition' between camera angels, leave the maximum value of 360;

    - set last keyframe in the next frame, set value to 180.


    2. Smoother motion can be achieved via speeding things up and then slowing down in succession:

    - create a comp out of all your camera angles and trim them so that their In point starts at the very frame you want to get 'Bullet Time' effect out of which;

    - select all the layers and align their In point to '0' (press 'Home', then '[');

    - enable Time Remapping for each layer, add a keyframe right at the In point, go to e.g. 4 frames later in time, add another keyframe and set its value to the value of the previous one - now you have the 'Bullet Time' frame stretched four times;

    - distribute layers in time so that the second camera angle In point now was shifted to 4-th frame, third camera angle In point - to 8-th frame etc.;

    - add an adjustment layer, apply Timewarp and set Speed to 800 (or 400 if you want to slow down your 'Bullet Time' even 200% more);

    - add this composition into your master comp, move to appropriate frame in time and apply Timewarp on it. Set Speed to 50.


    Hope this helps.

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    Mar 31, 2013 7:54 AM   in reply to Fuzzy Barsik

    Let me just comment on one thing here:

    Also once I completed all the Opacity transformations, the bottom layer should be visible 1 frame after the layer above it goes to O opacity, but it is in fact BLACK!  What the heck?

    Here's the deal. The CTI rests at the start of a frame. This means if you look at the value for that frame you'll see the actual values for that frame. If you set the value to 0 then that's the value for the frame you are on, not the next frame. If you have a top layer at frame 105 set to 0 opacity and the layer directly below it also set to 0 then both frames are at 0. This makes sense.


    I think you are going about this in the wrong way. You're making a lot of work for yourself that you don't need to make. If you have all your layers synced and in the proper left to right order and you want to do a freeze at frame 200 then set the CTI to frame 200, split all of the layers, then move all of the new layers to the top of the comp and select them. This can be done with three keystrokes. Ctrl/Cmnd + A to select all layers, Ctrl/Cmnd+D to split all selected layers, Ctrl/Cmnd + ] to move all layers to the top.

    Now use Ctrl/Cmnd + right arrow to move one frame to the right and repeat the procedure. An easy way to mark these cut frames for easy selection would be to set a label group color. Select all layers above the initial split (your single frame layers and the layers above) and select Animation>Keyframe Assistant>Sequence Layers. Now the first layer above the single frame layers, snap the CTI to that layer by pressing the i key, set a timeline marker there, select all of the layers above the single frame layers and press Shift + Alt/Option + home to snap them to the first frame and then grab them and hold down the shift key to snap them to the CTI while dragging.


    That's it. It will take about 10 seconds. Now you can pre-compost that entire lot and set up any frame blending or time remapping you want in the precomp. 

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    Mar 31, 2013 8:52 PM   in reply to JesseHarris

    Hi Jesse,


    Re gamma shifts in QT, which seem highly likely to compound in an environment of 22 layers, I refer you to Todd's explicit advisories in this thread.


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    Mar 31, 2013 10:56 PM   in reply to Matt Dubuque

    I looked at your shot. Most of the problems are camera alignment. I've done this kind of thing before and it's important to establish a pivot point for the cameras so they are all focused at the same point in the scene. If you're going to pivot around the guy planting the kiss on the cheek then all cameras should be pointed at that point. Otherwise you are going to get some weird things happening in the move. Imaging framing the shot with a real time camera move and how you would want the framing set up. You have to match that.


    I would also do the 'bullet time' effect first and render that. Then I'd make the speed changes on the render. Putting the TimeWarp effect in an adjustment layer isn't the best idea. At least pre-compose your footage so timewarp has some adjicent frames to look at.


    As for the gamma problems, 1 layer or 1000, there's no build up. The gamma problems are only in the final render. If you set up an all QT workflow and set things up properly you can work without problems. I've been working on Macs and PC's rendering QT for more than 20 years. You just have to establish a color managed workflow and stay away from or work around known problems. Keeping your intermediate in a 10 bit or higher production codec is the first step in controlling the look of the final product.

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    Apr 1, 2013 1:29 AM   in reply to JesseHarris
    I'm guessing the artifacts are resulting from the mis-alignment of cameras and improper settings in Timewarp...

  may be this array just won't work because the difference in camera angle/frames is just too great.  If you have an opinion on this I'd love to hear it - however I do think I can get them into better alignment by using Scale and Position.


    I'd like to remove the ghosting and artifacts however, thoughts?

    Yup, that's because of cameras misalignment. Rick pretty much explained how it should be fixed at first place. Now you have to take the trouble to try to align them manually. You can use the sort of onion skinning while dabbling with positioning and scaling: with all your 'Bullet Time' layers stacked on top of each other temporarily disable eyeballs of 20 upper layers and decrease the opacity of the 21-st one to see the bottommost layer. When done with the 21-st layer, increase its opacity back to 100%, enable the eyeball of the 20-th layer, temporary decrease its opacity etc. etc.


    If you can afford Twixtor Pro, you can help it extrapolate pixels better with masking.


    Regard to applying Timewarp or Twixtor on an adjustment layer, for both effects it works just fine unless you want to apply the second instance of the effect. Twixtor doesn't like the latter, and if you add the second adjustment layer and apply the effect on it, you have a good chance to see a nice white solid. Hence, you have to precompose. Timewarp is not so picky.

    I took this to mean I should extend each camera footage in each successive layer by 4 frames, using your method of copying the first keyframe value to the second (and then applying Timewarp etc).  Was I correct?

    Hope, you got it right. But you don't actually need to extend every camera angle as a whole. You need just that very 'Bullet Time' frame, which you freeze, converting it from one frame to e.g. four in every camera angle, so as to give Timewarp or Twixtor more data to properly extrapolate pixels. Then you can trim all camera angles at this second keyframe and distribute layers via Keyframe Assistant -> Sequence Layers...(what you've done according to your screenshot).

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    Apr 1, 2013 3:16 PM   in reply to JesseHarris
    If I were to render that "bullet time" comp, I would render a 422PR QT correct?  Should I do that rather than Pre-compose?

    This question falls into the category, 'Whether transcoding yields better quality', on which we seems have completely opposite opinions with Rick. So as not to trust anyone, but rather know and judge on your own perform the following test:

    - set your project to 32-bit and linearise working space;

    - transcode your composition with distributed 'Bullet Time' frames, which is free from Timewarp, to OpenEXR with the compression method set to B44 32-bit float;

    - import OpenEXR sequence into the project, drop into the composition with distributed 'Bullet Time' frames and set blending mode to 'Difference' - you should get nice black solid without any artifacts;

    - apply Timewarp onto the layer out of OpenEXR sequence and copy and paste it onto the adjustment layer, which is accordingly below OpenEXR sequence and above all camera angles;

    - check if you see any artifacts instead of pure black solid. If you don't, transcoding doesn't yield any quality improvements. If you do, sorry Uncle Adobe, your strategy based upon native editing is a mistake.

    I am working in a Rec. 709 color space in AE and will render my (hopfully successful) "bullet time" sequence for insertion in my Premiere timeline.  Is this correct?

    PrPro is not colour-managed application and works in sRGB colour space. Since sRGB and Rec.709 are quite close, it doesn't hurt.

    Are there any morphing software you know of besides Twixtor?  Have you heard of Revision FX?  Some say it's better than Twixtor for this kind of application...

    Yes, RE: Flex maybe the right tool to do the job, 'cos you actually need to morph those 'Bullet Time' frames. No, I didn't use it by myself.

    wouldn't I need to match the closest frame, ie; most zoomed in?

    Yes, unless you're able to provide consistent zoom frame by frame.

    Are there any further settings in that initial Timewarp application which might help my issues?

    Yes, check out this Kronos User Guide. Although some settings are missing in the Timewarp, the basics are the same. By the way, Timewarp also can work with mattes. The difference with Twixtor is Timewarp can't recognise effects on the matte layer. Hence, if you create the matte with masks, Rotobrush etc. etc., you have to precompose.

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    Apr 2, 2013 4:00 AM   in reply to JesseHarris

    Re:Vision FX makes Twixtor


    The key to a good bullet time effect is not morphing between frames, it's camera alignment. You can actually pull off a fairly convincing bullet time effect with 2 or 3 cameras where you do a little distorting between the frames. It's kind of a 2.5D (camera mapping or Kid Stays in the Picture effect) technique combined with masking and some other tricks, but with 22 cameras and proper positioning you should be able to get a swing around the action that's perfectly clear and that's a nearly one second long. Pre-compose that or render the movie and apply Time Warp, Time remapping, Twixtor, or any of a dozen or so other time stretching techniques and you'll have your shot.


    If you want to focus on the guy planting the kiss and blur the background then you'll have to roto out that couple in each layer, fill the hole behind them by cloning, then add some directional blur to the background. All doable, but made easier by carefully setting up the shot in the first place.


    A few years ago I did a shot like this with 10 point and shoot cameras and a Sony Ex3 at each end of the arc. I simply put a tennis ball on a stick, set it at the center of rotation for the shot, visually lined up each camera, took a test frame to use for alignment in post showing the tennis ball, then we rehearsed and shot the shot. It worked perfectly the first time. The 10 frames for the move were stretched to 20 using Twixtor, did a little color correction and I was done. 

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    Apr 4, 2013 4:19 PM   in reply to JesseHarris

    So as to remove Audio from RAM preview you can either click Speaker icon (Mute Audio) in the Preview panel or disable Speaker icons for your layers. See this help section on previewing.

    I have not experimented with mattes yet... I guess there's not much to be done with the artifacts...


    P.P.S  Thank you so much for the Twixtor Pro tutorial you linked me to above, I watched it and am wondering if I can mask/matte as efficiently or sufficiently in Timewarp?

    Yep, mattes address this issue. Maybe not so efficiently, but definitely sufficiently. I was dabbling with image sequence (CinemaDNG sequence courtesy of John Brawley, Blackmagic Design) and Timewarp in the following way: I deleted every second frame in the sequence, stretched every frame rest to 8 frames, then consequently speeded up and slowed down with Timewarp with and without a matte. Here is the result (notice how the result is much smoother with no ugly artifacts on the billiard cue after applying a matte):

    Regarding the above, should Frame Blending be turned on in any of layers of this process?

    No, you are operating with a single frame in every layer, you don't need to blend it with itself.

    Now to the speed issue I have.  After viewing the RAM preview below, I'd like to slow down the "bullet time" section of the sequence.  Using your #2 method above could I extend each layer to 8 frames and apply Timewarp at Speed 200?  Or is there a better method of slowing the "swing" around the kiss?

    Try to dabble with. In my experience when stretching a frame too much Timewarp may get crazy. Check critical frames in between cuts, which Timewarp must reconstruct - whether they still look like stable frames or a bad TV.

    should I be working with any settings in the "intermediate" or first application of Timewarp?

    Here is when rendering intermediate may come in handy. Rick described perfect workflow here. Consequently, while you're dabbling with Timewarp settings, stretching or shrinking your frames etc. etc., preview in 1/4 or 1/2. When you're done with rough motion check and tested critical frames in full resolution, render out digital intermediate. Timewarp is time consuming, it is unwise to overload your rig, making it render two instances of the effect while dabbling with settings of just the second instance.


    Generally speaking, transcoding serves saving on time. Test your own machine so as to know when those savings are significant and, therefore, you'd rather render digital intermediate.


    Bear in mind, you don't have to always use that intermediate. You can set it as a proxy so as to be able to revert to your source files, if need be.

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    Apr 5, 2013 12:43 PM   in reply to JesseHarris
    please tell me, where did you draw the matte to help the pool cue distortion?

    Since Timewarp doesn't recognise any effects applied onto a layer, which is intended for a matte, you have to precompose it. In your case duplicate your sped up 'Bullet Frame' layer (which is your digital intermediate) and precompose the lower one. Open up that precomp and create a matte. Rotoscoping is probably not the most exciting thing in the world, but sometimes you have to deal with it.


    Don't think of a matte as of a single mask or a single Roto Brush effect, but rather split it into several parts: a mask for the guy right hand, a mask for the guy torso, a mask for the girl left hand etc. On a contrasted background Roto Brush tool could create a nice matte alone, but you are not so lucky. You may use Roto Brush to e.g. isolate main object and masks to isolate such moving things as hands. You may also try Mocha. See this Mocha tutorialon rotoscoping.

    I tried to ramp it back to real-time 50--->100 Speed after the bullet time is finished and it still plays at it's bullet time-comp 400 speed - what the heck?

    Do you remember that your layer (which is currently your intermediate) is a sped up version of your shot? When you're sliding from 50% to 100% speed on your adjustment layer, you're actually restoring the increased speed of previous Timewarp instance. What you need to do is just trim the tail of your intermediate at the point where your second 50% speed keyframe is set and add another one layer above, your last camera angle (source footage at normal speed), which head is trimmed to the 'Bullet Time' frame and snapped to that second 50% speed keyframe accordingly.

    Yes I am absolutely RAM previewing at 1/4 rez and also my Timeline viewer is set that way - BUT I must remember to set it to Full when rendering an intermediate or final out, correct?

    Nope. Setting display resolution doesn't affect rendering settings, which you control via Output Module and Render Settings options in the Render Queue panel.

    And by the way the I believe I have seen a major improvement in quality by Rendering to 422PR at every step.

    And which 'improvements' exactly were you able to see? 'Believing' is not wise. Test so as to know. Then we will be able to discuss what you've actually seen and whether those 'major improvements in quality' can be explained technical-wise.

    Any tips on Memory Allocation.

    See this FAQ entry.

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    Apr 5, 2013 10:58 PM   in reply to JesseHarris

    Here is how your project may look like.

    1. Precomp with your 'Bullet Time' frames:

    AE. Bullet Time. Frames.jpg


    2. Precomp within which you speed up your 'Bullet Time' frames. You can render a digital intermediate (DI) out of it:

    AE. Bullet Time. Speeding Up.jpg


    3. Precomp within which you create your matte (keep in mind, you replaced the 'Speeding Up' precomp in my screenshot with rendered DI):

    AE. Bullet Time. Matte.jpg


    4. Assembled Master comp (do not hesitate to exploit Timewarp Shutter as well):

    AE. Bullet Time. Final Movie.jpg


    5. The project flowchart (in case you can better understand all hierarchy relationships this way):

    AE. Bullet Time. Flowchart.jpg

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    Apr 10, 2013 2:32 PM   in reply to JesseHarris
    After Step 3 is when I should precomp the Speed Up footage and duplicate it - AND draw the masks on the lower layer correct?

    Not exactly. 'Speeding Up' composition remains 'Speeding Up' composition. You can render a digital intermediate out of it.


    As I already mentioned, you don't have to import it into the project and replace the 'Speeding Up' composition, you can select the 'Speeding Up' composition in the Project panel, right-click and choose Set Proxy -> File... Then locate your digital intermediate on your disk, select the file and click OK - the proxy is set, and the 'Speeding Up' composition is substituted with it inside all compositions, where it's nested. See this help section on proxies.


    You draw your masks not on the lower layer in the master comp. When you duplicated the 'Speeding Up' composition layer inside of the master comp, you precompose the lower layer, open up the newly created precomp ('Matte') and draw your masks there.

    I believe I had a problem over the weekend by drawing on the sped up footage/precomp - don't I need to draw the masks after the whole Master Comp has been slowed down here:  (in other words, I need the mask to correspond to the Timewarp 50 Speed frame rate, NOT the 400 speed Bullet Time DI, correct?)


    Shouldn't I be drawing the masks in Step 4 below?

    No, you shouldn't. You need to help Timewarp slow down your 'Speeding Up' composition. That means both 'Speeding Up' and "Matte' must be of exactly the same speed, i.e. 400% of the stretched 'Bullet Time' frames. However, since Timewarp does not recognise any effects on a layer, which is used as a matte, you have to precompose the lower 'Speeding Up' layer into 'Matte' and draw your masks there so as to get 'rendered' alpha channel inside your master comp.

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    Apr 10, 2013 11:55 PM   in reply to JesseHarris
    It looks to me like BOTH items are precomped here in your Master Comp - The Movie.  I know you've spelled out the steps very clearly, but I'm missing something here...

    Yes, in my master comp they are both precomps. And because of two reasons:

    1. I don't see the use of rendering digital intermediate for the sake of rendering digital intermediate (transcoding).

    2. If I need to use digital intermediate so as to save on further render time, I don't import it into my project and replace my precomps all over the project, I simply set the intermediate as a proxy to according comp - very handy.

    Into my Master comp, duplicate it and draw masks on the lower one.... but evidently this is incorrect...


    Where is this "Matte" comp coming from?!  From your instructions it is a duplicate of the Bullet Time + 400 Speed DI's  How did it get in a separate comp by itself?

    Precompose your lower ' Comp 1' once again, open up that newly created precomp and draw your masks there.

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    Apr 11, 2013 12:08 PM   in reply to JesseHarris
    Also I believe Rick

    That's your decision: if you want to know, you test and ask questions; if you want to believe, you believe. this now convoluted thread (my fault, no one else's)...

    Not sure I follow you... Asking questions is what this Forum is for...

    I Precompsed the lower duplicate of Comp 1 (although I'm not sure why that was necessary as it was already a Precomp)...

    Have you ever seen this?

    Same for precompositions. You may use whatever complex nesting hierarchy in your project. Forget it is a precomp for now, it's just a layer, which looks like a comp, and which you need to nest one more time.

    How do I get that Precomp into my Master Comp as you've done?

    If you select your lower ' Comp 1' layer in your master comp and precompose it (Ctrl/Cmd+Shift+C), that precomposition immediately replaces ' Comp 1' layer in your master comp, no extra steps needed to get it into. Tick 'Open New Composition' in Pre-compose dialog box, and you are inside your newly created 'Matte' precomp. Draw masks on your ' Comp 1' layer and just switch back to the master comp.

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    Apr 11, 2013 1:53 PM   in reply to JesseHarris
    If I Copy and Paste them from the separate Matte Comp into the Matte Comp precomp in the Master Comp, of course the timing is off because of the top Timewarp 50 Speed Adj... Now if I re-time the masks in the Master Comp, making sure Add is chosen, I think I can make it work.

    Leaving aside your 'off course the timening is off' ('cos both your 'Matte Comp' and upper ' Comp 1' MUST BE of exactly the same time), nope, you can't. Timewarp will ignore masks drawn in a layer inside the same composition. That's why you have to hide your smaller Matryoshka, ' Comp 1', into a bigger one, 'Matte Comp'.

    Another separate question - and if you'd like me to start another thread I'll be happy to do that.  I'm working in a 29.97 Project/Timeline in AE for these sequences, as the GoPro's were set to that frame rate.  However I'll be dropping these Production Codec renders out of AE into a 23.976 Premiere Pro project/timeline. I think I have problems... Should I be reintrepting this GoPro footage to 23.976 in AE first?  I tried a putting a 422PR test render into PPro and it looks slightly jerky, shouldn't it be slowed down slightly in the 23.976 Timeline?

    That's definitely for a separate thread. The short answer: it's easier to go from 23.976 fps to 29.97 fps than in reverse. And if you mix different resolutions and different frame rates, edit in smallest resolution and fastest frame rate (i.e. if you shoot partly in 1920 x 1080 and partly in 1280 x 720, edit in 1280 x 720; if you shoot partly in 23.976 fps and partly in 29.97 fps, edit in 29.97 fps).

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