How do i slow down animation properly?

Hello. I have short animation, which is 37 frames long, and only have two KeyFrames (at the Start and at an End). What i need is to make animation six time slower.

I tried to render it into video file, and then slow down with help of video editor, following this tutorial


But, unfortunately, after this action animation is no longer smooth. I can see how object “jump” from one static state to another.

I start to believe that my only option is to use animation slow down option in render tab, as deiscribed here


But it will increase render time drastically. I will have to render 222 images (37*6=222) instead of 37.

May be there are some approaches, which can help to slow down animation without rendering so much images?

The only way to slow an animation without incurring problems with it getting jumpy is to increase the number of frames rendered. It’s a simple matter of basic math. Video/film runs at a frame rate of 30 or 24 frames per second (fps) respectively (figures are common but not exclusive, btw). So every second of animation requires either 30 frames or 24 frames; either frame rate is quite acceptable. The lowest frame rate before starting to see problems is around 18fps. Lower than that and your eyes+mind can detect the shift from frame to frame, causing a strobing effect (jittery-looking motion).

Slowing things down means that the same action is spread over more seconds. So instead of 24 frames of action (1 second normally) you’ll need 48 frames = 2 seconds for the same action at half speed. Even slower rates use the same math. Three times slower = 3 x 24 = 72 frames for the same action that took 24 frames at “normal” speed.

It is possible to use a slower frame rate but the results are very limited and generally unsatisfactory, because any noticeable slowing will push the frame rate below 18 fps and that can affect the quality of the viewing.

Well said Chipmasque! :yes:

Or, thinking out of the box here, if the OP wants the whole action spread over 6 x 37 frames but still running at 24 fps…

What he could do is scale the F-curves in the Graph Editor by using 2D cursor positioned at frame 1 and then scale the F-curves in X only by a factor of 6 (key S X 6 return). I know you could just move the last keyframe, but that is not a practical idea if you have got 6 million keyframes in your animation, whereas scaling the F-curves would work in any scenario.

So either the frame rate is too slow for a smooth animation or OP has to render 222 frames to slow the animation by a factor of 6, one or t’other must be true. 4 frames per second is no good for a video IMHO so it must be render 222 frames.

What is the problem with rendering 222 frames - just leave it to cook while you go out for a beer or two. I once left a video cooking for two weeks while I went out for a beer or two, came home when it was finished absolutely p***** out of my skull :stuck_out_tongue:

Cheers, Clock. :eyebrowlift:

A problem I have had with scaling keyframes (and using the Time Remapping tool which does the same thing but leaves the keys in place) is that events that were timed to the frame can get jittered out of synch by the slowing process. So if you have any frame-critical synch points, like when constraints release or engage, etc., best to check them over thoroughly after slowing things down. This for more complex animations than a start and end frame, of course.

alive-one: 222 frames is not much at all. Under 10 seconds at 24 fps. Think about rendering out an entire 4 minute sequence, with various scenes that need some frame overlap, and of course may need re-rendering because “Oops, I didn’t see that!” and so on. That’s when you really start thinking about how to economize render times!

You haven’t actually said what you are animating. Is it a character, thing, etc. how many? How many actions do you have? If you have only one item and one action another alternative is to push your action down to the nla and use the scale factor in the playback to extend the range over the action. I don’t do fine film animation like chip or complex machine and sci fi stuff like clock, but I can tell you I use cycles and set a preview special render type for samples and light path for viewing the animation other than a playblast. I can get a 30,000 plus character to render in less than 2 seconds. So you render it until you fix all the mistakes and then just join Clock in the pub for a couple of weeks for the real thing. No problem! Let us know in detail what you are animating and supply a knocked down blend if you will and I’m sure you can get some great help!

Thank you chipmasque
I should have guessed that i must also increase FPS.
stilltrying My current animation is nothing special, just turntable of model. I’m new to animation and video editing, so sometimes i surprise myself how silly i can be in this field.

Thank you, guys. I decided to go brute force, and render 222 frames. Just left rendering for a night, and now everything is ready.
By the way is there a way to revert animation direction using video editor? For example i want my model to rotate clockwise, then counter clockwise. Surely there is no need to render conter clockwise part if i can simply add it as image sequence or video file, revert animation and render all together.

You can use your NLA. Push your action down. Say one action like this cube left to right keyframed from 1 to 10. Go to nla. push it down. Then select strip. Shift D for the duplicate. Add it on to the end or where ever. Then simply check the little reverse box in the active strip. That then reverses the action from right to left. You can do this a lot of ways, but I’m a big fan of NLA. You can also duplicate, move and scale -1 in dopesheet your keyframes. Use the F- curves and same thing. If your into python, use that to add a modifier. etc. Here’s a blend for you to look at with two keyframes, and probably other ways I haven’t thought of off the top of my head.

http://www.pasteall.org/blend/43120

Thank you for help!

Good for you! I’ve always been a fan of using a BFH* myself :wink:

Big F**ing Hammer!

In case you are interested here is final product :wink:

Turned out nice!