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Rotation momentum

Posted: Mon Jul 31, 2017 1:47 pm
by zoesan
I'm assembling a short clip based on wacky Japanese Ads I've seen, this one is beer, it has a rotating spoked wheel for Intro, as yet haven't managed to get the wheel to spin constantly, it seems to power down some frames before the 360 degrees cycle end, is it possible to have a wheel spin at a constant speed in the time frame. I've tried both looping in anime pro plus video Editor. Doesn't prevent the momentum of speed from slowing down, before picking up.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 1:54 pm
by slowtiger
Have a key at frame 1 and set its interpolation to linear.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 3:05 pm
by zoesan
Thanks slowtiger, but not happening, I've exported just to make sure and looped in Editor , the spoked 360 degree wheel spin slows down then picks up even on linear, I've tried the rest too.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 3:21 pm
by slowtiger
I don't know what you're doing to get this result.

I have only 2 keys. 1 at #1, the second at frame whatever, say #30. First key rotation value 0°. Second key rotation value 360°, one complete revolution. First key set to linear.

Now when I set the playback area from #1 to #29, I get a perfect rotation without any stops or slow downs.

To create a cycle, mind that position #30 optically is the same as position #1, so it must not be included twice.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 3:23 pm
by zoesan
Seems to work at an optimum at frame 60 in timeline on linear, I was looking at frame 150 in timeline, which so far results in a slowing down on approach to frame 150, so going to try 2 rotations to frame 120 next.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 5:05 pm
by slowtiger
You absolutely do something wrong, because I can get a smooth rotation for whatever frame interval I want.

Re: Rotation momentum

Posted: Mon Jul 31, 2017 8:20 pm
by Greenlaw
Yeah, linear should give you a constant rate.

BTW, the interpolation is applied for after the keyframe to the next keyframe, so the interpolation mode of the next keyframe doesn't affect the first one. Took me a while to really understand how that worked.

A good way to check (and learn) is to look at the curves in Motion Graph. This shows how the speed eases in and out at the key frames. If it's truly set to linear, it would show a straight line between keys with no curve.

Re: Rotation momentum

Posted: Wed Aug 02, 2017 5:33 am
by zoesan
Thanks for parties looking into this: I've been looking at a video posted by ShoNuff93 primarily for use of cutouts in anime, in it he's also tasked with turning wheels: he uses the rotation tool to turn the wheel slightly, then in the rotation box inserts -359 degrees, on frame 12 (his choice) sets cycle value 2, then on frame 1 sets linear, the result is a wheel that turns at a constant speed with no momentum drop, the technical rational for method is not one I can explain presently, but for my anime application it works.