Hi. While working on an animation of the internal workings of a Hammer Drill I have encountered problems with getting a nice fluid movement with ease ins and outs. I chose to do this animation Hammer Drill AS file
in AS to take advantage of bones and smooth movement however what a nightmare in trying to make the simplest of movements with the copper coloured hammer plunger hitting a striker part to create the hammer action.
Here is the original animation I need to replicate, done originally in Flash
Original Flash movie
When I try to add a little touch of ease in or out on the simple movement I seems to get a weird double movement in the motion. If I try to add ease ins manually I don't get the motion very smooth then I start moving into frame by frame adjustments.
Does any one know what I am doing wrong to smooth out this particular motion. Any suggestions would be most welcome.
Something so simple seems to be so difficult
Moderators: Víctor Paredes, Belgarath, slowtiger
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BunyanFilms
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A complex combined movement like your drill is never easy to set up. But you can save yourself from spending too much time by just remembering: less is more.
See the file at http://www.slowtiger.de/examples/drill.zip. I started with erasing every key save the first and last of the cycle. Then I created two keys at where the plunger hits the striker and gets hit by the striker again, and set the first to step since the plunger looses its momentum there. Then I created a last key 6 frames after the plunger housing starts moving, because the air inside first has to contract and then expand again, and adjusted its position so it just looked right to me. My keys were set to linear because the plunger, once pushed, has a continuous speed.
The main source of trouble in a machinery like this is that your loop point turns out to be in a totally wrong place in time. Best would be to have it where the part is totally at rest - but with many parts it gets impossible to have a loop point at the optimal position in time for all parts. I sometimes plan a scene like this 2 cycles long, with lots of copying during work, and decide later where the best position for the loop may be.
I don't claim to have awesome understanding of physics, but here it's a simple task of transferring momentum from one part to another, in different ways: slowly with air, fast with a hit.
BTW nice overall design!
See the file at http://www.slowtiger.de/examples/drill.zip. I started with erasing every key save the first and last of the cycle. Then I created two keys at where the plunger hits the striker and gets hit by the striker again, and set the first to step since the plunger looses its momentum there. Then I created a last key 6 frames after the plunger housing starts moving, because the air inside first has to contract and then expand again, and adjusted its position so it just looked right to me. My keys were set to linear because the plunger, once pushed, has a continuous speed.
The main source of trouble in a machinery like this is that your loop point turns out to be in a totally wrong place in time. Best would be to have it where the part is totally at rest - but with many parts it gets impossible to have a loop point at the optimal position in time for all parts. I sometimes plan a scene like this 2 cycles long, with lots of copying during work, and decide later where the best position for the loop may be.
I don't claim to have awesome understanding of physics, but here it's a simple task of transferring momentum from one part to another, in different ways: slowly with air, fast with a hit.
BTW nice overall design!
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BunyanFilms
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- Joined: Mon Aug 06, 2007 3:24 pm
- Location: Australia
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Thanks G and Slowtiger.
It's great of you Slowtiger to have a close look at the file. Even in you adjustments however I am still experiencing a slight incorrect movement due to the need to have linear key frames. I have certainly noticed that the ease-n or ease-out doesn't seem to work properly. For example if I add ease-in on the first key frame one would expect the motion to start off nice and slow then move into the next key frame. However every time on examining the onion skin (which doesn't allow enough frames) I find that the frames are easing out slightly resulting in the bad jerky movement. setting key frames to smooth doesn't help as one seems to get slight ease-ins and outs still. So I am forced to use linear and try to hand animate ease-ins and outs by eye and as you say G use the graph mode to try and smooth out the curve of motion. What a bad waste of time.
It's great of you Slowtiger to have a close look at the file. Even in you adjustments however I am still experiencing a slight incorrect movement due to the need to have linear key frames. I have certainly noticed that the ease-n or ease-out doesn't seem to work properly. For example if I add ease-in on the first key frame one would expect the motion to start off nice and slow then move into the next key frame. However every time on examining the onion skin (which doesn't allow enough frames) I find that the frames are easing out slightly resulting in the bad jerky movement. setting key frames to smooth doesn't help as one seems to get slight ease-ins and outs still. So I am forced to use linear and try to hand animate ease-ins and outs by eye and as you say G use the graph mode to try and smooth out the curve of motion. What a bad waste of time.
Well - I have a traditional frame-by-frame background, so I'm used to do everything by hand and judge the result by eye. Others who come from 3D seem to be comfortable with adjusting curves to get the desired result. With a totally mechanical movement like your drill this seems to be the best approach, however, the ease-in and out curves of AS are something I just don't use because I don't like the result.
If it's really necessary to have a perfect mechanical movement I'd draw the motion paths and all frame positions on paper, scan it in, and use this as a guide for placing my keys. This is still faster than fiddling with curves, at least for me.
As for a smooth result: IMO the only moment the movement may need adjustment would be around the cycle start/end. If it's good enough, leave it that way, it doesn't have to be perfect. Remember that your job is to show the general working of the drill, not a perfect physics simulation.
If it's really necessary to have a perfect mechanical movement I'd draw the motion paths and all frame positions on paper, scan it in, and use this as a guide for placing my keys. This is still faster than fiddling with curves, at least for me.
As for a smooth result: IMO the only moment the movement may need adjustment would be around the cycle start/end. If it's good enough, leave it that way, it doesn't have to be perfect. Remember that your job is to show the general working of the drill, not a perfect physics simulation.
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BunyanFilms
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Unfortunately it was the client that picked up on the slightly uneven movement. With more time spent on the movement it seems I haven an acceptable motion without too many hand frame. It took a lot of fiddling around. If the frame ease-in functions actually worked properly I am sure it would have been a much quicker job.