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View Full Version : Need expression help > Wing flap cycle speed.



4dartist
06-20-2012, 02:34 PM
I have a small wing of a hummingbird that I need to animate. It has one main rotation of the wing, a morph for the shape of the wing, and a few bones that bend a degree or so each stroke.

Each part has 3 keys that just repeat.

I tried using wingcycle.rot(Time*(scaletime.pos(Time).x)).h

I would then use 1 as the value for 'scaletime', and then animate it to .9 or 1.1 to slowdown/speedup the flap speed, which works fine except for the transitions. As you move the time scale down or up it creates a lot of problems. The sine waves get cut and don't transition smoothly at all.

Is there a way I can access the channel at a variable for speed that wouldn't screw up the motion of the wing? Keep in mind the bones,morph,main rotation overlap a bit.
Thanks for any help, I'm going to be spending time trying to solve this so if I find anything I'll post.

4dartist
06-20-2012, 02:59 PM
I think I solved my own question. Sorry about that! Basically instead of using multiplication to scale time I used addition. Then, in my channel that represents time, if I want time to slow down I have to change the flat value to aim down a bit at a constant rate until I change the speed of time again. Basically, I don't change 1 to .9, I change 1 to decrease at a rate over time.

boneflap.rot(Time+(timechange.pos(Time).x)).h

Going to plug this all in and hope for the best. :)

SplineGod
06-20-2012, 05:03 PM
I believe relativity can also easiy do a speed control.
Another simple way is to mdscan the bird and then use dponts dpkits mdd playback node where you can control the playback speed of the mdd file with an envelope.