View Full Version : help on a bird rig
10-14-2002, 02:37 AM
ok here it goes. I've been trying write an expression based on the rotation of a main joint. the problem is that I want the affected joints to react one way such as when the main joint rotates from 60 to -60 the effected joint to rotate down and then switch to an oppisite rotation when it rotates from -60 to 60. Think feathers on a bird, when the wings rotate down the feathers encounter resistance And the opposite on the way up. I figured out how to do it based on time but that kind of limits what you can do with the rig. Any help would be great.
I'm not sure if this is what you're looking for, but I think this might work for ya.
I made 3 joints in a chain:
Then I made an if/else expression that controls the Z rotation of birdjoint2 based off of the Z rotation of birdjoint1:
if (birdjoint1.rotateZ>0)birdjoint2.rotateZ=birdjoint1.rotateZ *2;
The attached image are the results...
I hope this helps! :thumbsup:
also, i think u can use set driven key. u can control the way of move in graph editor.
10-15-2002, 07:08 PM
Ok let me try to explain this a little better. What i'm having a problem with is when the feathers rotate down (image A ) i have an expression that has them lag behind a bit. The problem that i encounter is when they reach the end of the flap (on the way down ) and start to rotate up it just does the same expression in reverse. What i would like to have them do is when it reaches the bottem of the flap i would like the feathers to revese their direction and look like they are encountering resitance. Image B shows what i want it to do when on the way up. Some people that i have talked to said that i might need to use a hermite curve to do what i am looking for...Thanks for all the help so far and i hope this clears it up a little.
10-15-2002, 07:09 PM
here is image B
So throw a math function in there to slow it down. Divide the rotation by a # on the way down and that should solve your problem...I think you're looking too much into this, this is a very easy thing to accomplish. Don't overdo it.
01-13-2006, 07:00 PM
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