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Richard Hebert
12-10-2009, 03:16 PM
I've got a landing gear that I'm using for learning IK. I'm needing the lower gear to move only on its Y axis and not rotate (it's a hydraulic cylinder). I've tried limiting rotation values in the motion options to no avail. I know this can be done but not sure how. I've tweaked and clicked every button combo I could think of to cure the problem. Any thoughts on this would be readily accepted. Thanks in advance.

Richard

RudySchneider
12-10-2009, 07:20 PM
You might try to find the Hydraulic Cylinder Tut by Kurt Harris, or consider looking over this thread:

http://www.newtek.com/forums/showthread.php?t=53505&highlight=piston

It helped me with a similar problem.

ramccombe
12-12-2009, 10:42 AM
I've got a landing gear that I'm using for learning IK. I'm needing the lower gear to move only on its Y axis and not rotate (it's a hydraulic cylinder). I've tried limiting rotation values in the motion options to no avail. I know this can be done but not sure how. I've tweaked and clicked every button combo I could think of to cure the problem. Any thoughts on this would be readily accepted. Thanks in advance.

Richard

Hi Richard, I took a shot at your problem and I think this is close. The one problem I haven't figured out is how to keep the root from moving. I hope this helps.:thumbsup:

ramccombe
12-12-2009, 11:11 AM
I made a change to stop the scissor IK at the scissor instead of the root. :thumbsup:

ramccombe
12-12-2009, 11:27 AM
I added a ROOT_NULL so you can move and rotate the whole rig.:thumbsup:

Richard Hebert
12-12-2009, 09:25 PM
Thanks for the assistance. Sorry for the late reply, seems that I forgot to subscribe to the thread. There's something really funky going on with the parenting of the smaller pneumatic pistons attaching the door to the landing gear. Here's the scenario... I moved the model's piston layers in modeler to 0,0,0 and faced them down the positive Z axis. Brought the model into Layout and moved all the pistons into place and parented them to the appropriate geometry. Finally, I had the pneumatic tubes 'look' at each other. Everything worked fine when the door was closed. All of the pistons behaved normally and all of the pivot points lined up fine with the model. When I closed the scene down and reopened it, all of the pistons were dislocated far from their pivot points and a message appeared saying "Cyclic item dependency: gear_rig_test_002 etc. Can't find anything in the manual to figure this one out. Any thoughts?

Richard

Richard Hebert
12-12-2009, 09:57 PM
Thanks again, ramccombe. The rig is very nice indeed! It will take me some time to digest just how everything works.

Richard

ramccombe
12-12-2009, 10:21 PM
Hi Richard, the only things I can think of are 1 when you moved the model in modeler did you also reposition all the pivot points? and 2 the rig is built in layout which means you will want to mirror the whole rig in layout. To be honest I'm actually still pretty new to this rigging thing. Believe me I spent a while figuring this out but I just like a challenge. You might want to experiment with mirroring the rig with the scene I sent. I think you have to mirror the IK chains 1 by 1 not sure. Mirror the model that I sent in modeler and make sure the pivot points are in the correct places. Hope this helps.:thumbsup:

ramccombe
12-12-2009, 10:28 PM
Told you I was new to this, I just found out Mirror Hierarchy in Layout is only for bones not IK chains. Well maybe the other info helps.

Richard Hebert
12-13-2009, 05:26 AM
I think I forgot to reposition the pivots in modeler. Let me try that and see if it works.

Richard

Richard Hebert
12-13-2009, 06:18 AM
OK, that was the problem. I had to reposition the pivots in modeler. Good call!

Richard

ramccombe
12-13-2009, 09:34 AM
Glad to hear it and glad I could help. I have to thank you because I now have a little better understanding of setting up rigs. I probably wouldn't have pursued this type of rig on my own. Mind you I still have a lot to learn but helping you helped me. Now let's see your end result.:D