I am pulling my hair out trying to reposition a landing gear leg on a spacecraft.  So before I move the leg and with the green joint editor origins "on"  - the axis are lined up so that when I retract the legs on the x axis they bend in the right direction, the axis bends - all is good and the origins are oriented properly to the back end of the leg where the joint is. 

When I move the leg a few degrees over and rotate it along the y axis- retract still works but now the leg bends on the same X axis but "TWISTS" around etc. because I've rotated the y axis a bit to reorient the leg. It is not staying straight and is bending on two axises.

So-what would be the steps in getting the center points on the origin lined to the leg again AND have it bend correctly - i.e. stay perpendicular to the bottom the of craft as originally created?

I've dinked around with the dials - lined the green cross hairs up be the leg still doesn't bend right.  I can get it to work if I play around with the origins and the rotation but the green lines are then NOT lined up - they're rotated along the y and z .   How can you reset this properly?  Is there a tutorial step by step that would show something about this you can recommend? tks

This is a bit hard to visualize.  Some pictures would help.  For instance, what is the main axis of your ship, X or Z?  When you say "reposition" and "move" are you using translations as well as rotations to accomplish the action?  When you say "bend" do you mean fold?  The bend attribute should be turned off for mechanical joints.

I don't know of any tuts on this, but maybe someone else does.  I have done landing gear on many aircraft and would be glad to help, but illustrations would help a lot.

John

THanks.  Look at the pic.  The green center axis are not square to the leg.  Positioned like this with  a y offest of 11 degrees I can get the leg to move up and down on the X axis without twisting either on z or y so it works. My question is why can I not re-orient the center green lines to be "sqaure" to the backend of the leg as it was originally?  When I do - the leg rotates in along x AND y which I don't want.  I hope that helps....

Here's an overhead shot and you can see where the green lines are mis aligned. Again. I can't see why they won't reset to the new location of the leg which has moved via  x/y/z trans and a slight rotation of y.

Hi Hamiltonpl

As a back up plan make a morph of the landing gear coming down.  The reason I say that is to reduce the time spent as this appears to be a gymbal lock issue.

Cheers

Pat

Would that work as I am ultimately wanting to animate the movement....and I have no idea what a gymbal lock issue is.....So if I spawn the morph as legs down it should work with a 1.0 for legs down and a 0 for leg up but I don't know how this is different than just rotating the x axis....?

I'm not sure what Pat is getting at.  I don't think a morph will give you the action you want, and I doubt that's what he meant.  A morph doesn't have any way of recording rotation.  The beginning point and the end point would look alright, but it would only use a straight translation to get from one to the other.

Did you model it with the leg down, and then use the translations to give you a better starting point for the folding?  If so, this might fix it.

With the legs in the new position, export a new OBJ (leave export options as they are, and check the top box also).  BACKUP YOUR ORIGINAL FIRST.  Reopen Poser and load the object from the original CR2.  It will look like a mess, but that is to be expected.  Now zero your translations and rotations, and the legs should be where you intended.  Now try to rig it and it should react as you want.

John

This originally came to me as a pp2 or prop file. There are tons of pieces.  I don't know if it is referencing an OBJ and right now I just have it the way I want it in a pz3 file. 

I already tried exporting just the leg - the part the lowers and raises to an OBJ.  I imported it in and though I could move the green lines around etc. I did but as soon as I orient it to the spacecraft the same problem occurs..... I thought doing that yesterday would fix and zero everying out...I must be missing a step and thanks for all of your help.

Ah, I see what you're up against.  It must have been saved as a multi-part PP2,  if you haven't had to cut it up.  All is not lost, but it will take a little extra work to turn it into a figure.  That's really what would work best.

You need to export the whole thing as I advised above.  Then you need to import it to UVMapper and do some careful grouping.  Any part that needs to be posed separately should be assigned to its own group.  Everything else should constitute the main group.  Call it fuselage or something like that, but not body, to keep from confusing Poser.

Then to bring it back in as a figure you need to make a PHI file and load it that way.  I don't use the setup room, and I doubt that is any easier with a mechanical object.  The setup can be done in the pose room using the joint editor.

How to make the PHI file is a bit too much to explain here, so you can mail me at : BeyondVRataol.com (change the at to @)  There is a utility, PHI Builder or something like that, to do the job for you, but I have learned how to do them by hand since many of my models are too big for it.  If you can supply me with the exact names of the groups, and the hierarchy, I can make it for you.

It's up to you, but I doubt that you'll get too far with it as is.

John

What I meant was a morph instead of rigging. 

It's Gimbal lock.  Sorry for the mispelling.  Here's a link for an explanation.    http://www.anticz.com/eularqua.htm. 

Have you tried orienting it to the goal instead. 

BTW  I don't know if this will help,  but Poser uses the " joint envelope " rigging system.  If you are using a high end app look for it under your rigging options.  The only difference is Poser's scale is 42.55% less than the millimeter scale.  If you rig it in your high end app all you have to do is transfer the values via the joint editor.

Thank you.. That sounds way complicated. I have it working albeit in a "rigged" fashion. I may do this later and will hang onto this post for future reference. I was thinking that this might just be a "you didn't click this right" or " you missed this step" kind of issue.  But it sounds like a rebuild to get it into the right geometry orientation.....

You're welcome.  Unlike the high end apps Poser will force a rotation reorder if it runs into gimbal lock.  That being said,  steer clear of 45 and 90 degree angles on two axis.

I guess it does sound complicated if you haven't been doing it for years LOL.  For me its a one evening job.  Good luck, Hamilton!

John

Hi Hamiltonpl

I agree,  the " big picture "  is complicated,  but with the right information and work flow you'll find the smaller sections are much easier to handle. 

I'll stick with you on this if you'd like.  One thing I love is to talk shop.   Stop by the coffeehouse and say hi if you get the chance.  http://forum.daz3d.com/viewtopic.php?t=71525&start=414

Cheers

Pat