1
$\begingroup$

enter image description here

I would like to rotate LinkA1 (as shown in the image) and then have the entire articulating arm follow, either lengthening or shortening, using only constraints (no armature). I have been trying various methods using Copy Location and TrackTo constraints, but I keep failing to get it to work.

Can someone help me figure out if it is possible to rig such a thing using only constraints?

Here is the blend file if you are up to the challenge:

https://dl.dropboxusercontent.com/u/6647893/Forum_Help/ExtensionArmTest.zip

Improve this question
$\endgroup$

2 Answers 2

Reset to default
2
$\begingroup$

It is possible (by parenting anyway).

Have a look for now, I will write up the text soon.

enter image description here

enter image description here

Your Modified Blend File:

Improve this answer
$\endgroup$
3
  • $\begingroup$ Thanks Rick! I did figure it out with your help and wrote it all up so you wouldn't have to, but you beat me to it so thanks for all the time you spent helping me out. $\endgroup$
    – Bryson Jack
    Commented Mar 8, 2016 at 6:00
  • $\begingroup$ @BrysonJack, you are most welcome. If you did the write up, please append it to your question, so others less skilled could follow. If you don't mind of course. $\endgroup$
    – Rick Riggs
    Commented Mar 8, 2016 at 6:03
  • $\begingroup$ Yeah, I will post it as another answer. My solution was a bit different than yours (yours being simpler) because I am trying to solve a particular issue. I posted another question that is now more specific. I will also do a YouTube tutorial on all this once I am comfortable in my understanding of constraints. $\endgroup$
    – Bryson Jack
    Commented Mar 8, 2016 at 20:44
0
$\begingroup$

enter image description here

Parenting

Parent the following to LinkA1: LinkA1_Rivet Start, LinkA1_RivetMiddle and LinkA1_RivetEnd

Parent the following to LinkB2: LinkB2_Rivet Start, LinkB2_RivetMiddle and LinkB2_RivetEnd

Parent the following to LinkB1: LinkB1_Rivet Start

Parent the following to LinkA2: LinkA3_Rivet Start and LinkA2_EmptyMiddle

Parent LinkA2 and its children to LinkA2_EmptyStart

Parent LinkB1 and its children to LinkB1_EmptyEnd

Constraints

For LinkA2_EmptyStart: Add Object Constraint>Copy Location with Target: LinkA1_RivetEnd and X, Y, Z checked. Also Add Object Constraint>Copy Rotation with Target: LinkA1_RivetEnd and Z, Invert checked.

For LinkB1_EmptyEnd: Add Object Constraint>Copy Location with Target: LinkB2_RivetStart and X, Y, Z checked. Also Add Object Constraint>Copy Rotation with Target: LinkB2_RivetStart and Z, Invert checked.

For LinkB2: Add Object Constraint>Copy Location with Target: LinkA2_EmptyMiddle and X, Y, Z checked. Also Add Object Constraint>Copy Rotation with Target: LinkA1 and Z checked.

Improve this answer
$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .