lRigging a Bathroom Mirror
This tutorial will result in an extendable mirror style rig where you can control the expansion of the mechanism simply by rotating one particular part.
1. Create a box (I used dimensions 100x10x5 for simplicity's sake) and name it ‘master01’ (the number after the names are important so they get numbered sequentially when the arms get cloned)
2. Clone the box, move it down 5 units (the thickness of the bar) and name it ‘slave01’
3. Click on ‘master01’ and go to the hierarchy panel, then click on 'Affect Pivot Only' under the 'Pivot' heading.
Then move the pivot 45 units to the end (moving it 45 units means that the pivot will be 5 units from the end and from each side.
Then rotate the pivot 180° around the X axis. (very important action, the master's Z axis must be the opposite of the slave's Z axis).
Click on 'Affect Pivot Only' again to disable it.
4. Create a dummy object and position it half way down the length of the bars, (use the Align tool for accuracy [Alt+A])
5. With the dummy object still selected, go to the hierarchy panel once again and click the 'Link Info' button at the top, then uncheck all the rotate boxes under the 'Inherit' rollout.
6. Clone ‘dummy01’ and move it 45 units to the far end of the bars (the opposite end to the pivot point of ‘master01’) just use the one axis needed, this should also now be 5 units from the end and sides.
7. Using the link tool:
link ‘dummy02’ to ‘slave01’
link ‘slave01’ to ‘dummy01’
link ‘dummy01’ to ‘master01’
8. VERY IMPORTANT BIT.....select both ‘master01’ and ‘slave01’, hold down 'Alt' and right click them, select 'Freeze rotation' in the top left corner of the menus.
9. deselect the two bars, reselect ‘master01’ and right click,
select 'Wire Parameters'
then 'Transform'
then 'Rotation'
then 'Keyframe XYZ'
then 'Z Rotation'
then click on ‘slave01’
then 'Transform'
then 'Rotation'
then 'Keyframe XYZ'
then 'Z Rotation'
A window will pop up, you need to click on the right hand arrow and then click on 'Connect' at the bottom, this links the z rotation of ‘slave01’, to the Z rotation of ‘master01’ (see pic)
10. If all being well you should now be able to rotate ‘master01’ and the ‘slave01’ will follow, if it doesnt check you have completed every step so far.
11. to get more bars select all four objects (‘master01’, ‘slave01’, ‘dummy01’ and ‘dummy02’) and cloe them, by holding down shift and clicking once on them, this will clone each object and increase its number by 1. Whuile they are still selected, move them exactly 90 unit down the barso the ends overlap
(note: they must be moved away from the pivot point of ‘master01’)
12. Using the link tool again, link ‘master02’ to ‘dummy02’.
13. Right click on ‘master01’ and...
select 'Wire Parameters'
then 'Transform'
then 'Rotation'
then 'Keyframe XYZ'
then 'Z Rotation'
then click on master02’
then 'Transform'
then 'Rotation'
then 'Keyframe XYZ'
then 'Z Rotation'
14. Select ‘dummy02’ and go to the hierarchy panel and uncheck all the rotate boxes under the 'inherit' rollout as before.
15. The set up should now work with both sets of arms just by rotating the first master object (‘master01’)
16. to add more arms just repeat 11-14 and change names accordingly,
17. When you have enough arm sections, create the mirror object (icluding the post below it) and link it to the very last dummy but uncheck all the ‘rotate’ check boxes in the link info area as in step 5, this enables the mirror to move with the dummy but not get affected when the dummy rotates.
I hope this tutorial was useful for you.