View Full Version : constructing a camera aperature type device...?

02 February 2003, 05:43 PM
Hey guys.

Im trying to figure out a quick way to create a 'sphincter' of the mechanical sort. I need to be able to have an opening open up with several overlapping plates that retract. I hope im making sense.... is there a good way to do this? expressions? nulls and parenting?

something like these:


PS. im going to test out just using a simple setup of a null with several plates parented to it, using matchgoal... but still would like some advice :)

02 February 2003, 05:46 PM
check here for a tutorial onthis:

I know I have seen 2 of I think Lost Pencil might have a scene file of this....or somebody does.... my mind is slowly getting rewired :)

02 February 2003, 05:53 PM
gawd proton,

you are on the ball. :)

thx for the fast reply. yeah, i have seen it somewhere too, but for the life of me, i cant find it. thx!

PS, yes its on lostpencil. shout out to them for the source file!

02 February 2003, 05:53 PM
I remember also one of tutorial about this, but unfortunately I don't remember where I saw it. Anyway, not sure 'bout this, but it just came into my mind. Only bad thing is that in this case, you would need each plate in separate layer. Setting their pivot point away from the center. To the outer .. uhm, rim?? Then inserting null there and parenting all plates to it. Then when rotating null, would rotate plates, and cause pivot point is far from the center, they would rotate around that pivot??? Tho, like I said, not sure 'bout this, but I think I might try it this way...

02 February 2003, 06:03 PM
I did a tutorial on it for NewTekniques mag years ago....trying to find that.....

02 February 2003, 06:55 PM
and it's called a mechanical iris, not a ... sphincter :wip:

02 February 2003, 07:05 PM
heh... well, arent they the same things, functionally? sphincter is just a word, not a butthole :surprised


02 February 2003, 10:56 PM
Hey Proton... any luck on finding that tutorial?

Im trying to reverse engingeer this scene from Lost Pencil and am running into problems...

namely, all the blades are even on the y axis when they are brought into modeler, but when i switch back to layout, they are tilted and a bit rotated (as they should be to ensure overlapping)... yet i cannot find out how he achieved this.

I went thru and rotated the bones on P and B just a little and got the desired look, set up my nulls... individual ones for each bone to target, and a parent Null to rotate them all...

heres the next problem... with each bone targeting an individual null in the center, full time IK on and match goal, (just like in the source file) the bone flips outward insted of staying put.... how do i get the individual nulls to work with these bones?

heres a shot


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