"Easy one" but sadly need help. Random expanding/contracting without scaling certain faces


I wonder if anyone can help please.
The question is two part.

  1. As part of a sci-fi turbine/engine, I’m am trying to open and close the forward points of this object, without them changing shape, or increasing/decreasing in size. While the back of the object is stationary.
    Is there a way to lock certain faces so they dont alter size/shape etc?

  2. I would then like each “spoke” to (again) open and close in an erratic random mode, like shaking with the heat from the jet thruster of the engine it will be attached to.

Is there a way to achieve this without having to manually setting each spoke in a position, applying a keyframe, rinse and repeat?.
Which will only result in the same pattern happening as the animation ends and starts again.

Appreciate any help.

why not trying to rigg it !?

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Hello and thank you so much for the reply.

I’m relatively new to Blender, and animation. And haven’t (As yet) done any rigging.

I also didn’t consider rigging, thinking a simple “open, and close” animation, while keeping the same shape would need to be rigged, is that the only way please?

Also would that overcome the “random” shake, movement of the spines? without having to do it manually.
I’m not sure if there is a procedural, or automated arbitrary modifier for animating parts.

Thank you again for any help.:slightly_smiling_face:

its ok

to be honest i am not a pro, but i know that ther are 3 ways of doing this,

1st way, is by animating the parts one by one, "thats if thy are individual objects "

2ne way, is if thy are all intact as one object, and using shape keys, but it might not be great , because it might change some size in the process

3rd way, is by rigging, and setting a bone foe each part, and just animate them,
it dosent matter if thy are one object or not,

thin you can add a nose modifier to the graph of the animation to create the “random shake"

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alf0 gives good advice… any of these methods could work if set up right, but rigging is probably the best option.

And I think he meant use the “Noise” modifier for adding the little bit of randomness to the base animation for each spoke.

The nose modifier if for face rigs only. :stuck_out_tongue_winking_eye: :lying_face:


PMSL - but it is good advice, I used the Nose Modifier on an aeroplane once, nearly worked… Didn’t Concorde have this Mod? :rofl: :rofl: :rofl: :rofl:


Seriously - rig this with a bone for each spoke, use either Transform Constraints, or Drivers, so what you do to one bone does the same for all the rest then you only have to animate one blade for the lot to move. You really must learn to rig with armatures for projects like this, undercarriages and control surfaces ae easily done with rigs, can be bloody hard work any other way…

Cheers, Clock. :beers:


Hey, Here is a quick example I put together (per Clocks instructions) :grin: - not really sure what type of ‘random movement’ you had in mind - post back if you have any questions.



Firstly let me apologise for not replying to this thread, its been a rough couple of days… :neutral_face:

But wow, you guys are the best!!
And I thank you all, for this stunning help.

Not only is Blender a game changer, even for a hobbyist like moi. But the community is the same quality.

I will now be exploring bones/rigging, its really about time I did. And the Noise modifier.

Thank again to all you guys for your help, and support. :partying_face:

And ajcdfin, oh yes, that is exactly what I was meaning, especially when the spines start going crazy at 100. Thank you so much for creating, and posting that, it will be a great help in the learning process.:sparkles:


Your welcome - glad to be of some help. I had a little more time to work on this, so I added a ‘driver’ function for a little different shake. Here is the new version



Hey ajcdfin.

First of all, please accept my sincere apologies for not answering this days ago.
I honestly did not mean to be impolite.

This is simply awesome.
This second more advance version is exactly what I wanted.
Thank you so much.

I really appreciate the help, and time you have spent.

Very Best.

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