I am completely new to blender so, if the question seems incorrect or stupid, please excuse & guide me to relevant site/page.

Here is what is want to achieve. I have the red object (it is a cylinder with cross section as below). Then I have the Blue object which is inside the red object (this is also as cylinder). Both of these are solid bodies so, one cannot penetrate the other. Now, what i want to do is to push the blue object with the green object and show how it tilts. How do I do this with Blender? Please let me know.


enter image description here


Push -

Not entirely clear how a hollow square can be a cylinder so I've done this as per your diagram.

All are 3D pieces and all are 'Rigid Bodies'.

The T-piece is suspended from a "Rgid Body Constraint" set to "FIXED". That's positioned well above.

I see now I'm back online that your T-piece isn't moving, but hinged. That is just a matter of lowering the constraint Empty down close to the T. You could also try with the constraint set to "Hinge".

The red outer container (Cylinder/box/whatever) is a passive rigid body.

The brown 'Pusher' is also passive but ticked as 'Animated' and keyframed to move left to right.

Addendum 8th March, 2021

A 2nd Blend file has been added below, this one without the Rigid Body Constraint. That allows the T-piece to sit on the box/cylinder and react to surfaces it comes into contact with. In an extreme case where the pusher moves excessively, it will, as in the real world, actually force the T up far enough to get underneath it.

With a normal stroke and without the RB Constraint to hinge the T piece, it is able to react with collision surfaces in the manner you're seeking and still in similar fashion to the movie clip above.

You'll notice the T-piece's physics 'Shape' has been changed to mesh and it's Collision Margin changed to .01 .

1st Blend file -

2nd Blend file -

  • $\begingroup$ I have one question if I may - Does it have to be done with physics? Animating this would be far easier for the inexperienced. $\endgroup$ – Edgel3D Mar 7 at 0:58
  • $\begingroup$ I want the whole set-up to behave naturally, hence I thought Physics would be better. I am not sure if it can be done with animation. Also, I have added the blend file I am working with so that it is clear what i am trying to do. Previously I did some animation so , the shaft is moving all over the place as soon as the animation starts & I don't know how to fix it. $\endgroup$ – moys Mar 8 at 1:54
  • $\begingroup$ Sorry if the file uploaded now is different from the question. I was just trying to keep things simple. The geometry may be different in the file I uploaded, but the underlying idea is the same, we have a hanging piece & I was to see how far it can be pushed before it stops moving sine there is no place for it to move (it collides with other objects & since all the objects are out of aluminum, they can't pass through each other). The shaft is being held by the pins from falling down. Thanks for your help. $\endgroup$ – moys Mar 8 at 2:04
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    $\begingroup$ I can't load your Blend file in my version 2.77 unfortunately. I have however added a 2nd Blend file, this one without the Rigid Body Constraint. The T piece isn't held in place and can fall onto the retaining surface that's holding it there. It can now freely react to surfaces it collides with. See the added notes for more detail. $\endgroup$ – Edgel3D Mar 8 at 16:21

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