I need help to RIG the window arms

I m have to do a animation of “Maxim Air” window but i just can’t do this rig make funcional, i try use IK and try to do with Constraint “track to”, but dosnt work.

In Red is where i try to pin the 3 arms in the frame,
Yellow is the where is need to fix in the window

but i cant “Lock” the bones in 2 objects e limit there movement

Pls anyone can help :smiley:

Doing this with 2 crossbars should be doable via a simple IK:

The third bar cannot be done (without insane complexity) with constraints alone. It needs to have wiggle room. One way to approximate it is to use a live boolean of a sphere with a box to acquire its position:

Here, the wiggle is on the window rather than the frame. I’m showing a non-rendering mesh with its modifiers disabled so you can see its base shape; all vertices are assigned to a group. The position that the middle bone should track describes the intersection of a sphere and a plane, so here I’m intersecting a sphere with a big enough box, then getting rid of everything but the intersecting plane with the mask modifier, and then giving it a 0 thickness wireframe to give me a surface to which I can shrinkwrap. A marker bone shrinkwraps to this mesh, then the middle arm tracks that marker. Here it is with modifiers re-enabled:

You could also do the middle bone with scripting, or geometry nodes modifiers (which could either recreate this modifier structure, or do the math to find the nearest intersection of a true sphere with a plane.)

Wiggle on the frame instead of the window would be similar. Wiggle on the strut itself is also possible, which is totally simple (track a marker bone that’s parented to the window or frame.)

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My last try i used IK Controls for each one

but this is happen

This is a shot in the dark, but it might be more stable if you put the object origin directly at the rotation axis, assuming it isn’t already.

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First, realize that one strut needs wiggle. That is part of how these structures work-- you can’t maintain three distances, only two.

Second, compare your IK setup to the one I offered in pics.

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