# Grabbing Objects which are attached to different arms and pivot points

Hey Folks

I’ve been racking my brain at this and i need a solution or best yet a good direction.
i’m creating an interactive Operating Theatre and we have medical equipment hanging from the ceiling, the idea is to be able to say grab the OR monitors and move them into position, but how would we do this? because this equipment have 3/ different pivot points?

Here is the model

So in this scenario id want it so you can move the Monitor whilst its fixed to each arm.

Is there any examples of how to achieve this, Especially with VR and the ability to grab the object and move it

Best regards

I’m interested in this too.

I have tried something similar with no good solution.

You can use PhysicsConstraint Actors, which - in theory - works pretty well, UNTIL the phyicss go haywire. If the community could come up with a working solution, this would be great.

How does this system work and interact, do you think a similar set up would work ?

Make sure they aren’t set to collide with each other and have correct min/max extents. They shouldn’t go haywire if correctly set up.

I wouldn’t simulate physics on the thing you grab(i.e. screen). This is what the mounts are supposed to do IRL too. The arms could have physics and be attached to roofmount+screen, but the screen would just stop where you let it go.
If you wan’t realistic bobbing, sagging lamps that you can send flying in a circle, like at my dentists, this isn’t a good solution.

I have the exact same topic as you. I also work on simulation of hospital stuff and currently I’m cracking my head over pendants and OR-Lights. Maybe we could work together on this and find a solution together. Feel free to contact me! I would appreciate it.

However, I build a simple pendant and was playing around with physics constraints and I ended up getting pretty good settings for the constraints to have both arms move in a realistic matter. It isn’t that hard though. Just place the physics constraint actor where the pivot of rotation should be und you’re good to go for a simple rotation in at least one axis.

EDIT: I uploaded a video to youtube which shows what I got so far. Note that I am using a VR-Test Pawn because I can’t test with HMD right now. Link: UE4 Physics Constraints Actor Pendants Simulation VR - YouTube