Help Rope between 2 trackers

[Xameal]

Hello guys,

I need your help to find out if it's possible to create an Obi Rope between 2 trackers?
The idea is to make an extinguisher with a tracker on the "body" of the extinguisher, and an extinguisher at the end of the extinguisher nozzle with a hose connecting the 2 ends. As shown in the photo.

The problem is that the trackers on Unity (ViveTracker or Meta Quest controllers used as trackers) are always positioned at (0, 0, 0). What's more, the ropes are very sensitive to gravity, collisions etc... And so with the trackers always moving (or almost), the rope has trouble staying in place and does 'tricks'. For example, it always turns like a 'skipping rope' around an axis.

Has anyone tried this before? Do you have any advice for this particular case? I'm sure I'm not the first person to want to create a flexible linked by 2 trackers  .

[josemendez]

Hi,

What do you mean by "tracker"? do you mean an AR tracker, like a specific object or an image?

[Xameal]

Hi,

What do you mean by "tracker"? do you mean an AR tracker, like a specific object or an image?

In Virtual Reality, like the Vive Tracker or the Controller for Meta quest headset. It means that I fix my tracker on a real physical object, and in my game, that same object appears because I've modelled it with Blender. The photo below shows it:

Imagine this case with an extinguisher, where you want one tracker on the extinguisher (to hold it), and one tracker on the extinguisher nozzle (to aim at the point where you spray the fire). I have to represent de flexible cable between this 2 parts right ? So, I have to create a flexible rope between 2 trackers.

I hope it's more clear now  .

[josemendez]

It means that I fix my tracker on a real physical object, and in my game, that same object appears because I've modelled it with Blender. Imagine this case with an extinguisher, where you want one tracker on the extinguisher (to hold it), and one tracker on the extinguisher nozzle (to aim at the point where you spray the fire). I have to represent de flexible cable between this 2 parts right ? So, I have to create a flexible rope between 2 trackers.

I hope it's more clear now  

A tracker is just a regular transform then, only that it follows the motion of a real-word object? Doesn't matter where transform data comes from so in that case, using attachments should work fine.

The problem is that the trackers on Unity (ViveTracker or Meta Quest controllers used as trackers) are always positioned at (0, 0, 0).

That doesn't make any sense, there's only one 0,0,0 global coordinate at that's at the world space origin. If they were always positioned at 0,0,0 that would make them completely unable to move. Maybe you're referring to their position expressed in local space (that is, relative to their parent transform)? If so that's absolutely fine, it won't prevent attachments from working.

What's more, the ropes are very sensitive to gravity, collisions etc...

You can easily reduce both gravity and collision depenetration intensity. See the solver's settings.

And so with the trackers always moving (or almost), the rope has trouble staying in place and does 'tricks'. For example, it always turns like a 'skipping rope' around an axis.

This also doesn't sound right. No matter how much the trackers move the rope should stay in place when attached, which kind of attachments are you using? (static or dynamic)? Are you using ropes or rods? Also if using rods, are you constraining the attachment's orientation?

Assuming "trackers" are just transforms, and that their position is 0,0,0 in local space and not world space (which wouldn't make sense!), the simplest setup for this is to add the solver to the fire extinguisher itself to be able to have control over inertial forces, then add two static attachments to the rope: one to the extinguisher, another one to the nozzle. This should work fine, if it doesn't could you give more details about your setup?

kind regards,