I have implemented a deformable fruit setup that is attached to a deformable thin strand using an attachment. I want to simulate fruit-plucking behavior using a manipulator. The strand needs to break (unattach) from the fruit when the manipulator holds and pulls it away.
I have looked into several forums but none addresses this issue. Has anyone encountered this situation? Any ideas for executing this simulation will be helpful.
Note: This is my first time putting up a post in this forum.
Hello, I’m sorry that I don’t know how to solve your problem, but may I ask you a few other questions?
I’m curious about how you connected the two deformable objects together in your setup. Are they part of the same URDF, or are they two independent? I’ve tried both approaches, but in the first case, I couldn’t generate the second deformable object, and in the second case, the soft objects just pass through each other and can’t connect properly.
Looking forward to your insights!
The two deformable objects I used are just 3D models imported from blender in USD format. Then you will have to convert those bodies to deformable bodies. You can only join two deformable bodies using attachments (not joints). I have never faced an issue where deformable bodies passed through each other. Can you provide some images/video to show it?
I’m sorry for the confusion. I didn’t notice that you were using Isaac Sim for your implementation and mistakenly thought you were using Isaac Gym. I apologize for wasting your time.
I appreciate your post, it made me realize that Isaac Sim can connect two deformable objects. This will be very helpful for my experiments.
Thank you!
Hi, I’m trying to build the deformable objects in Isaac Sim but I found the documentation is not that helpful.
Could you share how to create 3D models from Blender in USD format and how to attach and detach deformable objects?
I am trying to do something similar (dynamically enabling and disbábling attachments during simulation), did you find a solution? In my case I am working with cloth particles instead of deformable bodies but I think the solution should be similar?
In the GUI there is a bool property called attachmentEnabled, can this be accessed during simulation?
I could not find any solutions to disable attachments from python scripts in extension workflow or custom omnigraph nodes.
But I found another way to mimic object detachment when pulled, so I did the following:
In my case, when the object is pulled hard enough (using a manipulator robot), the fixed joint breaks and comes apart. Thus mimicking the effect of the object detaching from the main body.
I figured it out through trial and error. I’m not sure if it’s the right way to go, but it works for our application. I’m not sure if this will help you, but let me know if it does.
Yeah, the documentation is very confusing.
In the latest version of blender, you can export any 3D model as USD format and directly use it in Isaac Sim.
And with regards to implementing attachments for deformable bodies I looked through the physics demo scenes provided by Isaac sim as shown in the image.
Another useful reference : Deformable-Body Simulation — Omniverse Extensions
