Deformable Body Visualization Issues

Omniverse Isaac Sim
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1

Isaac Sim Version

4.5.0

Operating System

Ubuntu 20.04

GPU Information

  • Model: NVIDIA GeForce RTX 4090
  • Driver Version: 570.124.06

Topic Description

Detailed Description

  1. Visual Inconsistency Issue:
    When creating a cube with deformable body properties, the object only displays correct deformation behavior when viewing through the “Show by type → Physics → Deformable Body” simulation or collision views. In the default viewport, the deformable object shows unexpected distortions and doesn’t match the physical simulation shown in the physics views.

  2. Complex Deformable Creation:
    I’ve observed sophisticated hollow deformable tubes/hoses in the ORBIT-Surgical project (a NVIDIA-supported robotics research framework), which demonstrates advanced deformable body capabilities. I’m interested in understanding:

  • How to create such complex hollow deformable objects
  • How to ensure proper visualization of their physical deformations

Steps to Reproduce

  1. Create a cube prim in the scene
  2. Add deformable body properties to the cube
  3. Run the simulation
  4. Compare the object’s appearance between:
  • Default viewport
  • Show by type → Physics → Deformable Body → Simulation view

Screenshots

image
image1920×671 60.8 KB

a. Cube with normal deformation behavior in simulation view
b. Cube showing unexpected distortion in default viewport
c. Reference image from ORBIT-Surgical showing the hollow rubber tube implementation

Additional Context

I specifically need guidance on:

  • How to correctly set up deformable bodies (particularly rope-like and hollow tube-like objects) for proper visual representation
  • How to ensure consistency between physics simulation and visual rendering in the default viewport
1 Like
3

Hi @cwanli.liu, thank you for posting your question. We are currently looking into an issue where the Deformable Body Mesh does not match the visual mesh (similar to Meshes not connected to deformable objects). However, if you create meshes through the GUI you can get good match in the mesh visualization. An instructional video here:

If you want to simulate something like a medical tube, I suspect it will be challenging to do in Isaac Sim at the moment as the supported deformable mesh resolution is somewhat coarse. One alternative is to simulate in NVIDIA Warp.

Hope that helps!
Michael

4

Thank you for your response. I have two follow-up points:

  1. I followed the exact steps you mentioned to create the deformable body:
  • Create > Mesh > Cube
  • Right click the cube > Add > Physics > Deformable Body

However, I still observe the inconsistency between the default viewport and Simulation view.

  1. In the instructional video you shared, it appears to be showing only the Simulation view perspective. I’m specifically interested in knowing if the deformable body behaves correctly in the default viewport, as this is necessary for applying and viewing material properties/appearances.

Could you please clarify if there’s a way to achieve consistent deformation behavior in the default viewport? Or is this a known limitation that the visual mesh won’t match the physics simulation in the default view?

5

@cwanli.liu , @michalin

This is a very common problem. OmniPhysics deformable authoring does not automatically subdivide “skin meshes”. The user is responsible for that. I.e. if you create a mesh for deformable simulation in your favorite DCC tool, you need to make sure it’s sufficiently subdivided, so it has enough faces to be able to deform how you want to. In very limited ways, you can also do that in Isaac Sim for mesh primitives:

  1. Create (top level menu) > Mesh > Settings

  2. Primitive Type, e.g.: Cube > U verts scale = 3, V verts scale = 3, W verts scale = 30 (for this ctrl left click, and type)

  3. Create (button)

  4. RTX - Real-Time > Wireframe

  5. Select new Cube, Property > Change transform scale to (0.3, 0.3, 3.0)

  6. Create your deformable as you did before.

  7. Try again with more subdivisions if needed.

Cheers,
Simon

3 Likes
6

I have tried the solution proposed by @SimonPhysX and works perfectly. One change I did was to make the visual mesh more fine in the U and V axis also, I used (30, 30, 30).

1 Like