How to set mesh resolution in deformable body(Beta)?

Omniverse Isaac Sim
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Isaac Sim Version

5.0.0

Operating System

Ubuntu 24.04

Topic Description

Detailed Description

In the old version, we could set the number of mesh faces through resolution. However, in the new version, this option seems to have disappeared. Now, I can only set the number of mesh faces by setting the uvw axis parameters when creating a deformable body. So, how can we change the number of mesh faces on an existing deformable body.is there a tutorial?

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3

In Isaac Sim 5.x with the new “Deformable (Beta)” system, you do not directly set a single “mesh resolution” slider on the deformable body component; instead, resolution is controlled by (1) the input/source mesh density and (2) the remeshing/tet-mesh generation settings in the Omni/PhysX deformable schemas and authoring tools.

Where resolution actually comes from

  • The deformable simulation mesh is generated from your source mesh (often the render mesh), and its fineness is limited by how detailed that source mesh is.
  • For volume deformables, the tetrahedral or hexahedral simulation mesh is created by the authoring utilities (e.g. deformableUtils.create_auto_volume_deformable_hierarchy) and the underlying PhysX/Omni deformable schemas; there is no exposed “resolution: N” UI field like in the deprecated deformable system.

Key schema parameters affecting resolution

The beta deformable stack uses Omni Physics and PhysX API schemas where resolution-related controls are:

  • remeshingEnabled: Turn on/off automatic remeshing from the source mesh. When enabled, PhysX can adjust triangle density for the simulation mesh.
  • remeshingResolution: A numeric resolution parameter for remeshing; 0 means “auto”, larger values give a finer remeshed surface (more elements), at higher cost.
  • targetTriangleCount: Another control: 0 = automatic; otherwise you request a target number of triangles for the generated mesh.

These attributes are available on the PhysX deformable schema for the simulation mesh prim; in Kit/Isaac Sim you set them via the Property panel on the simulation mesh or by applying the PhysX deformable schema in Python and writing the attributes there.

To increase resolution in practice, you usually:

  • Start with a higher-resolution input mesh (subdivide in DCC or CAD tool).
  • Ensure remeshingEnabled is on and decrease element size indirectly by raising remeshingResolution or targetTriangleCount, then increase solver iterations (positionIterations) to keep the simulation stable.
1 Like
4

Thank you,i get it.i have an another question:whether the volume of object will effect the simulation?
As the following video,the big cube seems harder and the small cube looks softer.But i set the mass,mesh resolution and material of the two objects to be the same.

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And the height is the same as well.Would the mesh density have an impact？I guess in this case,the small cube has a greater mesh density.Is it really so?

6

Changing only the size/volume of a deformable object does not inherently make it “harder” or “softer”; perceived stiffness is primarily controlled by material parameters (Young’s modulus, Poisson’s ratio, density) and solver/discretization settings.

What actually controls stiffness

  • The deformation behavior of a deformable body in Isaac Sim’s Deformable (Beta) is governed by its deformable material, which includes Young’s modulus (stiffness), Poisson’s ratio (volume preservation), and density.
  • Higher Young’s modulus makes the body stiffer, while Poisson’s ratio near 0.5 makes it more volume-preserving but does not by itself depend on the object’s size.

Effect of size/volume

  • For a fixed material (same Young’s modulus and density) and similar mesh resolution, larger and smaller cubes should have the same “material stiffness”; a small cube is not automatically softer than a large cube.
  • However, mass scales with volume if you use density-based mass, so larger cubes will be heavier, which can cause larger absolute deformations under gravity or contact forces if you do not adjust thickness, support, or solver parameters.
  • If your small cubes share the same world-scale but fewer elements across their volume, their deformation can look larger relative to their size, giving the impression of being softer, even though the underlying Young’s modulus is identical.

How to keep behavior consistent across sizes

  • Keep material parameters the same for cubes that should have identical stiffness (same Young’s modulus and Poisson’s ratio) and use density or explicit mass so that mass scaling is predictable.
  • Ensure mesh quality is comparable in terms of “elements per characteristic length” when you scale objects, and if needed increase solver iterations or adjust time step so both small and large cubes converge similarly.